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Adrenal schwannoma: a rare type of adrenal incidentaloma.

Adrenal incidentaloma, defined as an adrenal lesion found incidentally on autopsy or imaging, is a fairly frequent phenomenon. It has an incidence of approximately 4% to 6% in the general population. The differential diagnosis of adrenal incidentaloma can be extensive and ranges from cortical lesions such as adenoma and carcinoma to medullary lesions such as neuroblastoma, ganglioneuroma, and pheochromocytoma. (1-3) Adrenal schwannoma is a rare type of adrenal incidentaloma and is found in the medulla. There have been only 33 reported cases, 32 cases found in a review of the literature and 1 additional case reported in this article. (Table 1). Distinguishing the adrenal schwannoma from other entities, benign or malignant, simply based on imaging can be diagnostically challenging. All of the cases reported, with the exception of those found postmortem, were treated with surgical resection, with the possibility of a malignant tumor being the primary concern. Histologic sections, although diagnostic in many cases of conventional schwannoma, may not lead to a definitive diagnosis in cellular schwannoma. Ancillary studies such as immunohistochemistry and electron microscopy have helped in the diagnosis of these cases.

CLINICAL FEATURES

Schwannomas are benign nerve sheath tumors thought to arise from Schwann cells of peripheral, motor, sympathetic, or cranial nerves of the head and neck region and upper and lower extremities. They also may be found in the retroperitoneum and juxta-adrenal area. (2,4,5) Schwannomas presenting in visceral organs, especially the adrenal gland, however, are rare. The adrenal medulla is innervated by the phrenic nerve, the vagus nerve, and the sympathetic trunk. (6) Adrenal schwannomas are thought to arise from Schwann cells associated with these nerves. (2,4)

The cases reviewed in the literature demonstrate a broad age range, from 14 to 89 years, with a median age of 49 (Table 1). There is a slight female predominance, with a female to male ratio of 1.2:1. The majority of cases are detected incidentally, with the patient presenting because of some other medical problem. Thirteen out of 30 cases did present with symptoms, namely abdominal or flank pain and discomfort. The pain is likely attributable to mass effect of the tumor, as those tumors causing pain were greater than 5.0 cm in diameter.

All except 1 of the cases showed no clinical or biochemical evidence of endocrine hormonal activity. A metabolic workup typically includes serum electrolytes, cortisol, adrenocorticotropic hormone, aldosterone, renin, urinary catecholamines, metanephrines, vanillylmandelic acid, 17-ketosteroids, and 17-hydroxycorticoids. (2,7) The 1 case with abnormal laboratory findings showed an elevation of urinary catecholamines. (8)

Imaging studies performed include abdominal ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). For all 4 of the cases that describe ultrasound findings, a hypoechoic mass was shown. In 1 of those 4 cases, a cystic component to the mass was described on ultrasound. Computed tomography findings associated with adrenal schwannoma typically consist of well-circumscribed, homogenous masses. Long-standing schwannomas develop cystic degeneration manifesting as heterogeneous masses on CT. Calcifications can also be seen on CT of long-standing schwannomas. In addition, there is variable homogenous or heterogeneous enhancement with contrast. The heterogeneous enhancement is likely due to a variable degree of cellularity as well as cystic or hemorrhagic areas. (9) On MRI, the schwannoma shows low signal intensity on T1-weighted images and heterogeneous high signal intensity on T2-weighted images. (3,6-10) The heterogeneous high signal intensity on T2-weighted images can be attributed to the alternating Antoni A and B areas, which will be discussed in more detail in the histopathology section. (9)

Both CT and MRI are nonspecific in regard to the diagnosis of adrenal schwannomas. The differential diagnosis of a nonfunctional adrenal mass includes adrenal schwannoma, adrenal adenoma, adrenocortical carcinoma, adrenal metastasis, adrenal myolipoma, and neuroblastomas, which include neuroblastoma, ganglioneuroma, and ganglioneuroblastoma. Of these tumors, adrenal adenoma and adrenal myolipoma contain a fat component and can be differentiated on MRI. (6) Seventy percent of neuroblastomas can be distinguished from other tumors based on metaiodobenzyl guanidine scintigraphy. However, it is difficult to distinguish metaiodobenzylguanidine-negative neuroblastomas from schwannomas based on CT and MRI. Ganglioneuromas especially have the most similar imaging characteristics to schwannomas. On MRI, both schwannomas and ganglioneuromas typically show low signal intensity on T1-weighted images. Ganglioneuromas have curvilinear bands of low signal intensity on T2-weighted images, giving a whorled appearance. (6)

If the schwannoma contains degenerative changes such as cyst formation, calcifications, and hemorrhage, they may mimic pheochromocytoma or other malignant tumors such as malignant fibrous histiocytoma and liposarcoma on MRI. (10) Contrast enhancement does not differentiate pheochromocytoma and other malignancy from schwannoma, as one would see heterogeneous enhancement in both cases. (11)

Fine-needle aspiration biopsy of a suspected adrenal mass is controversial with respect to diagnostic accuracy and potential harm. (8) Although Jakowski et al (1) argue that a specific diagnosis of adrenal schwannoma can be made on fine-needle aspiration biopsy in most cases that have conventional histology, they do concede that the differential diagnosis based solely on fine-needle aspiration biopsy is broad and includes both malignant and benign entities. Another pitfall of fine-needle aspiration biopsy is that one can inadvertently sample a retroperitoneal or renal mass that may mimic an adrenal mass radiographically. Retroperitoneal schwannomas differ from adrenal schwannomas in that they can undergo malignant transformation and are potentially fatal. (1)

MANAGEMENT

The management of nonfunctional adrenal masses depends on whether one suspects that the mass is benign or malignant. A 2002 National Institutes of Health (12) state-of-the-science statement on the management of adrenal incidentalomas describes that the variables to consider are size of the lesion, its imaging characteristics, and its growth rate. It concludes that lesions greater than 6 cm should be excised, those less than 4 cm with imaging characteristics that appear benign should generally not be resected, and those between 4 cm and 6 cm can be either closely observed or resected. This conclusion was made under the assumption that the benign lesion in question was an adrenal adenoma, which is possible to distinguish radiographically given its fat component. Adrenal schwannomas, on the other hand, as described above, cannot reliably be differentiated from malignant lesions through imaging. In our review of the literature, all of the lesions, with the exception of those found postmortem, were surgically excised after being found on imaging studies, regardless of size.

The National Institutes of Health (12) state-of-the-science statement also comments that either open or laparoscopic adrenalectomy is an appropriate procedure for the resection of an adrenal mass. Although there are no prospective, randomized trials comparing the 2 procedures, the laparoscopic approach appears to be advantageous when performed by a surgical team experienced in the procedure. The advantages include decreased postoperative pain, reduced time to return of bowel function, decreased length of hospital stay, and the potential of earlier return to work. (12)

GROSS AND HISTOPATHOLOGIC FINDINGS

Our review of the literature reveals adrenal schwannomas ranging in size from 0.6 to 14.5 cm, with a median of 5.5 cm. The weight of the schwannomas ranges from 31.5 to 600 g. The median weight is 84 g. Sixteen of 31 cases were on the left side, 14 presented on the right side, and 1 patient presents with bilateral adrenal schwannomas (Table 1).

The majority of cases are firm, well-circumscribed rounded masses (Figure 1). They are described as tan-yellow to grayish-white in appearance. (8,13) Most are solid and homogenous throughout. The larger ones, however, show ancient change, with cystic areas, calcifications, and hemorrhage. (10) Adrenal schwannomas are thought to arise from the medulla, as there is continuity between the medulla and the tumor and an absence of a septum around the tumor. (6) The masses often compress surrounding medullary and cortical tissue. (1)

The histopathologic features of adrenal schwannomas are similar to those of schwannomas found in different sites. They are well circumscribed, but may or may not have a fibrous capsule. (1,13) Schwannomas can be categorized as either conventional or cellular schwannomas based on their histologic features. Conventional schwannomas consist of alternating compact cellular areas and loosely textured paucicellular areas, termed Antoni A and Antoni B respectively (Figure 2). (2,6) The Antoni A areas consist of fascicles of spindle cells with cytologically bland nuclei, indistinct cell borders, and faintly eosinophilic cytoplasm in a collagenous stroma. (1,3,13) Verocay bodies, nuclear-free zones in between regions of nuclear palisading, can be seen, as well as thick-walled, hyalinized blood vessels. (3,4,6,13) Reactive inflammatory cells and lymphoid aggregates can also be seen. The inflammatory infiltrate is typically seen at the periphery of the tumor. (1,4,13) Necrosis and mitotic figures are usually absent. (1,4)

Cellular schwannomas consist entirely of Antoni A areas with intersecting fascicles of spindle cells and are devoid of hypocellular, Antoni B areas. They are also characterized by an absence of Verocay bodies and may have increased mitotic activity. (4,13) The distinction between cellular and conventional schwannomas is an important one, as we shall see in our discussion on the differential diagnosis of adrenal schwannomas.

Some adrenal schwannomas may grow very large and show ancient change, with hemorrhage, calcifications, and cystic change. This corresponds with the degenerative changes seen on imaging and grossly. Ancient change also may result in nuclear atypia. This nuclear atypia should not be confused with malignancy. (1,8)

ANCILLARY STUDIES

Immunohistochemistry of adrenal schwannomas shows strong and diffuse staining for S-100 (Figure 3). They also display pericellular reactivity for collagen IV. (13) They are typically negative for CD117, desmin, CD34, HMB-45, synaptophysin, chromogranin, cytokeratin, and smooth muscle actin (Table 2). (1,2,4)

On electron microscopy, the tumor cells have long, thin cytoplasmic processes that are lined by continuous external lamina (Figure 4). They have oval nuclei with smooth nuclear contours, occasional small nucleoli, and moderately condensed chromatin. Cell junctions are present, but often are small and few in number (Figure 5). Myelin sheath formation may also be visualized. No cytoplasmic myofilaments, melanosomes, or neurosecretory granules are present. (1,4)

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of an adrenal schwannoma depends on whether it exhibits conventional or cellular histologic features. The diagnosis of conventional schwannomas can typically be made based on their distinctive histologic features that are described above, such as the alternating Antoni A and B areas, nuclear palisading, and Verocay bodies. Immunohistochemistry with S100 is used mainly for confirmation of the diagnosis. Cellular schwannomas, consisting almost entirely of intersecting fascicles of spindle cells, on the other hand, can present more of a problem in that they can mimic many other lesions with similar morphology.

Pheochromocytomas do not uncommonly present as spindle cell lesions. However, they typically display a nested architecture, unlike schwannomas. In addition, they are almost always positive for synaptophysin and chromogranin, unlike schwannomas as described above. Also, pheochromocytomas are negative for S100.

Another adrenal tumor that presents with intersecting fascicles of spindle cells is a ganglioneuroma. Although ganglioneuromas contain ganglion cells, there may be areas in the tumor where there is a paucity of these cells, giving an appearance of lesion composed entirely of spindle cells. Distinguishing the adrenal schwannoma from this tumor involves extensive sampling to ensure no ganglion cells are present, as this would be definite evidence for the presence of a ganglioneuroma.

Leiomyoma and solitary fibrous tumor are 2 rare mesenchymal adrenal lesions that also present as spindle cell lesions. Leiomyomas have similar architecture to schwannomas, with intersecting fascicles of spindle cells. The cellular features differ somewhat, with leiomyoma having blunt-ended nuclei with fibrillar cytoplasm, compared with tapered nuclei with afibrillar cytoplasm in schwannomas. Immunohistochemistry helps to definitely distinguish between the 2, with leiomyomas positive for desmin and smooth muscle actin, which are negative in schwannomas. (4) Solitary fibrous tumors are characterized by bland spindle cells with varying cellularity and a patternless architecture. This differs from the uniform cellularity of the cellular schwannomas. Immunohistochemical staining for CD34 and lack of reactivity for S100 is used to distinguish between the 2.

Gastrointestinal stromal tumors can also present as a spindle cell lesion in the adrenal gland. Gastrointestinal stromal tumors are positive for CD117 (c-kit). (3) Schwannomas, on the other hand, are negative for this marker.

Malignant melanoma, although it typically lacks bland cytomorphology, can present histologically as similar to a cellular schwannoma. In addition, both schwannoma and melanoma are positive for S100. However, positivity for other immunohistochemical studies such as HMB-45 and melan A can help differentiate it from schwannoma. (4)

Differentiating cellular schwannoma from other peripheral nerve sheath tumors such as neurofibroma, as well as a recently described tumor of the adrenal medulla called sustentaculoma, by histology and immunohistochemistry alone can be challenging. In these cases, electron microscopy can help to further classify the tumor.

Cellular schwannoma and neurofibroma both show a uniform pattern of spindle cells on histology. Theyboth also may show ancient change. On immunohistochemistry, they share positivity for S100, vimentin, and CD56, with variable expression of epithelial membrane antigen. (4,14) Electron microscopy can help to distinguish between these 2 entities. In contrast to the neurofibroma, which contains a mixture of cell types, the schwannoma consists almost exclusively of Schwann cells. (15)

Sustentaculoma arises from sustentacular cells of the adrenal medulla and may be the closest histologic mimic of adrenal schwannoma. It has uniform cytologically bland spindle cells and, like schwannoma, has an associated inflammatory infiltrate. Immunohistochemical staining shows diffuse and strong S-100. (16) Although both share the presence of complex interdigitated cytoplasmic processes on electron microscopy, sustentaculomas lack a well-defined basal lamina, one of the defining ultrastructural features of schwannomas. (16)

PROGNOSIS

Follow-up studies of adrenal incidentalomas show that the majority of adrenal lesions remain stable, 5% to 25% enlarge, and 3% to 4% decrease in size. Therefore, it is not unreasonable to follow up an adrenal incidentaloma with a CT scan 6 to 12 months after surgical excision. There are no data to support continued radiologic evaluation of lesions that do not increase in size. This is based on longitudinal studies that have shown that the risk of developing adrenal cortical carcinoma is extremely low. (12)

For adrenal incidentalomas diagnosed as adrenal schwannomas, the literature shows that follow-up after surgical resection is reported in 5 cases. One case is followed up at 18 months with CT. Another is followed up 3 times with ultrasound, at 6, 12, and 18 months. Three others are followed up at 5, 17, and 89 months with an unspecified imaging modality. None of these cases show evidence of recurrence or metastasis. (4,5,7,13)

CONCLUSION

Adrenal schwannoma, a type of adrenal incidentaloma, is rare. Correctly classifying this tumor can be challenging because imaging studies are nonspecific and many entities appear similar histologically. Immunohistochemical studies and electron microscopy are 2 ancillary techniques that can be used to help characterize adrenal schwannomas.

Caption: Figure 1. Adrenal gland with gray incidentaloma (open arrow) located predominantly in the medulla and pushing into cortex.

Caption: Figure 2. Adrenal schwannoma consisting of compact or loose interlacing fascicles of bland spindle cells (hematoxylin-eosin, original magnification 3100).

Caption: Figure 3. The spindle cells of this adrenal schwannoma are immunopositive for S-100 protein (IMPOX S-100, original magnification3100).

Caption: Figure 4. In this electron micrograph, the spindle cells of the schwannoma are surrounded by basal lamina (open arrow) (original magnification 33000).

Caption: Figure 5. Rudimentary junctional complexes (open arrow) are present between the spindle cells of the schwannoma (original magnification 320 000)

References

(1.) Jakowski JD, Wakely PE, Jimenez RE. An uncommon type of adrenal incidentaloma: a case report of a schwannoma of the adrenal medulla with cytological, histological, and ultrastructural correlation. Ann Diagn Pathol. 2008; 12:356-361.

(2.) Korets R, Berkenblit R, Ghavamian R. Incidentally discovered adrenal schwannoma. JSLS. 2007;11(1):113-115.

(3.) Onoda N, Ishikawa T, Toyokawa T, et al. Adrenal schwannoma treated with laparoscopic surgery. JSLS. 2008;12(4):420-425.

(4.) Lau SK, Spagnolo DV, Weiss LM. Schwannoma of the adrenal gland: report of two cases. Am J Surg Pathol. 2006;30(5):630-634.

(5.) Tarcoveanu E, Dimofte G, Bradea C, et al. Adrenal schwannoma. JSLS. 2009;13(1):116-119.

(6.) Suzuki K, Nakanishi A, Kurosaki Y, Nogaki J, Takaba E. Adrenal schwannoma: CT and MRI findings. Radiat Med. 2007;25(6):299-302.

(7.) Yang CY, Chou CW, Lin MB, Li CF. Schwannomas of the left adrenal gland and posterior mediastinum. J Chin Med Assoc. 2009;72(2):83-87.

(8.) Xiao C, Xu B, Ye H, Yang Q, Wang L, Sun YH. Experience with adrenal schwannoma in a Chinese population of six patients. J Endocrinol Invest. 2011; 34(6):417-421.

(9.) Rha SE, Byun JY, Jung SE, Chun HJ, Lee HG, Lee JM. Neurogenic tumors in the abdomen: tumor types and imaging characteristics. Radiographics. 2003; 23(1):29-43.

(10.) Inokuchi T, Takiuchi H, Moriwaki Y, et al. Retroperitoneal ancient schwannoma presenting as an adrenal incidentaloma: CT and MR findings. Magn Reson Imaging. 2006;24(10):1389-1393.

(11.) Richter KK, Premkumar R, Yoon HS, Mercer P. Laparoscopic adrenalectomy for a rare 14-cm adrenal schwannoma. Surg Laparosc Endosc Percutan Tech. 2011;21(6):e339-e343.

(12.) NIH state-of-the-science statement on management of the clinically inapparent adrenal mass ("incidentaloma"). NIH Consens State Sci Statements. 2002;19(2) 1-23.

(13.) Hsiao HL, Li CC, Lin HC, Yeh HC, Huang CH, Wu WJ. Adrenal schwannoma treated with laparoscopic adrenalectomy: a case report. Kaohsiung J Med Sci. 2008;24(10):553-557.

(14.) Wick MR, Hornick JL. Immunohistology of soft tissue and osseous neoplasms. In: Dabbs DJ, ed. Diagnostic Immunohistochemistry. Philadelphia, PA: Elsevier; 2010:98, 484.

(15.) Chang AE, Madewell JE, Rosenberg SA, Moser RP. Benign tumors of peripheral nerves. In: Enzinger FM, Weiss SW, eds. Soft Tissue Tumors. St Louis, MO: Mosby; 1988:733.

(16.) Lau SK, Romansky SG, Weiss LM. Sustentaculoma: report of a case of a distinctive neoplasm of the adrenal medulla. Am J Surg Pathol. 2006;30(2): 268-273.

(17.) Bedard YC, Horvath E, Kovacs K. Adrenal schwannoma with apparent uptake of immunoglobulins. Ultrastruct Pathol. 1986;10(6):505-513.

(18.) Watanabe Y, Nishikido M, Kubota S, et al. Neurinoma arising from the adrenal gland: a case report [in Japanese with English abstract]. Nishi Nippon Hinyoki. 1986;48:543-547.

(19.) Shimada K, Kobayashi T. A case of adrenal schwannoma [in Japanese]. Hinyoki Geka. 1991;4:1207-1210.

(20.) Nezasa S, Horie M, Kobayashi S, Shinoda T. Adrenal schwannoma in child: a case report [in Japanese with English abstract]. Rinnsho Hinyokika. 1992;46: 963-965.

(21.) Lack EE. Other unusual primary adrenal tumors. In: Atlas of Tumor Pathology 19. Tumors of the Adrenal Gland and Extra-Adrenal Paraganglia. Washington, DC: Armed Forces Institute of Pathology;1997: 188-189.

(22.) Igawa T, Hakariya H, Tomonaga M. Primary adrenal schwannoma. Nihon Hinyokika Gakkai Zasshi. 1998;89(5):567-570.

(23.) Yonou H, GoyaM, Miyazato M, etal. Retroperitoneal schwannoma arising from the adrenal area: a case report. Hinyokika Kiyo. 1999;45(6):403-405.

(24.) Gonzalez Gonzalez A, Perea R, Palacios Llopis S, et al. A benign adrenal schwannoma. Med Clin (Barc). 2000;115(13):518-519.

(25.) Pittasch D, Klose S, Schmitt J, et al. Retroperitoneal schwannoma presenting as an adrenal tumor. Exp Clin Endocrinol Diabetes. 2000;108(4): 318-321.

(26.) Ikemoto I, Yumoto T, Yoshino Y, Furuta N, Kiyota H, Oishi Y. Schwannoma with purely cystic form originating from the adrenal area: a case report. Hinyokika Kiyo. 2002;48(5):289-291.

(27.) Barrero Candau R, Ramirez Mendoza A, Morales Lopez A, et al. Benign adrenal schwannoma. Arch Esp Urol. 2002;55(7):858-860.

(28.) Arena V, De Giorgio F, Drapeau CM, Monego G, De Mercurio D, Capelli A. Adrenal schwannoma: report of two cases. Folia Neuropathol. 2004;42(3): 177-179.

(29.) Garg S, Mathew M, Goel T. Adrenal schwannoma: a case report and review of literature. Indian J Pathol Microbiol. 2007;50(3):587-588.

(30.) Kleiman DA, Hughes DB, Joshi AR. Surgical management of incidental adrenal schwannomas. Am Surg. 2011;77(5):E89-E90.

Yaseen Mohiuddin, MD; Mary G. F. Gilliland, MD

Accepted for publication July 6, 2012.

From the Department of Pathology and Laboratory Medicine, Brody School of Medicine at East Carolina University, Greenville, North Carolina.

The authors have no relevant financial interest in the products or companies described in this article.

Reprints: Yaseen Mohiuddin, MD, Department of Pathology and Laboratory Medicine, Brody School of Medicine at East Carolina University, Brody Medical Sciences Bldg 7S10, 600 Moye Blvd, Greenville, NC 27858-4353 (e-mail: mohiuddiny@ecu.edu).

Table 1. Clinical Features, Diagnostic Methods, Gross
and Microscopic Characteristics and Treatment of Adrenal Schwannomas

Source, y                            Country         Age, y/Sex

Bedard et al, (17) 1986              United States   63/F
Watanabe et al, (18) 1986            Japan           62/M
Shimada and Kobayashi, (19) 1991     Japan           49/F

Nezasa et al, (20) 1992              Japan           14/F
Lack, (21) 1997                      United States   29/F
Igawa et al, (22) 1998               Japan           45/M
Yonou et al, (23) 1999               Japan           67/F
Gonzalez Gonzalez et al, (24) 2000   Spain           NI/NI
Pittasch et al, (25) 2000            Germany         56/F
Ikemoto et al, (26) 2002             Japan           62/F
Barrero Candau et al, (27) 2002      Spain           53/M
Arena et al, (28) 2004               Italy           67/M
Arena et al, (28) 2004               Italy           89/M
Inokuchi et al, (10) 2006            Japan           35/F
Lau et al, (4) 2006                  United States   26/F

Lau et al, (4) 2006                  United States   73/M
Korets et al, (2) 2007               United States   70/M
Garg et al, (29) 2007                India           NI/NI
Suzuki et al, (6) 2007               United States   33/M
Onoda et al, (3) 2008                Japan           62/M
Jakowski et al, (1) 2008             United States   51/F
Hsiao et al, (13) 2008               Taiwan          49/M
Tarcoveanu et al, (5) 2009           Romania         55/M
Yang et al, (7) 2009                 China           30/F
Mohiuddin, 2011                      United States   79/M
Xiao et al, (8) 2011                 China           30/F
Xiao et al, (8) 2011                 China           38/F
Xiao et al, (8) 2011                 China           46/F
Xiao et al, (8) 2011                 China           43/F
Xiao et al, (8) 2011                 China           47/M
Xiao et al, (8) 2011                 China           39/M
Richter et al, (11) 2011             New Zealand     30/F
Kleiman et al, (30) 2011             United States   31/F

                                     Clinical         Diagnostic
Source, y                            Presentation     Modality

Bedard et al, (17) 1986              Abdominal pain   NI
Watanabe et al, (18) 1986            Incidental       US
Shimada and Kobayashi, (19) 1991     Incidental       US

Nezasa et al, (20) 1992              Abdominal pain   NI
Lack, (21) 1997                      NI               CT
Igawa et al, (22) 1998               Abdominal pain   US
Yonou et al, (23) 1999               Abdominal pain   US, CT
Gonzalez Gonzalez et al, (24) 2000   NI               NI
Pittasch et al, (25) 2000            Abdominal pain   US, CT, MRI
Ikemoto et al, (26) 2002             Abdominal pain   NI
Barrero Candau et al, (27) 2002      Flank pain       US, CT
Arena et al, (28) 2004               Incidental       Autopsy
Arena et al, (28) 2004               Incidental       Autopsy
Inokuchi et al, (10) 2006            Incidental       US, CT, MRI
Lau et al, (4) 2006                  Abdominal pain   NI
                                     and fever
Lau et al, (4) 2006                  Abdominal pain   CT
Korets et al, (2) 2007               Incidental       CT
Garg et al, (29) 2007                NI               NI
Suzuki et al, (6) 2007               Incidental       CT, MRI
Onoda et al, (3) 2008                Incidental       CT, MRI
Jakowski et al, (1) 2008             Incidental       CT
Hsiao et al, (13) 2008               Incidental       US, CT
Tarcoveanu et al, (5) 2009           Incidental       US, CT
Yang et al, (7) 2009                 Flank pain       CT, MRI
Mohiuddin, 2011                      Incidental       Autopsy
Xiao et al, (8) 2011                 Incidental       US, CT
Xiao et al, (8) 2011                 Incidental       US, CT
Xiao et al, (8) 2011                 Incidental       US, CT
Xiao et al, (8) 2011                 Abdominal pain   US, CT
Xiao et al, (8) 2011                 Incidental       US, CT
Xiao et al, (8) 2011                 Incidental       US, CT
Richter et al, (11) 2011             Abdominal pain   US, CT
Kleiman et al, (30) 2011             Abdominal pain   CT
                                     secondary to
                                     appendicitis

                                                  Tumor
Source, y                            Laterality   Diameter,
                                                  cm

Bedard et al, (17) 1986              L            9
Watanabe et al, (18) 1986            R            6.3
Shimada and Kobayashi, (19) 1991     R            5

Nezasa et al, (20) 1992              L            7.5
Lack, (21) 1997                      L            14
Igawa et al, (22) 1998               L            6.5
Yonou et al, (23) 1999               L            6
Gonzalez Gonzalez et al, (24) 2000   NI           NI
Pittasch et al, (25) 2000            R            12.4
Ikemoto et al, (26) 2002             R            12
Barrero Candau et al, (27) 2002      R            NI
Arena et al, (28) 2004               R            0.6
Arena et al, (28) 2004               R            1
Inokuchi et al, (10) 2006            Bilateral    7.5
Lau et al, (4) 2006                  R            10

Lau et al, (4) 2006                  R            9
Korets et al, (2) 2007               L            2.8
Garg et al, (29) 2007                NI           NI
Suzuki et al, (6) 2007               R            9
Onoda et al, (3) 2008                L            4.5
Jakowski et al, (1) 2008             L            5.5
Hsiao et al, (13) 2008               R            5
Tarcoveanu et al, (5) 2009           L            4.5
Yang et al, (7) 2009                 L            NI
Mohiuddin, 2011                      L            0.6
Xiao et al, (8) 2011                 L            3
Xiao et al, (8) 2011                 L            3.5
Xiao et al, (8) 2011                 L            4.5
Xiao et al, (8) 2011                 L            5.1
Xiao et al, (8) 2011                 L            6
Xiao et al, (8) 2011                 R            3.5
Richter et al, (11) 2011             R            14.5
Kleiman et al, (30) 2011             R            4.5

                                     Adrenal
Source, y                            Weight, g   Solid or    Antoni
                                                 Cystic      A or B

Bedard et al, (17) 1986              180         Solid       NI
Watanabe et al, (18) 1986            79          Solid       A, B
Shimada and Kobayashi, (19) 1991     60          Solid and   A, B
                                                 cystic
Nezasa et al, (20) 1992              115         Solid       A
Lack, (21) 1997                      NI          Cystic      A
Igawa et al, (22) 1998               75.5        Solid       A
Yonou et al, (23) 1999               50          NI          A
Gonzalez Gonzalez et al, (24) 2000   NI          NI          NI
Pittasch et al, (25) 2000            NI          Solid       A, B
Ikemoto et al, (26) 2002             600         Cystic      B
Barrero Candau et al, (27) 2002      NI          Solid       NI
Arena et al, (28) 2004               NI          Solid       A
Arena et al, (28) 2004               NI          Solid       A
Inokuchi et al, (10) 2006            88          Cystic      A, B
Lau et al, (4) 2006                  200         NI          A

Lau et al, (4) 2006                  190         NI          A, B
Korets et al, (2) 2007               65          NI          A
Garg et al, (29) 2007                NI          NI          NI
Suzuki et al, (6) 2007               NI          Solid       A
Onoda et al, (3) 2008                60          Solid       A
Jakowski et al, (1) 2008             84          Cystic      A, B
Hsiao et al, (13) 2008               31.5        NI          A
Tarcoveanu et al, (5) 2009           NI          NI          A
Yang et al, (7) 2009                 NI          NI          A, B
Mohiuddin, 2011                      NI          Solid       A
Xiao et al, (8) 2011                 NI          NI          A, B
Xiao et al, (8) 2011                 NI          NI          A, B
Xiao et al, (8) 2011                 NI          NI          A, B
Xiao et al, (8) 2011                 NI          NI          A, B
Xiao et al, (8) 2011                 NI          NI          A, B
Xiao et al, (8) 2011                 NI          NI          A, B
Richter et al, (11) 2011             312         NI          NI
Kleiman et al, (30) 2011             NI          NI          NI

Source, y                            Surgical Procedure

Bedard et al, (17) 1986              Open adrenalectomy
Watanabe et al, (18) 1986            Open adrenalectomy
Shimada and Kobayashi, (19) 1991     Open adrenalectomy

Nezasa et al, (20) 1992              Open adrenalectomy
Lack, (21) 1997                      NI
Igawa et al, (22) 1998               NI
Yonou et al, (23) 1999               NI
Gonzalez Gonzalez et al, (24) 2000   NI
Pittasch et al, (25) 2000            NI
Ikemoto et al, (26) 2002             NI
Barrero Candau et al, (27) 2002      NI
Arena et al, (28) 2004               NI
Arena et al, (28) 2004               NI
Inokuchi et al, (10) 2006            Laparoscopic adrenalectomy
Lau et al, (4) 2006                  NI

Lau et al, (4) 2006                  NI
Korets et al, (2) 2007               Laparoscopic adrenalectomy
Garg et al, (29) 2007                NI
Suzuki et al, (6) 2007               NI
Onoda et al, (3) 2008                Laparoscopic adrenalectomy
Jakowski et al, (1) 2008             Laparoscopic adrenalectomy
Hsiao et al, (13) 2008               Laparoscopic adrenalectomy
Tarcoveanu et al, (5) 2009           Laparoscopic adrenalectomy
Yang et al, (7) 2009                 Laparoscopic adrenalectomy
Mohiuddin, 2011                      NI
Xiao et al, (8) 2011                 Open adrenalectomy
Xiao et al, (8) 2011                 Open adrenalectomy
Xiao et al, (8) 2011                 Open adrenalectomy
Xiao et al, (8) 2011                 Open adrenalectomy
Xiao et al, (8) 2011                 Open adrenalectomy
Xiao et al, (8) 2011                 Open adrenalectomy
Richter et al, (11) 2011             Laparoscopic adrenalectomy
Kleiman et al, (30) 2011             Laparoscopic adrenalectomy

Abbreviations: A, Antoni A; B, Antoni B; CT, computed
tomography; MRI, magnetic resonance imaging; NI, not indicated;
US, ultrasound.

Table 2. Immunohistochemical Studies Performed on Adrenal Schwannomas

Source, y                     Country         Age,    Immunohisto
                                              y/Sex   chemical Stains

                                                      CD34   CD56

Lack, (21) 1997               United States   29/F    ND     ND
Inokuchi et al, (10) 2006     Japan           35/F    ND     ND
Lau et al, (4) 2006           United States   26/F    -      ND
Lau et al, (4) 2006           United States   73/M    -      ND
Korets et al, (2) 2007        United States   70/M    -      ND
Suzuki et al, (6) 2007        United States   33/M    -      ND
Onoda et al, (3) 2008         Japan           62/M    -      ND
Jakowski et al, (1) 2008      United States   51/F    ND     ND
Hsiao et al, (13) 2008        Taiwan          49/M    ND     ND
Tarcoveanu et al, (5) 2009    Romania         55/M    ND     ND
Yang et al, (7) 2009          China           30/F    -      ND
Mohiuddin, 2011               United States   79/M    ND     +
Xiao et al, (8) 2011          China           30/F    ND     ND
Xiao et al, (8) 2011          China           38/F    ND     ND
Xiao et al, (8) 2011          China           46/F    ND     ND
Xiao et al, (8) 2011          China           43/F    ND     ND
Xiao et al, (8) 2011          China           47/M    ND     ND
Xiao et al, (8) 2011          China           39/M    ND     ND
Richter et al, (11) 2011      New Zealand     30/F    ND     ND

Source, y                     Immunohistochemical Stains

                              CD117   COL4   HMB45   MART-1   S100

Lack, (21) 1997               ND      ND     ND      ND       +
Inokuchi et al, (10) 2006     ND      ND     ND      ND       +
Lau et al, (4) 2006           ND      +      -       -        +
Lau et al, (4) 2006           ND      +      -       -        +
Korets et al, (2) 2007        -       ND     -       ND       +
Suzuki et al, (6) 2007        ND      ND     ND      ND       +
Onoda et al, (3) 2008         -       ND     ND      ND       +
Jakowski et al, (1) 2008      ND      ND     -       ND       +
Hsiao et al, (13) 2008        ND      ND     ND      ND       +
Tarcoveanu et al, (5) 2009    ND      ND     ND      ND       +
Yang et al, (7) 2009          ND      ND     ND      ND       +
Mohiuddin, 2011               ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Xiao et al, (8) 2011          ND      ND     ND      ND       +
Richter et al, (11) 2011      -       ND     ND      ND       +

Source, y                     Immunohistochemical Stains

                              SMA   DES   VIM   KER   SYN   CHR   INH

Lack, (21) 1997               ND    ND    ND    ND    ND    ND    ND
Inokuchi et al, (10) 2006     ND    ND    ND    ND    ND    ND    ND
Lau et al, (4) 2006           -     -     ND    -     -     -     ND
Lau et al, (4) 2006           -     -     ND    -     -     -     ND
Korets et al, (2) 2007        ND    -     ND    ND    ND    ND    ND
Suzuki et al, (6) 2007        -     ND    ND    ND    ND    ND    ND
Onoda et al, (3) 2008         -     -     ND    ND    ND    ND    ND
Jakowski et al, (1) 2008      -     ND    ND    -     ND    ND    -
Hsiao et al, (13) 2008        ND    ND    ND    ND    ND    ND    ND
Tarcoveanu et al, (5) 2009    -     ND    ND    ND    ND    ND    ND
Yang et al, (7) 2009          ND    ND    ND    ND    ND    ND    ND
Mohiuddin, 2011               ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Xiao et al, (8) 2011          ND    ND    +     ND    ND    ND    ND
Richter et al, (11) 2011      -     -     ND    ND    ND    ND    ND

Source, y                     Immunohistochemical Stains

                              EMA

Lack, (21) 1997               ND
Inokuchi et al, (10) 2006     ND
Lau et al, (4) 2006           ND
Lau et al, (4) 2006           ND
Korets et al, (2) 2007        ND
Suzuki et al, (6) 2007        ND
Onoda et al, (3) 2008         ND
Jakowski et al, (1) 2008      ND
Hsiao et al, (13) 2008        ND
Tarcoveanu et al, (5) 2009    ND
Yang et al, (7) 2009          ND
Mohiuddin, 2011               -
Xiao et al, (8) 2011          ND
Xiao et al, (8) 2011          ND
Xiao et al, (8) 2011          ND
Xiao et al, (8) 2011          ND
Xiao et al, (8) 2011          ND
Xiao et al, (8) 2011          ND
Richter et al, (11) 2011      ND

Abbreviations: CHR, chromogranin;COL4, collagen IV; DES, desmin;EMA,
epithelial membrane antigen;INH, inhibin; KER, keratin;ND, not done;
SMA, smooth muscle actin; SYN, synaptophysin; VIM, vimentin.


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Author:Mohiuddin, Yaseen; Gilliland, Mary G.F.
Publication:Archives of Pathology & Laboratory Medicine
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Geographic Code:1USA
Date:Jul 1, 2013
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