Intravascular papillary endothelial hyperplasia (Masson's tumor) manifesting as a lateral neck mass.
Intravascular papillary endothelial hyperplasia is a benign lesion of vascular origin that is caused by an excessive proliferation of endothelial cells in normal blood vessels or vascular malformations. We report the case of a 26-year-old man who had such a lesion deep within the soft tissues of his neck. Imaging studies revealed a 6-cm-diameter mass, with its epicenter in the right retromandibular space. The mass extended into the right parapharyngeal space and compressed the pharynx. The mass was excised, and the patient recovered uneventfully. We discuss the management of this lesion, with emphasis on radiologic and histologic assessment and the differential diagnosis.
Unexplained swelling in the head and neck region poses a diagnostic dilemma for clinicians. One such difficult-to-diagnose entity is intravascular papillary endothelial hyperplasia (IPEH), also known as intravascular angiomatosis, Masson's pseudoangiosarcoma, and vegetant intravascular hemangioendothelioma. IPEH is a benign lesion of vascular origin that is caused by an excessive proliferation of endothelial cells in normal blood vessels or vascular malformations.
Although it is ubiquitous in nature,  IPEH has a predilection for the head and neck region. [2,3] Most of the reported head and neck cases have involved only the skin and the subcutaneous tissues of the face and scalp. [4-6] Less common sites include the buccal mucosa, [7,8] tongue, [9,10] pharynx,  masseter muscle,  and parotid gland.  IPEH of the maxillary sinus,  mandible,  orbit,  and ocular adnexa  has also been observed. Only five IPEH patients have been reported to have an anterior neck mass; one was in the external jugular vein,  one in the vasculature beneath the platysma muscle,  and three in organizing hematomas of the thyroid gland. [9,20] One case of IPEH in the superior vena cava that caused obstructive symptoms has also been reported. 
In this article, we report the case of a patient who had an IPEH deep within the soft tissues of the neck, which manifested as a lateral neck mass. We also describe its radiologic appearance on computed tomography (CT) and magnetic resonance imaging (MRI). In most previously reported cases, radiologic investigations either were not performed or their significance was not noted. The purpose of this report is to alert clinicians to the potential for misdiagnosing IPEH at the clinical, radiologic, and histologic levels, particularly those who are unfamiliar with this lesion.
A 26-year-old man came to the hospital 2 days after he had developed a painful swelling on the right side of his neck. He had no history of trauma or recent dental or oropharyngeal infection, and his medical history was unremarkable. On clinical examination, his oral temperature was 100[degrees]F (37.8[degrees] C) and his pulse rate was 90 beats per minute. General and systemic examinations were normal.
On his neck, a tender, noncystic, nonpulsatile mass measuring 5 x 4 cm extended from the angle of the right mandible into the parapharyngeal space. The mass appeared to be fixed to deeper tissues. The overlying skin was normal, and there were no palpable cervical nodes. There was no bruit, trismus, or intraoral sign of infection. The mass protruded into the pharynx and pushed the right tonsil and soft palate medially. The nose, nasopharynx, hypopharynx, larynx, and ears were normal on examination, and the cranial nerves were not involved. Complete blood count, serum electrolyte, and renal function measurements were normal, as was the chest x-ray. The patient tested HIV-negative.
After 3 days of treatment with a broad-spectrum antibiotic, indomethacin, and an antiseptic mouthwash, the patient's pain and temperature subsided, but the swelling persisted. CT was ordered, and it revealed a 6-cm-diameter mass. Its epicenter was located in the right retromandibular space. The mass extended into the right parapharyngeal space and compressed the pharynx. The lesion was clearly separate from the parotid gland. The mass was of low density on precontrast CT, and it displayed a peripheral enhancement on postcontrast scanning. Calcification was notably absent.
MRI confirmed that a well-defined nonhomogenous mass had abutted and eroded the medial side of the right mandibular ramus (figure 1). The mass exhibited a patchy central enhancement after the administration of gadolinium. Fine-needle aspiration on two occasions was not helpful because the aspirate consisted entirely of blood.
At surgery, a poorly encapsulated vascular mass was encountered in the region of the right tall of the parotid gland. The mass extended up toward the pterygoid plates and muscles. The surgeon ligated all small feeding vessels and excised the mass in its entirety.
Microscopic examination disclosed the presence of a myriad of papillary structures that were characterized by central collagenized cores, which were surrounded by an attenuated single layer of endothelium (figure 2). Dilated vessels, focal hemorrhage with hemosiderin deposition, and organizing thrombi were noted. The surrounding stroma featured a mononuclear inflammatory cell infiltrate. There was no cytologic atypia or necrosis. Examination of the adjacent parotid gland revealed a chronic sialadenitis with interstitial fibrosis. Postoperatively, the patient was left with a mild right mandibular facial palsy. One year later, he was well without any evidence of recurrence.
Clinically, IPEH usually manifests as a firm and sometimes tender mass that imparts a reddish-blue color to the overlying skin or mucous membrane. The age distribution is wide (9 mo-80 yr),  and most series report a slightly higher incidence among females. [23,24]
Because its clinical signs and symptoms are nonspecific, IPEH, like most other vascular malformations, poses a difficult diagnostic challenge.  This is particularly true with the deeper intramuscular lesions.  In our case, the patient's pain might have been caused by the compression of the parotid gland and other adjacent structures.
Radiologic evaluation. Radiologic investigations are integral to a rational approach to evaluating most lateral neck masses, particularly when the etiology is unclear. In our case, the patient's tumor displayed peripheral enhancement on postcontrast CT. On MRI, it produced a nonhomogenous signal postcontrast, with patchy central enhancement. An abscess can also show a central low-attenuation area and a contrast-enhancing rim on CT. Previous studies have shown that some IPEH masses are homogenous on CT and MRI, whereas others are nonhomogenous as well as contrast-enhancing. [26-30] Such signals are probably related to the fact that lesions are likely to have varying amounts of both solid "parenchymal" tissue areas (papillary structures and thrombi) and anastomotic, stagnant, or low-flow vascular channels.
Areas of microcalcification have been noted in IPEH lesions. [31,32] Phleboliths, however, are also common in patients with hemangiomas. Likewise, calcification can occur in hematomas and tumors, and they can follow necrosis of soft tissues. Moreover, on angiography, IPEH can manifest as either a vascular or avascular mass.  MRI is usually superior as the initial diagnostic test for vascular malformations, and further investigations are usually not necessary in low-flow lesions.  The CT, MRI, and angiographic patterns of IPEH can all simulate other benign (e.g., hemangioma ) and malignant (e.g., angiosarcoma ) conditions.
When Masson's tumor causes bone erosion as a result of pressure effects, its radiologic features can be even more suggestive of malignancy.[15,35] Therefore, while radiologic investigations can contribute to management, they are not sufficiently characteristic by themselves to make a diagnosis of IPEH. The diagnosis is best established with a histologic examination--or cytologically if the aspirate contains sufficient cells in addition to blood and fibrinoid material. [36,37]
Histologic evaluation. Microscopically, IPEH is a well-circumscribed lesion made up of stromal papillae that are lined with endothelial cells. These papillary structures can fuse to form an anastomosing vascular network, such as that associated with thrombosis. Inflammatory cells are usually few in number. In rare instances, a rupture of the vessel of origin permits the spilling over of proliferating endothelial cells into surrounding soft tissue, a phenomenon that should not be equated with malignancy. 
Pathogenesis. There are three types of JPEH: (1) a pure (primary) form that arises de novo in dilated vascular spaces, (2) a mixed (secondary or reactive) form that occurs focally in pre-existing varices, hemangiomas, and arteriovenous malformations, and (3) a rare extra vascular form that arises in hematomas.  The pathogenesis of IPEH remains speculative. Masson, in 1923, regarded this condition as a true neoplasm with secondary thrombosis.  However, its form of presentation, its association with other lesions, and its pattern of growth are more suggestive of a benign reactive process, perhaps related to trauma. [40, 41] Our patient had no such significant history.
The frequency with which thrombi are found in these lesions have led some authors to propose that IPEH represents an unusual form of thrombus organization. [42, 43] It is thought that once the thrombus develops, it serves as a matrix for the ingrowth of papillary structures.  Ultrastructurally, these papillary structures appear to closely resemble granulation tissue, which further suggests a reparative origin.  In further support of this view is the fact that the endothelium-lining cells seem to originate in histiocytes.  The exuberant endothelial proliferation involves an autocrine loop of endothelial secretion of basic fibroblast growth factor.  Reports of occasional cases that did not involve thrombosis in addition to reports of the presence of a lymphatic counterpart have led some authors to support Masson's original theory that JPEH is a benign tumor marked by primary endothelial proliferation and secondary thrombus formation. 
Differential diagnosis. We emphasize the importance of the differential diagnosis, particularly with respect to other conditions that have a predilection for the head and neck. Most significantly, IPEH can be mistaken for an angiosarcoma. [49,50] Other differential diagnoses include mucocele,  pyogenic granuloma,  Kaposi' s sarcoma,  and other vascular conditions such as hemangioma, angioendothelioma, papular angioplasia, Kimura's disease, bacillary angiomatosis, and intravenous atypical vascular proliferation. 
Microscopically, angiosarcoma usually exhibits an invasive growth pattern, cellular pleomorphism, frequent mitoses, and necrotic foci that are not seen in IPEH.  Although endothelial cells are also a prominent feature in pyogenic granuloma, no surrounding vascular wall is evident. Histologically, Kaposi's sarcoma has no papillary fronds; rather, it displays anastomosing slit-like vessels associated with a fascicular pattern of spindle-shaped cells, a plasma cell infiltrate, and hemosiderin pigment deposition. Detection of Bartonella organisms in histologic specimens distinguishes bacillary angiomatosis from IPEH. 
The importance of this report is that it stresses IPEH's likeness to, and therefore the difficulty in differentiating it from, similar benign and malignant conditions clinically, radiologically, and histologically. Conservative surgical excision is the treatment of choice. Invariably, the prognosis appears to be excellent, except for patients with intracranial lesions, which can be fatal.  Recurrence is extremely rare and is thought to occur only when the underlying vascular lesion is not excised completely. 
From the Department of Anatomical Pathology, South African Institute for Medical Research (Dr. Pantanowitz and Dr. Muc); the Department of Radiology, Chris Hani Baragwanath Hospital (Dr. Spanger); the Department of Anatomical Pathology, Chris Hani Baragwanath Hospital and the South African Institute for Medical Research (Dr. Sonnendecker); and the Department of Otorhinolaryngology, Johannesburg Teaching Hospitals (Dr. McIntosh) and the University of the Witwatersrand, Johannesburg, South Africa.
(1.) Enzinger FM, Weiss SW. Soft Tissue Tumors. St Louis: Mosby, 1995:614-9.
(2.) Corio RL, Brannon RB, Tarpley TM. Intravascular papillary endothelial hyperplasia of the head and neck. Ear Nose Throat J 1982;61:88-91.
(3.) McClatchey KD, Batsakis JG, Young SK. Intravascular angiomatosis. Oral Surg Oral Med Oral Pathol 1978;46:70-3.
(4.) Amerigo J, Matilla A, Gonzalez-Campora R, Galera-Davidson H. Vegetant intravascular hemangloendothelioma of the skin. Report of 3 cases with a critical pathogenetic study. Dermatologica 1979;159:476-81.
(5.) Cozzutto C, Guarino M, Dodero P, Nattero G. Intravascular endothelial proliferations in children. Am J Clin Pathol 1979;71:247-52.
(6.) Luce EB, Montgomery MT, Redding SW, Aufdemorte TB. Intravascular angiomatosis (Masson's lesion). J Oral Maxillofac Surg 1988;46:736-4.
(7.) Bodner L, Dayan D. Intravascular papillary endothelial hyperplasia of the mandibular mucosa. lot J Oral Maxillofac Surg 1991;20: 273-4.
(8.) Tosios K, Koutlas IG, Papanicolaou SI. Intravascular papillary endothelial hyperplasia of the oral soft tissues: Report of 18 cases and review of the literature. J Oral Maxillofac Surg 1994;52:1263-8.
(9.) Torne Escasany R, Umbert Millet P. Masson's pseudoangio-sarcoma of the tongue: Report of two cases. J Cutan Pathol 1985;12:66-71.
(10.) Stern Y, Braslavsky D, Shpitzer T, Feinmesser R. Papillary endothelial hyperplasia in the tongue: A benign lesion that may he mistaken for angiosarcoma. J Otolaryngol 1994;23:81-3.
(11.) Ejeckam GC, Orizaga M, Gerin-Lajoic J, Castilio G. Intravascular angiomasosis of the pharyox (Massons vegetant intravascular haemangioendothdioma)--a case report. Br J Oral Surg 1978;16:105-10.
(12.) Rodriguez Campo FJ, Monje Gil F, Chaves Benito A, et al. [Intravascular endothelial papillary hyperplasia in the masseter muscle]. Rev Stomatol Chir Maxillofac 199 l;92:420-4.
(13.) Lancaster JL, Alderson DI, Sherman IW, Clark AH. Papillary endothehial hyperplasia (Masson's tumour) of the maxillary sinus. J Larnyngol Otol 1998;112:500-2.
(14.) Komori A, Koike M, Kinjo T, et al. Central intravascular papillary endothelial hyperplasia of the mandible. Virchows Arch A Pathol Anat Histopathol 1984;403:453-9.
(15.) Weber FL, Babel J. Intravascular papillary endothelial hyperplasia of the orbit. Br J Ophthalmol 198l;65:18-22.
(16.) Werner MS, Hornblass A, Reifler DM, et al. Intravascular papillary endothelial hyperplasia: Collection of four eases and a review of the literature. Ophthal Plast Reconstr Surg 1997;13:48-56.
(17.) Pye JK. A case of Matson's vegetant, intravascular haemangio endothelioma presenting in a large neck vein. Clin Oncol l983;9:57-9.
(18.) Youngerman JS. Intravascular papillary endothelial hyperplasia. Arch Otolaryngol 1984;110:274-5, 277.
(19.) Chen KT. Extravascular papillary endothelial hyperplasia. J Surg Oncol 1987;36:52-4.
(20.) Hashimoto H, Daimaru Y, Enjoji M. Intravascular papillary endothelial hyperplasia. A clinicopathologic study of 91 cases. Am J Dermatopathol 1983;5:539-46.
(21.) Park JY, Chung-Park M, Snow M. Intravascular papillary endothelial hyperplasia of superior vena cava: A rare cause of the superior vena cava syndrome. Thorax 1991;46:272-3.
(22.) Clearkin KP, Enainger FM. Intravascular papillary endothelial byperplasia. Arch Pathol Lab Med 1976;100:441-4.
(23.) Kuo T, Sayers CP, Rosai J. Masson's "vegetant intravascular hemangioendothelioma": A lesion often mistaken for angiosarcoma: Study of seventeen cases located in the skin and soft tissues. Cancer 1976;38: 1227-36.
(24.) Amerigo J, Berry CL. Intravascular papillary endothelial hyperplasia in the skin and subcutaneous tissue. Virchows Arch A Pathol Anat Histol 1980;387:81-90.
(25.) Mulliken JE, Glowacki J. Hemangiomas and vascular malformations in infants and children: A classification based on endoshelial characteristics. Plast Reconstr Surg 1982;69:412-22.
(26.) Garber BE, Prestipino AJ, PollackHM, et al. Matson's tumor of the kidney: A new renal lesion. J Urol 1990;143:344-6.
(27.) Stern Y, Braslavsky D, Segal K, et al. Intravascular papillary endothelial hyperplasia in the maxillary sinus. A benign lesion that may be mistaken for angiosarcoma. Arch Otolaryngol Head Neck Surg 1991;117:1182-4.
(28.) Porter DG, Martin AJ, Mallucci CL, et al. Spinal cord compression due to Matson's vegetant intravascular hemangioendothelioma. Case report. J Neurosurg 1995;82:125-7.
(29.) Lam CH, Farmer JP, Meagher-Villemure K, Montes JL. Matson's vegetant haemangio-endothelioma. Pediatr Neurosurg 1995;23:93-6.
(30.) Johraku A, Miyanaga N, Sekido N, et al. A case of intravascular papillary endothelial hyperplasia (Matson's tumor) arising from renal sinus. Jpn J Clin Oncol 1997;27:433-6.
(31.) Kawashima A, Johsen T, Murayama S, Russell WJ. Intravascular papillary endothelial hyperplasia of the adrenal gland. Br J Radiol 1986;59:610-3.
(32.) Choi YW, Chang MS, Lee JS, Song CS. Intravascular papillary endothelial hyperplasia of the chest wall. AJR Am J Roentgenol 1994;163:475-6.
(33.) Kristof RA, Van Roost D, Wolf HK, Schramm J. Intravascular papillary endothelial hyperplasia of the sellar region. Report of three cases and review of the literature. J Neurosurg 1997;86:558-63.
(34.) Hovius SE, Borg DH, Psans PR, Pieterman H. The diagnostic value of magnetic resonance imaging in combination with angiography in patients with vascular malformations: A prospective study. Ann Plast Surg 1996;37:278-85.
(35.) Wehbe MA, Otto NR. Intravascular papillary endothelial hyperplasia in the hand. J Hand Surg [Am] 1986;11:275-9.
(36.) Garcia-Macias MC, Abad M, Alonso MJ, et al. Masson's vegetant intravascular hemagnioendothelioma. Fine needle aspiration cytology, histology and immunohistochemistry of a case. Acta Cytol 1990;34:175-8.
(37.) Perez-Guillermo M, Sola Perez J, Garcia Rojo B, Hernandez Gil A. Fine needle aspiration cytology of cutaneous vascular tumours. Cytopathology 1992;3:231-44.
(38.) Pins MR, Rosenthal DI, Springfield DS, Rosenberg AE. Florid extravascular papillary endothelial hyperplasia (Masson's pseudoangiosarcoma) presenting as a soft-tissue sarcoma. Arch Pathol Lab Med 1993;117:259-63.
(39.) Masson P. Hemangioendotheliome vegetant intravasculaire. Bull Soc Anat Paris 1923;93:517-23.
(40.) Axiotis CA, Merino MJ, Ain K, Norton JA. Papillary endothelial hyperplasia in the thyroid following fine-needle aspiration. Arch Pathol Lab Med 1991;15:240-2.
(41.) Rampoldi M, Bonica J, Remotti D. Extravascular papillary endothelial hyperplasia following surgery for De Quervain's disease. J Hand Surg [Br] 1997;22:116-8.
(42.) Salyer WR, Salyer DC. Intravascular angiomatosis: Development and distinction from angiosarcoma. Cancer 1975;36:995-l001.
(43.) Eusebi V, Fanti PA, Fedeli F, Mancini AM. Masson's intravascular vegetant hemangioendothelioma. Tumori 1980;66:489-98.
(44.) Steffee CH, Iskandar SS. Intravascular papillary endothelial hyperplasia in a thrombosed renal allograft vein. Hum Pathol 1996;27:986-9.
(45.) Kreutner A Jr., Smith RM, Trefny FA. Intravascular papillary endothelial hyperplasia: Light and electron microscopic observations of a case. Cancer 1978;42:2304-l0.
(46.) Albrecht S, Kahn HJ. Immunohistochemistry of intravascular papillary endothelial hyperplasia. J Cutan Pathol 1990;17:16-21.
(47.) Levere SM, Barsky SH, Meals RA. Intravascular papillary endothelial hyperplasia: A neoplastic "actor" representing an exaggerated attempt at recanalization mediated by basic fibroblast growth factor. J Hand Surg [Am] 1994;19:559-64.
(48.) Kuo T, Gomez LG. Papillary endothelial proliferation in cystic lymphangiomas. A lymphatic vessel counterpart of Masson's vegetant intravascular hemangioendothelioma. Arch Pathol Lab Med 1979;103:306-8.
(49.) Barr RJ, Graham JH, Sherwin LA. Intravascular papillary endothelial hyperplasia. A benign lesion mimicking angiosarcoma. Arch Dermatol 1978;l14:723-6.
(50.) Barua R, Munday RN. Intravascular angiomatosis in female urethral mass. Matson intravascular hemangioendothelioma. Urology 1983;21:191-3.
(51.) Williams HK, MacDonald DG. Intravascular angiomatosis in the mouth. Br Dent J 1982;152:414-5.
(52.) Reed CN, Cooper PH, Swerlick RA. Intravascular papillary endothelial hyperplasia. Multiple lesions simulating Kaposi's sarcoma. J Am Acad Dermatol 1984;10:110-3.
(53.) Rosai J, Akerman LR. Intravenous atypical vascular proliferation. A cutaneous lesion simulating a malignant blood vessel tumor. Arch Dermatol 1974;109:714-7.
(54.) Salyer WR, Salyer DC. Intravascular angiomatosis in cutaneous vessels [letter]. Arch Dermatol 1974;110:811-2.
(55.) Maurin M, Birtles R, Raoult D. Current knowledge of Bartonella species. Eur J Clin Microbiol Infect Dis 1997;16:487-506.
(56.) Chen TJ, Kuo T. Giant intracranial Masson's hemangioma. Report of a fatal case. Arch Pathol Lab Med 1984;108:555-6.
(57.) Katzman B, Caligiuri DA, Klein DM, et al. Recurrent intravascular papillary endothelial hyperplasia. J Hand Surg [Br] 1997;22:113-5.
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|Comment:||Intravascular papillary endothelial hyperplasia (Masson's tumor) manifesting as a lateral neck mass.|
|Author:||McIntos, William A.|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Oct 1, 2000|
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