Printer Friendly

Mucinous Cystadenoma of the Urachus and Review of Current Classification of Urachal Mucinous Cystic Neoplasms.

The urachus, a midline tubular structure, represents an embryologic remnant of the allantois, the cephalic extension of cloaca that connects the anterior dome of the bladder and the umbilicus. Involution of the tubular structure of the urachus usually takes place before birth, most often during early infancy, which results in fibrous obliteration of its lumen and the formation of the median umbilical ligament. Urachal remnants may persist in approximately 32% of adults, (1) and clinically they can present as patent urachus (most common), umbilical-urachal sinus, vesicourachal diverticulum, and urachal cyst (second most common) depending on which portion of the urachus persists. Histologically, its lumen is lined by urothelial epithelium or columnar glandular epithelium. The wall is formed by smooth muscle in continuation with the muscularis propria of the bladder. Persistency of urachus after infancy may give rise to a variety of benign and malignant neoplasms, most frequently, noncystic adenocarcinoma. (2) Although urachal adenocarcinomas represent less than 1% of all bladder malignancies, they account for approximately 10% to 30% of all reported bladder adenocarcinomas. (3-5) Mucinous cystic tumors are rare and have not been well studied because of their rarity. In contrast to mucinous cystic tumors arising from other organs, benign urachal mucinous cystic tumors are even rarer than their malignant counterparts. Only a few cases of benign urachal mucinous cystadenomas have been documented in the literature to date. Because of its rarity, the clinical and pathologic characteristics are still not well defined. We reviewed the literature and summarized the clinical presentation, pathologic features, management, and prognosis of this extremely rare entity.

CLINICAL PRESENTATIONS

After a thorough review of English literature, we found only 9 previously reported cases of mucinous cystadenoma of the urachus, including a case we recently encountered. (6-11) The clinicopathologic characteristics of these cases are summarized in Table 1. Cystadenomas mostly are found in middle-age adults. The patient's age when the tumor was identified ranged from 15 to 70 years, with a mean of 43.4 years. Cystadenoma is evenly distributed between the sexes with cases involving 5 women and 4 men. The patients usually presented initially with some unspecific symptoms, such as hematuria, urinary frequency, and vague lower abdominal pain. Rarely, in the case of a cyst rupture, the patient might present with severe and acute abdominal pain. On the other hand, a portion of the patients did not have any tumor-associated symptoms, and the tumor was found incidentally by palpation or imaging for other causes (Figure 1).

PATHOLOGIC FINDINGS

The average size of the urachal mucinous cystadenoma was 7.9 cm at greatest dimension, ranging from 1.5 cm to 15.5 cm. On gross examination, those tumors were well-circumscribed, cystic, and filled with abundant mucin. They could be either multilocular or unilocular (Figure 2). Histologically, the epithelial lining on the cyst wall was a single layer of mucinous, cuboidal or columnar cells. The epithelial lining can be flat or denuded. Focal pseudostratification and rare mitosis were occasionally seen, but by definition, these tumors are devoid of complex architectural abnormalities or nuclear atypia. Chronic lymphocytic infiltration, multinucleated giant cell reaction, fibrosis, and calcification of the cyst wall are frequently identifiable. These tumors should be free of any invasive or microinvasive foci after thorough examination (Figure 3).

DIFFERENTIAL DIAGNOSIS

The most common differential diagnoses of urachal mucinous cystadenoma include villous adenoma, mucinous cystic tumor of low malignant potential (MCTLMP), and mucinous cystadenocarcinoma.

Only a few urachal glandular tumors are considered completely benign. Villous adenomas and mucinous cystadenomas compose most benign urachal glandular neoplasms. The distinction between urachal villous adenomas and mucinous cystadenomas is based on architectural and cytologic features. The former usually presents with a prominent villopapillary structure, lined by dysplastic mucinous epithelium, arising in a field of otherwise nondysplastic urachal remnant epithelium. In contrast, a mucinous cystadenoma displays unilocular or multilocular cystic spaces, lined by a single layer of nondysplastic cuboidal or columnar epithelium. (2)

According to the updated World Health Organization (WHO) classification, (12) MCTLMP may have a stratified cyst lining with no more than 3 layers of epithelial cells. The lining in MCTLMP may show some structural abnormalities, such as pseudopapillary and villous patterns. The MCTLMP allows mild to moderate nuclear atypia, but mitosis is not common within the lining.

The presence of papillary or cribriform structures with focal or diffuse severe nuclear atypia and a high level of mitosis upgrades the lesion to cystadenocarcinoma, either intraepithelial or invasive. If stromal invasion is less than 2 mm and comprises less than 5% of the tumor, the tumor should be diagnosed as mucinous cystadenocarcinoma with microinvasion. More extensive invasion will lead to a diagnosis of invasive mucinous cystadenocarcinoma.

IMMUNOHISTOCHEMISTRY

Urachal mucinous cystic tumors are mainly diagnosed on histologic features. In most cases, immunohistochemistry stains are unnecessary and are not performed. However, in cases of distant metastases of cystadenocarcinoma, it is of clinical importance to determine whether they are of urachal origin through immunophenotyping. Most urachal mucinous cystic tumors stain positively with CK20 (100%) and CDX2 (80%) and are negative for nuclear [beta]-catenin, estrogen receptor, and progesterone receptor staining. CK7 staining is also seen in about 30% of the cases. (13)

TREATMENT AND PROGNOSIS

Surgical treatment, such as mass excision, urachectomy, or urachectomy combined with partial cystectomy, is the first-line and definitive treatment for mucinous cystadenomas of the urachus. All 9 reported patients with mucinous cystadenoma survived the tumor without evidence of recurrence for up to 97 months of follow-up. In summary, mucinous cystadenomas are clinically benign processes and have an excellent prognosis after complete surgical removal.

DISCUSSION AND CONCLUSION

Urachal neoplasms are uncommon and usually remain undiscovered for a long period because of their obscured location. They are frequently found incidentally or at an advanced stage of malignancy. Although there are nonglandular tumors reported in the urachus, (14) most urachal neoplasms are glandular. In contrast to neoplasms in most other organs, most glandular neoplasms in the urachus are adenocarcinomas.

Because of the rarity of cystic urachal tumors, there is a notable inconsistency in the nomenclature, diagnostic criteria, and tumor staging in the literature. Paner et al (2) recently proposed a uniform nomenclature, which was adopted by the 2016 WHO classification of urologic tumors. In the updated WHO book, urachal mucinous cystic tumors are classified into 3 entities: cystadenoma, cystadenocarcinoma, and in between, MCTLMP. This classification scheme is very similar to the classification of cystic tumors in ovaries, which has been supported by abundant clinical data. Although only limited clinical data are currently available on cystic tumors in the urachus, we believe this updated classification will certainly facilitate collection of more clinical data by clinicians on these rare lesions.

Historically, the cutoff line between cystadenoma and cystic tumor with uncertain or low potential was vague, and the nomenclature was sometimes confusing. We reviewed the pathology of the reported cases and reassigned the low grade urachal tumors to cystadenoma or MCTLMP groups, according to the new WHO classification (Tables 1 and 2). For instance, a case reported by Hubens and colleagues (15) was diagnosed as urachal adenoma in the article, but the histology showed a prominent papillary structure and epithelial stratification. We classified that case as MCTLMP. In contrast, another case, which was called urachal cystadenoma in the original article, showed columnar cells and pseudostratification on the epithelial lining. (8) We classified that case into the mucinous cystadenoma category. In 1986, Eble et al (16) summarized 16 urachal adenoma cases with mucusuria from the literature, and some of them might fit in the mucinous cystadenoma category according to today's nomenclature. However, because of the lack of histologic images of those cases, we are not able to further analyze them. Historically, noninvasive, mucinous, cystic neoplasms with mild architectural abnormality and nuclear atypia have been named differently. Because of their good prognosis, they were mostly labeled as low or unknown malignant potential. The 2016 WHO classification of urologic tumors categorizes them as MCTLMP, reflecting the benign clinical process of the disease. In comparison to mucinous cystadenoma, MCTLMP shows proliferative, stratified epithelium with mild to moderate architectural abnormalities and nuclear atypia. We compared the clinicopathologic features of all reported mucinous cystadenoma and MCTLMP cases (Tables 1 and 2). The mean age of the 32 patients with MCTLMP was 49.9 years with youngest at 26 years and oldest at 80 years. (6,15,17-26) There is no difference in age distribution between the mucinous cystadenoma group and the MCTLMP group (mean age, 43.4 [18.7] versus 49.9 [16.2]; P = .53 by Student t test). The tumor size in the MCTLMP group varied from 2 cm to 14 cm, with a mean of 5.4 cm. Those data suggest that a mucinous cystadenoma is likely larger than a MCTLMP (mean size, 7.9 cm [5.1] versus 5.4 cm [2.3]) when it is identified. The size difference is statistically significant despite the small sample (Student t test, P = .048). No sex predilection was shown either in mucinous cystadenomas or in MCTLMP (male to female ratio: mucinous cystadenoma group, 4:5; MCTLMP group, 17:15). Similar to mucinous cystadenoma, the treatment for MCTLMP is surgical removal of the tumor. After surgical treatment, MCTLMP cases also showed excellent prognosis. Except for one MCTLMP case in which the patient died of other causes, (6) all MCTLMP patients were free of recurrence or metastasis for up to 84 months of follow-up.

Pseudomyxoma peritonei is a clinical condition characterized by extensive intraperitoneal spread of mucus associated with a variety of mucinous tumors. Although the appendiceal and ovarian neoplasms have been implicated as the most common causes, rarely, tumors originating from other sites, including urachal remnants, are also associated with the development of pseudomyxoma peritonei. Most of the few cases reported to be caused by urachal mucinous tumors are invasive mucinous cystadenocarcinoma. (24) Reviewing all reported mucinous cystadenoma and MCTLMP cases, we identified 2 patients who presented with pseudomyxoma peritonei; both showed low-grade dysplasia but no invasion in histology. (24,25) Both cases were reported as adenocarcinoma in situ but were categorized as MCTLMP according to the new WHO classification. None of the reported mucinous cystadenoma cases was associated with pseudomyxoma peritonei.

In contrast to the excellent prognosis of urachal mucinous cystadenoma and MCTLMP, urachal mucinous cystadenocarcinoma has a poor prognosis even with aggressive treatments. It has been believed that malignant transformation of mucinous cystadenoma gives rise to urachal mucinous cystadenocarcinoma. The mucinous cystadenocarcinomas are more likely to have pseudomyxoma peritonei and other clinical symptoms than mucinous cystadenomas and MCTLMPs. (6) Five year survival rates for invasive urachal adenocarcinoma are only about 45%. (27) Therefore, thorough sampling and precise diagnoses of those lesions are of great importance in terms of prognosis prediction and guiding treatment of the disease. Because they are usually asymptomatic, cystadenoma and MCTLMP are frequently underdiagnosed. In consideration of the sampling bias, we speculate the true incidence of urachal mucinous cystadenoma or MCTLMP is indeed somewhat higher. To avoid missing the potential malignant component, a thorough examination and generous sampling are pivotal for accurately diagnosing these lesions.

References

(1.) Schubert GE, Pavkovic MB, Bethke-Bedurftig BA. Tubular urachal remnants in adult bladders. J Urol. 1982;127(1):40-42.

(2.) Paner GP, Lopez-Beltran A, Sirohi D, Amin MB. Updates in the pathologic diagnosis and classification of epithelial neoplasms of urachal origin. Adv Anat Pathol. 2016;23(2):71-83.

(3.) Bruins HM, Visser O, Ploeg M, Hulsbergen-van de Kaa CA, Kiemeney LA, Witjes JA. The clinical epidemiology of urachal carcinoma: results of a large, population based study. J Urol. 2012;188(4):1102-1107.

(4.) Pinthus JH, Haddad R, Trachtenberg J, et al. Population based survival data on urachal tumors. J Urol. 2006;175(6):2042-2047.

(5.) Wright JL, Porter MP, Li CI, Lange PH, Lin DW. Differences in survival among patients with urachal and nonurachal adenocarcinomas of the bladder. Cancer. 2006;107(4):721-728.

(6.) Amin MB, Smith SC, EbleJN, etal. Glandular neoplasms of the urachus: a report of 55 cases emphasizing mucinous cystic tumors with proposed classification. Am J Surg Pathol. 2014;38(8):1033-1045.

(7.) Gupta S, Bhaijee F, Harmon EP. Mucinous neoplasm arising in a urachal cyst: a first in the pediatric population. Urology. 2014;83(2):455-456.

(8.) Hull MT, Warfel KA. Urachal cystadenoma with abundant glycogen: ultrastructural study. Ultrastruct Pathol. 1994;18(5):499-502.

(9.) Saha S, Jha A, Gupta S. Urachal mucinous cystadenoma. Saudi J Kidney Dis Transpl. 2011;22(6):1256-1258.

(10.) Schell AJ, Nickel CJ, Isotalo PA. Complex mucinous cystadenoma of undetermined malignant potential of the urachus. Can Urol Assoc J. 2009;3(4): E39-E41.

(11.) Wang D, Kauffman E, Sule N. Mucinous cystadenoma of the urachus: a case report and review of the literature [abstract]. Am J Clin Pathol. 2016; 146(suppl 1):57.

(12.) Busch C, Johansson SL. Urothelial papilloma; Sauter G. Inverted papilloma. In: Moch H, Humphrey PA, Ulbright TM, Reuter VE, eds. WHO Classification of Tumours of the Urinary System and Male Genital Organs. 4th ed. Lyon, France: IARC Press; 2016:113-114. World Health Organization Classification of Tumours; vol 8.

(13.) Paner GP, McKenneyJK, Barkan GA, etal. Immunohistochemical analysis in a morphologic spectrum of urachal epithelial neoplasms: diagnostic implications and pitfalls. Am J Surg Pathol. 2011;35(6):787-798.

(14.) Paner GP, Barkan GA, Mehta V, et al. Urachal carcinomas of the nonglandular type: salient features and considerations in pathologic diagnosis. Am J Surg Pathol. 2012;36(3):432-442.

(15.) Hubens G, De Vries D, Hauben E, et al. Laparoscopic resection of an adenoma of the urachus in combination with a laparoscopic cholecystectomy. Surg Endosc. 1995;9(8):914-916.

(16.) Eble JN, Hull MT, Rowland RG, Hostetter M. Villous adenoma of the urachus with mucusuria: a light and electron microscopic study. J Urol. 1986; 135(6):1240-1244.

(17.) Carr NJ, McLean AD. A mucinous tumour of the urachus: adenoma or low grade mucinous cystic tumour of uncertain malignant potential? Adv Clin Path. 2001;5(3):93-97.

(18.) Chahal D, Martens M, Kinahan J. Mucinous cystic tumour of low malignant potential presenting in a patient with prior non-seminatous germ cell tumour. Can UrolAssoc J. 2015;9(9-10):E750-E753.

(19.) Choi JW, LeeJH, Kim YS. Urachal mucinous tumor of uncertain malignant potential: a case report. Korean J Pathol. 2012;46(1):83-86.

(20.) Fahed AC, Nonaka D, Kanofsky JA, Huang WC. Cystic mucinous tumors of the urachus: carcinoma in situ or adenoma of unknown malignant potential? Can J Urol. 2012;19(3):6310-6313.

(21.) Pasternak MC, Black JD, Buza N, Azodi M, Gariepy A. An unexpected mass of the urachus: a case report. Am J Obstet Gynecol. 2014;211(4):e1-e3.

(22.) Paul AB, Hunt CR, Harney JM, Jenkins JP, McMahon RF. Stage 0 mucinous adenocarcinoma in situ of the urachus. J Clin Pathol. 1998;51(6):483-484.

(23.) Prakash MR, Vijayalaxmi SV, Maitreyee R, Ranjit KP. Complex mucinous cystadenoma of undetermined malignant potential of the urachus: a rare case with review of the literature. Malays J Pathol. 2014;36(2):145-148.

(24.) Shinohara T, Misawa K, Sano H, Okawa Y, Takada A. Pseudomyxoma peritonei due to mucinous cystadenocarcinoma in situ of the urachus presenting as an inguinal hernia. Int J Clin Oncol. 2006;11(5):416-419.

(25.) Stenhouse G, McRae D, Pollock AM. Urachal adenocarcinoma in situ with pseudomyxoma peritonei: a case report. J Clin Pathol. 2003;56(2):152-153.

(26.) Wang LL, Liddell H, Tanny ST, Norris B, Appu S, Pan D. Incidental finding of a rare urachal pathology: urachal mucinous cystic tumour of low malignant potential. Case Rep Urol. 2016;2016:5764625.

(27.) Gopalan A, Sharp DS, Fine SW, et al. Urachal carcinoma: a clinicopathologic analysis of 24 cases with outcome correlation. Am J Surg Pathol. 2009; 33(5):659-668.

Diping Wang, MD, PhD; Norbert Sule, MD, PhD

Accepted for publication December 20, 2017.

Published online November 6, 2018.

From the Department of Pathology and Anatomical Science, State University of New York, Buffalo (Dr Wang); and the Department of Pathology, Roswell Park Cancer Institute, Buffalo (Dr Sule).

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

Corresponding author: Norbert Sule, MD, PhD, Department of Pathology, Roswell Park Cancer Institute, Elm & Carlton Street, Buffalo, NY 14263 (email: Norbert.sule@roswellpark.org).

Caption: Figure 1. An example of urachal mucinous cystadenoma. Magnetic resonance imaging shows a multilocular cystic mass in the pelvis.

Caption: Figure 2. Gross image of a urachal mucinous cystadenoma showing a well-circumscribed yellow multilocular cystic lesion filled with abundant mucus.

Caption: Figure 3. A, Epithelial lining on the septa of a multilocular cystadenoma; one side is denuded, and the other side is lined by a single layer of flat epithelium. B, The lining epithelium on the cyst wall composed of a single layer of tall columnar cells with abundant apical mucin. C, Pseudostratification and goblet cell-like cells are present on the cyst wall. D, Lymphoid aggregates, blood vessels, and smooth muscle bundles are present within the cyst wall (hematoxylin-eosin, original magnifications X200 [A and D] and X400 [B and C]).
Table 1. Clinicopathologic Characteristics of Mucinous Cystadenoma
of the Urachus

Source, y                   Age,    Presentation                  Size,
                            y/Sex                                  cm

Hull and Warfel, (8) 1994   32/M    Incidental finding             14
Schell et al, (10) 2009     70/F    Lower abdominal mass          15.5

Saha et al, (9) 2011        60/F    Urinary frequency               3
Amin et al, (6) 2014        59/M    Hematuria, mass                 7
Amin et al, (6) 2014        33/M    Abdominal pain/cyst rupture    13
Amin et al, (6) 2014        24/F    Microhematuria                 1.5

Amin et al, (6) 2014        42/F    NA                              5
Gupta et al, (7) 2014       15/F    Lower abdominal pain           4.5

Wang etal, (11) 2016        56/M    Incidental finding             7.5
[abstract]

Source, y                   Gross

Hull and Warfel, (8) 1994   Multilocular
Schell et al, (10) 2009     Multilocular

Saha et al, (9) 2011        Unilocular
Amin et al, (6) 2014        NA
Amin et al, (6) 2014        NA
Amin et al, (6) 2014        NA

Amin et al, (6) 2014        NA
Gupta et al, (7) 2014       Unilocular

Wang etal, (11) 2016        Multilocular
[abstract]

Source, y                   Original Reported Diagnosis

Hull and Warfel, (8) 1994   Urachal cystadenoma
Schell et al, (10) 2009     Mucinous cystadenoma of
                            undetermined malignant potential
Saha et al, (9) 2011        Mucinous cystadenoma
Amin et al, (6) 2014        Mucinous cystadenoma
Amin et al, (6) 2014        Mucinous cystadenoma
Amin et al, (6) 2014        Mucinous cystadenoma

Amin et al, (6) 2014        Mucinous cystadenoma
Gupta et al, (7) 2014       Low grade mucinous neoplasm with
                            uncertain malignant potential
Wang etal, (11) 2016        Mucinous cystadenoma
[abstract]

Source, y                   Treatment             Follow-up,   Status
                                                      mo

Hull and Warfel, (8) 1994   Mass excision             NA       NA
Schell et al, (10) 2009     Partial cystectomy        12       AWOD

Saha et al, (9) 2011        Excision of mass          NA       NA
Amin et al, (6) 2014        Partial cystectomy        97       AWOD
Amin et al, (6) 2014        Mass excision             11       AWOD
Amin et al, (6) 2014        Partial cystectomy,       1        AWOD
                            urachectomy
Amin et al, (6) 2014        Mass excision             NA       NA
Gupta et al, (7) 2014       Urachectomy               NA       NA

Wang etal, (11) 2016        Excision of mass          12       AWOD
[abstract]

Abbreviations: AWOD, alive without disease; NA, not available.

Table 2. Clinicopathologic Characteristics of Urachal Mucinous
Cystic Tumor of Low Malignant Potential (MCTLMP)

Source, y                    Age,    Presentation
                             y/Sex

Hubens et al, (15) 1995      40/M    Incidental finding
Paul et al, (22) 1998        68/M    Hematuria and mucusuria

Carr and McLean et al,       72/M    Microscopic hematuria, nocturia
  (17) 2001
Stenhouse et al, (25) 2003   54/M    Abdominal pain
Shinohara et al, (24) 2006   54/M    Incidental finding
Choi et al, (19) 2012        29/F    Right flank pain

Fahed et al, (20) 2012       66/M    Lower abdominal and groin pain

Amin et al, (6) 2014         48/F    Mass

Amin et al, (6) 2014         26/F    Mass
Amin et al, (6) 2014         74/M    Incidental finding

Amin et al, (6) 2014         72/M    Mucusuria
Amin et al, (6) 2014         74/M    Hematuria
Amin et al, (6) 2014         50/F    Mass
Amin et al, (6) 2014         45/M    Hematuria and abdominal pain
Amin et al, (6) 2014         58/F    Incidental finding
Amin et al, (6) 2014         43/F    Incidental finding
Amin et al, (6) 2014         40/F    Incidental finding

Amin et al, (6) 2014         80/F    Mucusuria

Amin et al, (6) 2014         37/F    Incidental finding
Amin et al, (6) 2014         29/F    Bladder dome nodule
Amin et al, (6) 2014         42/F    Pelvic mass
Amin et al, (6) 2014         42/F    Midline cystic mass
Amin et al, (6) 2014         36/F    Incidental finding
Amin et al, (6) 2014         39/M    Obstruction and umbilical
                                       discharge
Amin et al, (6) 2014         57/M    NA

Amin et al, (6) 2014         77/F    NA
Amin et al, (6) 2014         43/M    Incidental finding

Amin et al, (6) 2014         26/M    Urgency, abdominal pain
Pasternak et al, (21) 2014   28/F    Incidental finding

Prakash et al, (22) 2014     58/M    Lower abdominal pain

Chahal et al, (18) 2015      37/M    Incidental finding

Wang et al, (26) 2016        54/M    Incidental finding

Source, y                    Size,   Gross
                             cm

Hubens et al, (15) 1995      8       Unilocular
Paul et al, (22) 1998        3       Unilocular

Carr and McLean et al,       4       Multilocular
  (17) 2001
Stenhouse et al, (25) 2003   14      Unilocular
Shinohara et al, (24) 2006   9       Unilocular
Choi et al, (19) 2012        5.5     Multilocular

Fahed et al, (20) 2012       9       Unilocular

Amin et al, (6) 2014         8       NA

Amin et al, (6) 2014         2       NA
Amin et al, (6) 2014         6.5     NA

Amin et al, (6) 2014         0.8     NA
Amin et al, (6) 2014         3       NA
Amin et al, (6) 2014         2.1     NA
Amin et al, (6) 2014         3.5     NA
Amin et al, (6) 2014         1       NA
Amin et al, (6) 2014         2.5     NA
Amin et al, (6) 2014         6       NA

Amin et al, (6) 2014         2.5     NA

Amin et al, (6) 2014         NA      NA
Amin et al, (6) 2014         NA      NA
Amin et al, (6) 2014         8       NA
Amin et al, (6) 2014         6       NA
Amin et al, (6) 2014         NA      NA
Amin et al, (6) 2014         6.5     NA

Amin et al, (6) 2014         2.8     NA

Amin et al, (6) 2014         5.5     NA
Amin et al, (6) 2014         7       NA

Amin et al, (6) 2014         8       NA
Pasternak et al, (21) 2014   8       Multilocular

Prakash et al, (22) 2014     10      Multilocular

Chahal et al, (18) 2015      4       Unilocular

Wang et al, (26) 2016        4       Unilocular

Source, y                    Original Reported Diagnosis

Hubens et al, (15) 1995      Urachal adenoma
Paul et al, (22) 1998        Stage 0 mucinous adenocarcinoma
                               in situ
Carr and McLean et al,       Adenoma of unknown malignant
  (17) 2001                    potential
Stenhouse et al, (25) 2003   Urachal adenocarcinoma in situ
Shinohara et al, (24) 2006   Mucinous cystadenocarcinoma
Choi et al, (19) 2012        Mucinous tumor of uncertain
                               malignant potential
Fahed et al, (20) 2012       Adenocarcinoma in situ

Amin et al, (6) 2014         MCTLMP with intraepithelial
                               carcinoma
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP

Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP

Amin et al, (6) 2014         MCTLMP

Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP

Amin et al, (6) 2014         MCTLMP with intraepithelial
                               carcinoma
Amin et al, (6) 2014         MCTLMP
Amin et al, (6) 2014         MCTLMP

Amin et al, (6) 2014         MCTLMP
Pasternak et al, (21) 2014   Mucinous urachal neoplasm of
                               low malignant potential
Prakash et al, (22) 2014     Mucinous cystadenoma of undetermined
                               malignant potential
Chahal et al, (18) 2015      MCTLMP

Wang et al, (26) 2016        MCTLMP

Source, y                    Treatment

Hubens et al, (15) 1995      Laparoscopic resection of mass
Paul et al, (22) 1998        Partial cystectomy

Carr and McLean et al,       Partial cystectomy
  (17) 2001
Stenhouse et al, (25) 2003   Laparotomy
Shinohara et al, (24) 2006   Partial cystectomy
Choi et al, (19) 2012        Excision of mass

Fahed et al, (20) 2012       Excision of mass and partial
                               cystectomy
Amin et al, (6) 2014         Partial cystectomy

Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Mass excision and sigmoid
                               colectomy
Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Resection of urachus
Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Mass excision
Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Partial cystectomy, urachectomy,
                               and umbilectomy
Amin et al, (6) 2014         Partial cystectomy and
                               urachectomy
Amin et al, (6) 2014         NA
Amin et al, (6) 2014         NA
Amin et al, (6) 2014         Excision of pelvic mass
Amin et al, (6) 2014         NA
Amin et al, (6) 2014         NA
Amin et al, (6) 2014         Umbilectomy and urachectomy

Amin et al, (6) 2014         Partial cystectomy

Amin et al, (6) 2014         Partial cystectomy
Amin et al, (6) 2014         Partial cystectomy, urachectomy,
                               and umbilectomy
Amin et al, (6) 2014         Partial cystectomy
Pasternak et al, (21) 2014   Umbilectomy, urachectomy,
                               partial cystectomy
Prakash et al, (22) 2014     Excision of mass

Chahal et al, (18) 2015      Partial cystectomy, left
                               hydrocelectomy
Wang et al, (26) 2016        Umbilectomy, urachectomy,
                               partial cystectomy

Source, y                    Follow-up,   Status
                             mo

Hubens et al, (15) 1995      NA           NA
Paul et al, (22) 1998        12           AWOD

Carr and McLean et al,       NA           NA
  (17) 2001
Stenhouse et al, (25) 2003   6            AWOD
Shinohara et al, (24) 2006   84           AWOD
Choi et al, (19) 2012        11           AWOD

Fahed et al, (20) 2012       12           AWOD

Amin et al, (6) 2014         69           AWOD

Amin et al, (6) 2014         53           AWOD
Amin et al, (6) 2014         53           AWOD

Amin et al, (6) 2014         47           DOC
Amin et al, (6) 2014         39           AWOD
Amin et al, (6) 2014         31           AWOD
Amin et al, (6) 2014         11           AWOD
Amin et al, (6) 2014         1            AWOD
Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA

Amin et al, (6) 2014         NA           NA

Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA

Amin et al, (6) 2014         NA           NA

Amin et al, (6) 2014         NA           NA
Amin et al, (6) 2014         NA           NA

Amin et al, (6) 2014         NA           NA
Pasternak et al, (21) 2014   NA           NA

Prakash et al, (22) 2014     6            AWOD

Chahal et al, (18) 2015      NA           NA

Wang et al, (26) 2016        NA           NA

Abbreviations: AWOD: alive without disease; DOC, dead
of other causes; NA, not available.
COPYRIGHT 2019 College of American Pathologists
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2019 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Wang, Diping; Sule, Norbert
Publication:Archives of Pathology & Laboratory Medicine
Article Type:Report
Date:Feb 1, 2019
Words:4467
Previous Article:A Pathologist's Guide to Creating an Informative Report and Improving Patient Care.
Next Article:Calcifying Nested Stromal-Epithelial Tumor of the Liver: An Update and Literature Review.
Topics:

Terms of use | Privacy policy | Copyright © 2020 Farlex, Inc. | Feedback | For webmasters