Urachal mucinous neoplasms--to be or not to be: Two cases and a review of current diagnostic criteria (WHO 2016)

Abstract

The urachus is an embryological remnant that extends from the bladder to the umbilicus. Urachal neoplasms represent less than 1% of malignant bladder tumors. The new 2016 edition of disease classifications from the WHO has updated the classification of epithelial neoplasms of urachal origin, distinguishing between glandular and non-glandular neoplasms and between cystic and non-cystic adenocarcinomas. In this article, we present two cases with similar clinical presentations but differing histology. We address their morphological, immunohistochemical, and molecular characterization; review the classification and diagnostic criteria of glandular urachal neoplasms included in the most recent literature with the aim of clarifying their differential diagnosis as well as their prognostic implication; and, ultimately, better understand these infrequent biological entities.

Keywords

Urachus / Mucinous neoplasm / Urachal cyst / Adenocarcinoma / Immunohistochemistry / Molecular

ACKNOWLEDGEMENTS

Claire Alexandra Conrad provided language help and translation.

CONFLICTS OF INTEREST DISCLOSURE

No conflicts of interest.

References

[1] Hammong GYL, Davis JE. The urachus, its anatomy and associated fasciae. Anat Rec. 1941; 80: 271-87. https://doi.org/10.1002/ar.1090800302

[2] Schubert GE, Pavkovic MB, Bethke-Bedurftig BA. Tubular urachal remnants in adult bladders. J Urol. 1982; 127: 40-42. https://doi.org/10.1016/S0022-5347(17)53595-8

[3] Amin MB, Smith SC, Eble JN. Glandular neoplasm of the urachus:a report of 55 cases emphasizing mucinous cystic tumors with the proposed classification. Am J Surg Pathol. 2014; 38: 1033-1045. PMid:25025366. https://doi.org/10.1097/PAS.0000000000000250

[4] Paner GP, BarKan GA, Mehta V. Urachal carcinomas of the nonglandular type: salient features and considerations in pathologic diagnosis. Am J Surg Pathol. 2012; 36: 432-442. PMid:22301493. https://doi.org/10.1097/PAS.0b013e31823fe49c

[5] Paner GP, Lopez-Beltrán A, Sirohi D. Updates in the Pathologic diagnosis and classification of epithelial neoplasm of urachal origin. Adv Anat Pathol. 2016; 23: 71-83. PMid:26849813. https://doi.org/10.1097/PAP.0000000000000110

[6] Bruins J, VisserO, Ploeg M. The clinical epidemiology of urachal carcinoma: results of a large, population based study. J Urol. 2012; 188: 1102-1107. PMid:22901574. https://doi.org/10.1016/j.juro.2012.06.020

[7] Wright JL, Porter MP, Li CL. Differences in survival among patients with urachal and nonurachal adenocarcinomas of the bladder. Cancer. 2006; 107: 721-728. PMid:16826584. https://doi.org/10.1002/cncr.22059

[8] Hue and Jacquin. Cancer coloide de lómbilic et de la paroi abdominale anterieure ayant envahi la vessie. Union med. 1983; 6: 418.

[9] Ayala A, Tamboli P. Urachal carcinoma. In International Agency for Research on Cancer. Pathology and genetics of tumours of the urinary system and male genital organs. Lyon: IARC Press; 2004. 131 p.

[10] Zong L, Chen P. Surgical and chemotherapeutic experience regarding a urachal carcinoma with repeated relapse: case report and literature review. World Journal of Surgical Oncology. 2013; 11: 170-8. PMid:23914849. https://doi.org/10.1186/1477-7819-11-170

[11] Ojea A, Núñez A, Domínguez F. Adenocarcinoma mucinoso de uraco. Actas Urol Esp. 2003; 27(2): 142-146. https://doi.org/10.1016/S0210-4806(03)72892-7

[12] Murphy WM, Grignon DJ, Perlman EJ. Tumors of the kidney, bladder, and related urinary structures. AFIP atlas of tumor pathology. Series 4. Washington DC:ARP Press; 2008.

[13] Sheldon CA, Clayman RV, González R. Malignant urachal lesions. J Urol. 1984; 131: 1-8. https://doi.org/10.1016/S0022-5347(17)50167-6

[14] Wheeler JD, Hill WT. Adenocarcinoma involving the urinary bladder. Cancer. 1954; 7: 119-135. https://doi.org/10.1002/1097-0142(195401)7:1<119::AID-CNCR2820070113＞3.0.CO;2-8

[15] Johnson DE, Hodge GB, Abdul-Karim FW, et al. Urachal carcinoma. Urology. 1985; 26: 218-221. https://doi.org/10.1016/0090-4295(85) 90112-8

[16] Gopalan A, Sharp DS, Fine SW. Urachal carcinoma: a clinicopathologic analysis of 24 cases with outcome correlation. An J Surg Pathol. 2009; 33 (5): 659-68. PMid:19252435. https://doi.org/10.1097/PAS.0b013e31819aa4ae

[17] Dhillon J, Lian Y, Kamat AM. Urachal carcinoma: a pathologic and clinical study of 46 cases. Hum Pathol. 2015; 46: 1808-1814. PMid:26364859. https://doi.org/10.1016/j.humpath.2015.07.021

[18] Lopez-Beltran A, Paner G, Tsuzuki T. Urachal carcinoma. In International Agency for Research on Cancer. Pathology and genetics of tumours of the urinary system and male genital organs. Lyon: IARC Press; 2016. 113 p.

[19] Chen CY, Li MH, Tsai WM. Signet ring cell adenocarcinoma of the urachus:a case report and review of 28 cases. JTUA. 2006; 17: 103-8.

[20] Singh I, Prasad R. Primary urachal mucinous adenocarcinoma of the urinary bladder. Journal of Clinical and Diagnostic Research. 2013; 7(5): 911-13. PMid:23814741.

[21] Dadhania V, Czerniak B, Gui CC. Adenocarcinoma of the urinary bladder. Am J Clin Exp Urol. 2015; 3(2): 51-63. PMid:26309895.

[22] Hutchinson LPCG, Tomaszewicz K, Mehta K. KRAS is mutated in a subset of mucinous type urachal adenocarcinomas. Mod Pathol. 2012; 25: 214A.

[23] Sirantrapun SJ, Ward M, Woo J. High-stage urachal adenocarcinoma can be associated with microsatellite instability and KRAS mutations. Hum Pathol. 2014; 45: 327-330. PMid:24355196. https://doi.org/10.1016/j.humpath.2013.09.008