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urachal carcinomas

Wednesday 6 May 2009

Urachal carcinomas occur mostly in the bladder dome, comprising 22% to 35% of vesical adenocarcinomas, and are generally treated by partial cystectomy with en bloc resection of the median umbilical ligament and umbilicus. Detailed pathologic studies with clinical outcome correlation are few.

Pathologic stage is an important prognostic factor in urachal carcinoma. Surface urothelial involvement by carcinoma and presence of cystitis cystica/glandularis do not necessarily exclude the diagnosis of urachal carcinoma.

Immunostains do not unequivocally discriminate a urachal from a colorectal carcinoma, but diffuse positivity for 34BE12 would support, and diffuse nuclear immunoreactivity for beta-catenin would militate against, a diagnosis of urachal carcinoma.

Local recurrence may be owing to seeding within the distal urothelial tract, particularly in tumors with a configuration that is polypoid and which open into the bladder cavity.

The type of surgery performed may have an effect on local recurrence despite negative margins of resection.

Urachal Carcinomas of the Nonglandular type

The vast majority of malignant urachal epithelial tumors have a glandular morphology (ie, adenocarcinoma), to which our principal understanding of urachal carcinoma and its prevailing set of diagnostic criteria are largely ascribed.

The 2004 World Health Organization classification of genitourinary tumors recognizes other rarer histologic types of urachal carcinomas such as urothelial, squamous cell, and other carcinomas.

Non-glandular urachal carcinoma may occur with pure histology or admixed with high-grade dedifferentiated morphologies and a minor adenocarcinoma component.

These tumors may arise as deep-seated bladder-related or completely supravesical tumors along the urachal tract and may exhibit reverse invasive spread toward the bladder surface.

Cavitary or luminal growth may occur that could be attributed to the intraurachal neoplastic proliferation.

Urachal urothelial carcinomas in particular may contain papillary structures within the tumor and urachal cavity.

Concomitant primary urothelial carcinoma outside of the urachus and tumor extension to bladder mucosa may occur, which should not negate diagnosis of an urachal primary. Behavior appears poor, as most tumors present with higher stage.

See also

- urachal adenocarcinoma

References

- Urachal Carcinomas of the Nonglandular type: Salient Features and Considerations in Pathologic Diagnosis. Paner GP, Barkan GA, Mehta V, Sirintrapun SJ, Tsuzuki T, Sebo TJ, Jimenez RE. Am J Surg Pathol. 2012 Mar;36(3):432-42.PMID: 22301493

- Urachal carcinoma: a clinicopathologic analysis of 24 cases with outcome correlation. Gopalan A, Sharp DS, Fine SW, Tickoo SK, Herr HW, Reuter VE, Olgac S. Am J Surg Pathol. 2009 May;33(5):659-68. PMID: 19252435