urachal carcinoma of the non-glandular type
Friday 23 March 2012
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.
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