Primary Urachal Squamous Cell Carcinoma: A Case Report.

The urachus is a tubular vestigial remnant extending from the anterior dome of the bladder to the umbilicus. Carcinoma arising from it is uncommon but aggressive. Primary urachal carcinoma, an epithelial neoplasm, is one such abnormality which is rare and aggressive accounting for a very small portion of all bladder cancers. We herein present a case of a 48-year-old woman admitted with complaints of abdominal pain and abdominal mass. The mass was fixed to the anterior abdominal wall. A radiological investigation revealed a mass involving the midline of the anterior abdominal wall in the infraumbilical region with irregular margins along the course of the urachal ligament with surrounding fat stranding, suggesting a possibility of urachal malignancy with local extension. An ultrasound-guided core needle biopsy showed squamous cell carcinoma. The tumor was removed surgically. Further histological examination showed primary moderately differentiated squamous cell carcinoma of the urachus with metastasis to regional lymph nodes, extending into anterior abdominal muscles and up to the mucosa of the ileum. These findings correspond to the stage IVA of the Sheldon staging system for urachal carcinoma. Due to the rarity of urachal squamous cell carcinoma and limited research, definitive treatment guidelines are lacking. Current recommendations are based on small case series and lack a standardized staging system. Surgical intervention remains the cornerstone of treatment, often encompassing complete resection of the urachus, umbilicus, adjacent involved tissue with free margins, and potentially the bladder or regional lymph nodes to mitigate the risk of metastasis and local recurrence.