Squamous Cell Carcinoma Arising From a Renal Calyceal Diverticulum

Area of Science:

• Urology
• Oncology
• Pathology

Background:

• Calyceal diverticulum is a renal collecting system outpouching lined by transitional epithelium.
• Tumorigenesis within calyceal diverticula is exceptionally rare.
• Primary squamous cell carcinoma in this location has not been previously documented.

Observation:

• A case presented with a lesion initially appearing as a benign cystic mass on imaging.
• The lesion was identified as a primary squamous cell carcinoma arising from a calyceal diverticulum.

Findings:

• This is the first reported instance of primary squamous cell carcinoma originating from a calyceal diverticulum.
• The tumor's initial presentation mimicked a benign cystic lesion, posing a diagnostic challenge.

Implications:

• Highlights the importance of considering rare malignancies in calyceal diverticula, even with benign imaging features.
• Suggests that calyceal diverticula, though rare, can be a site for primary squamous cell carcinoma development.
• Emphasizes the need for thorough histopathological evaluation of calyceal diverticular lesions.