CASE OF THE MONTH

Large Cell Neuroendocrine Carcinoma of the Bladder


The patient is a 67 year old gentleman who presented with macroscopic hematuria. Cystoscopy revealed a large, friable bladder tumor that occupied the entire left wall of the bladder. Transurethral resection showed a high grade malignant neoplasm consisting of large, uniform cells with scant cytoplasm. The nuclei contained fine, evenly distributed chromatin. Nucleoli were not obvious. Abundant apoptotic (necrotic) debris was present. Mitotic figures were numerous (99 per 10 HPFs). The morphologic features are that of a large cell neuroendocrine carcinoma.

Immunoperoxidase stains showed that the tumor was positive for cytokeratin 8/18 (Cam 5.2), chromogranin, and synaptophysin.



This phenotype supports the established diagnosis. Neuroendocrine carcinomas of the urinary bladder are relatively rare, accounting for less than 1% of all bladder carcinomas. These tumors are divided into the more indolent (typical or atypical) carcinoid tumors and the aggressive (small and large cell) neuroendocrine carcinomas. Large cell carcinoma of the bladder is an aggressive tumor that usually presents in an advanced stage. Neoadjuvant chemotherapy with a platinum regimen plus aggressive surgical approach is the usual treatment of choice.



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