Neuroendocrine carcinoma of the urinary bladder: a retrospective study of CT findings

The purpose of this study was to evaluate the radiographic features of neuroendocrine carcinoma of the urinary bladder (NECB) on CT and to review the literature regarding carcinogenesis, treatment, and prognosis. The presenting CT of patients with pathology-proven NECB were retrospectively reviewed for features including size and appearance of the bladder mass, the presence of hydronephrosis, bladder wall thickening, invasion of perivesical fat, lymph nodes, and distant metastasis. Follow-up imaging and the medical record were reviewed to determine patient treatment and overall survival. Sixteen patients (13 males, 3 females) were diagnosed with NECB with a mean age of 75.5 years (range 48-90). The characteristic CT appearance was a large polypoid bladder mass (average size 4.9 cm). Extension into the perivesical fat, adjacent organ involvement, and distant metastases were common. NECB is an aggressive primary neoplasm of the bladder that presents on CT as a large bladder mass with local extension into the perivesical fat, involvement of adjacent organs, and metastasis.