Neuroendocrine neoplasms of the genitourinary tract in adults: cross-sectional imaging spectrum

Neuroendocrine (NE) neoplasms of the genitourinary (GU) tract in adults are rare tumors with distinct histopathology and variable biological behavior and imaging findings. They may be primary or metastatic in origin. The spectrum of primary GU tract NE neoplasms includes carcinoid, small cell carcinoma, large cell NE carcinoma, and paraganglioma. The tumors commonly show positivity to specific immunohistochemical markers and characteristic dense-core granules at the ultra-structural level. Although imaging findings are nonspecific and accurate differentiation from the more common malignancies of the individual organs is not possible, cross-sectional imaging modalities play an important role in the diagnosis, staging, and surveillance of these tumors. Somatostatin receptor scintigraphy (octreotide scan) may be useful in the detection and treatment of metastatic disease in select patients. Knowledge of the various NE tumors of the adult GU tract and familiarity with their pathological and imaging findings permit optimal patient management.