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

Abstract

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.

Neuroendocrine Neoplasms of the Gynecologic Tract

“…Ovarian carcinoids can be a primary or metastatic tumor. Primary ovarian carcinoids (POC) are more common than metastatic tumors, constituting 0.1% of the ovarian neoplasms [ 89 ]. Most POC manifest as a small, lobulated, solid, and unilateral soft tissue lesion in a dermoid cyst.…”

Neuroendocrine Neoplasms of the Female Genitourinary Tract: A Comprehensive Overview

“…It is asymptomatic and incidentally detected in 25-30% of patients [6,9]. Typical symptoms of the carcinoid syndrome, including flushing, edema, and diarrhea, are uncommon and are seen in <10-15% of patients [5,[10][11][12]. The incidence of small-cell renal NEC is rare; approximately 50 cases have been reported in the literature [13][14][15][16][17].…”

“…Ultrasound of renal NENs shows an iso-to hyperechoic mass with a peripheral anechoic or hypoechoic rim [11,12,44]. Computed tomography demonstrates a well-circumscribed solid, hypodense tumor with minimal enhancement in contrastenhanced venous phase CT that corresponds to hypo-or avascular lesions on angiography (Figures 3-5) [18,45].…”

“…Heterogeneity and calcifications on CT can be seen in 60% and 26% of cases [9,33]. Around 75% of patients present with tumors > 4 cm, and >50% of patients demonstrate extrarenal invasion (perinephric, renal vein, or renal sinus fat) or distant spread of tumor [12,46]. However, differentiation is challenging, solely based on CT or MR imaging findings among renal NENs and renal cell carcinoma (Table 2).…”

The Colorful Palette of Neuroendocrine Neoplasms in the Genitourinary Tract

“…There is no gender predilection. The mean age of the patients was 49 years, and approximately 25-50% of the cases were discovered accidentally, and the remaining patients presented with symptoms similar to the ones caused by renal cell carcinoma (RCC), such as pain in the pelvic region, weight loss, fever, palpable mass, and hematuria (3). Carcinoid syndrome is infrequent, and it is presented only in 10-15% of patients with the following symptoms: flush, diarrhea, and generalized edema (9).…”