Small cell carcinoma of the uterine corpus: MR imaging and pathological correlation.

Small cell carcinoma of the uterine corpus is a rare but aggressive neoplasm showing neuroendocrine differentiation; its radiological findings are not well described. We report the magnetic resonance features of 3 cases with pathological correlation. Small cell carcinoma is shown as a bulky endometrial tumor of heterogeneous appearance on T2-weighted images, frequently associated with diffuse myometrium invasion and early extrauterine spread. Irregular enhancement with multifocal unenhanced areas of the thickened myometrium on contrast-enhanced T1-weighted images may represent the infiltrative nature of the tumor with extensive necrosis.