Uterine large cell neuroendocrine carcinoma with unusual colonic metastasis.

A 78-year-old female patient arrived at our practice complaining of progressive abdominal increase and presenting a clinical picture of intestinal obstruction. At physical examination, the abdomen appeared distended, moderately painful with the presence of a mass of hard consistency. Abdominal computed tomography scan showed a large hypodense pelvic mass that indicated a compression and lateral deviation of the uterus and bladder. Microscopically, the mass showed a uniform solid pattern, composed of medium and large-sized cells with hyperchromatic and pleomorphic nuclei demonstrating high mitotic activity and diffuse immunoreactivity for estrogen receptors and synaptophysin. A diagnosis of uterine poorly differentiated large cell neuroendocrine carcinoma, arising in the endometrium with an unusual colonic metastatic localization, was made.