October 2019
INTRODUCTION: We present a case of primary endometrioid adenocarcinoma with invasion of the rectosigmoid colon, highlighting the importance of colonoscopy, biopsy, cross-sectional imaging, and a multidisciplinary approach to the management of extraluminal lesions.
CASE DESCRIPTION/METHODS: A 47-year-old female with a history of lymphangioleiomyomatosis (LAM) was admitted for abdominal pain, hematochezia, tenesmus, and proctalgia following 7 months of abnormal bowel habits and 20 pounds of unintentional weight loss. Review of symptoms was negative for abnormal uterine bleeding. Examination revealed tenderness on palpation of the lower abdominal quadrants, and grossly bloody stool with digital rectal exam. Computed tomography (CT) of the abdomen and pelvis with contrast demonstrated circumferential rectal wall thickening with enhancement. Colonoscopy revealed an ulcerated extraluminal rectosigmoid mass, and biopsies were obtained. Magnetic resonance imaging (MRI) demonstrated a large heterogeneous mass involving the uterus and rectum with no discernable fascial plane. Initial pathology reported invasive adenocarcinoma without a primary origin delineated. A multidisciplinary conference prompted additional immunostaining of the sample, confirming endometrioid adenocarcinoma. The patient was diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage IVa endometrioid adenocarcinoma and underwent surgical management with adjuvant chemoradiation.Genetic testing demonstrated heterozygosity with a pathologic variant in the MutL homolog 1 (MLH1) gene consistent with Lynch Syndrome. Surveillance positron emission tomography scanning 6 months later revealed no evidence of disease recurrence.