Sigmoid cancer mimicking ovarian echotexture on transvaginal ultrasound: Case report with literature review

Ultrasound is a first line imaging modality for the evaluation of female pelvic pain. Pelvic pain constitutes one of the most common reasons for presentation to the emergency department with increasing use of point of care ultrasound. Infrequently, point of care or formal ultrasound evaluation may lead to misdiagnosis of extraovarian disease. This can have serious consequences, especially if an extraovarian malignancy is mistaken for a normal ovary or an ovary with a benign process. We present a case of a 41-year-old female who presented to the emergency department for a chief complaint of pelvic pain and vaginal bleeding. Transvaginal ultrasound demonstrated a left adnexal mass, later characterized as a sigmoid colon cancer on MRI and pathology, simulating ovarian echotexture with peripheral hypoechoic components resembling follicles. This article will review the literature of various cases of extraovarian pathology misidentified as ovarian processes and highlight the importance of considering these extraovarian mimickers to prevent potential morbidity and mortality of a missed diagnosis.