Rectovaginal septum primary squamous cell cancer: Extremely rare entity

Rectovaginal septum primary cancer is an extremely rare entity including gastrointestinal stromal tumor , adenocarcinoma (endometriosis related/unrelated) and Mullerian cell remnant cancer. These cancers are usually asymptomatic, but can grow large enough to present with pelvic discomfort or pressure symptoms (urinary retention or constipation). Imaging plays an important role in detection, characterization, staging workup and follow-up. Despite adenocarcinoma being the histology seen in most cases of primary rectovaginal septum carcinoma, 1 prior case of squamous cell cancer was reported in 2016. To the best of our knowledge, our case is the second reported case of this same extremely rare entity. We discuss a 35-year female with a rectovaginal mass which was detected by pelvic ultrasound, worked up by computed tomography (CT), positron emission tomography-CT and diagnosed by large incisional transvaginal biopsy. The patient underwent combined chemoradiotherapy, which resulted in complete resolution of the mass on follow up pelvic magnetic resonance imaging. Standard management guidelines are not available due to lack of adequate data.