Extragastrointestinal stromal tumor mimicking a uterine tumor. A rare clinical entity

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. These tumors are present in almost all case mutations of KIT-CD117. When located in different places other than the gastrointestinal tract they are called extragastrointestinal stromal tumors (EGISTs). We present the case of a 70-year old patient with abdominal pain. Computed tomography (C/T) and ultrasound (U/S) indicated the existence of a hypoechoic enlarged 9.6 x 10 cm uterus due to leiomyoma. The clinical condition of the patient deteriorated and obtained the characteristics of an acute abdomen. The patient underwent urgent exploratory laparotomy, which revealed the incidental existence of a large tumorous formation in the pouch of Douglas. A total abdominal hysterectomy, bilateral ovarectomy, omentectomy, and tumor resection from the rectouterine pouch were performed. Histology analysis confirmed the diagnosis of a malignant EGIST. EGISTs are infrequent in pelvis. In our case, pelvic EGIST led to an acute pain symptomatology obtaining characteristics of invasive uterine leiomyosarcoma. Pelvic imaging with classical methods of U/S and C/T may lead to confusion and false diagnosis. To the best of our knowledge, this is the first case report about an EGIST located in the rectouterine pouch of Douglas leading to acute abdomen symptomatology.