Extrapelvic Uterus-like Masses Presenting as Colonic Submucosal Tumor: A Case Study and Review of Literature
A 39-year-old woman was admitted to the gynecology department for continuous abdominal pain in the right lower quadrant and which radiated to the right thigh. She denied dyspepsia or bowel habit changes. Her medical history was remarkable for chronic abdominal pain and ovarian endometriosis two years ago, which were managed by total hysterectomy and left salpingo-oophorectomy. Physical examination revealed mild tenderness on the suprapubic area and right lower quadrant. Laboratory data included a white blood cell count of 6,200/mm3, a hemoglobin concentration of 7.8 g/dL, and a platelet count of 397,000/mm3. The work-up for anemia revealed serum iron of 59 µg/dL, total iron-biding capacity of 454 µg/dL, serum ferritin of 70 ng/mL, and transferrin saturation of 12%, which were consistent with iron deficiency anemia. Pelvic ultrasonography revealed a 6×4 cm-sized multilocular cystic mass in the right adnexa. Ovarian endometriosis was suspected, and laparoscopic right salpingo-oophorectomy was performed. The histologic diagnosis was a hemorrhagic corpus luteum. Despite the surgery, her symptoms persisted. Considering the possibility of gastrointestinal bleeding, colonoscopy was performed. Colonoscopy demonstrated a protruding, firm submucosal mass at the appendiceal orifice of the cecum that was covered by intact mucosa (). In addition, another lesion suggestive of an extrinsic compression rather than a broad based submucosal tumor was noted in the descending colon (). Contrast-enhanced computed tomography of the abdomen and pelvis showed a small luminal protruding mass with enhancement in the medial wall of the cecum and another lobulating mass with contrast enhancement that contained a small internal area of low attenuation in the descending colon (). The latter lesion was located both inside and outside of the colon and appeared dumbbell-like in shape. In addition, another small enhancing mass containing an area of low attenuation was observed in the descending mesocolon (). Tumor marker levels, including alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 19-9, were within normal ranges. With a presumptive diagnosis of gastrointestinal stromal tumor or intestinal endometriosis, laparoscopic exploration was performed, and the three masses were resected by cecectomy and left hemicolectomy.\nGrossly, the cut surfaces of these masses showed a central cavity containing serosanguinous fluid, lined by a thick, soft, tan-yellow leiomyomatous wall. Histologically, the central cavity was lined by endometrial glands and stroma, which were surrounded by smooth muscles. In addition, small endometrial glands and stroma were scattered within the masses (). On immunostaining, the endometrial glandular cells within the masses were positive for estrogen receptor (ER; 1:25, Novocastra, Newcastle upon Tyne, UK) and progesterone receptor (PR; 1:200, Novacastra). The endometrial stromal cells were positive for ER, PR, and CD10 (1:500, Novacastra) and focally positive for smooth muscle actin (SMA; 1:4,000, Dako, Glostrup, Denmark). The smooth muscle cells of the masses were positive for ER, PR, and SMA and focally positive for CD10. Colonic smooth muscles adjacent to the masses were negative for ER, PR, and CD10 (). These findings were consistent with a previously-reported case of ULM.\nThe patient was discharged two weeks after surgery without postoperative complication. On follow-up, she reported no pain or shown evidence of anemia for 15 months.