Concurrent Findings of a GIST Tumor and Carcinoid Tumor in an Elderly Female

Abstract

Gastrointestinal stromal tumors (GIST) are sporadic growths that account for less than 1% of GI tumors. They are the most common group of mesenchymal neoplasms and can occur in any portion of the alimentary tract. Carcinoid tumors are relatively rare tumors that are well-differentiated neuroendocrine growths, the majority of which arise in the GI tract. Both GIST and carcinoid tumors are potentially malignant and the pathogenesis of concurrent findings in a patient remains unclear. We are presenting a rare case of a patient who had concomitant findings of a GIST and carcinoid tumor. A 70-year-old woman presented with 2 months of progressively worsening abdominal pain associated with early satiety. She also noted increasing abdominal fullness over a period of 2 years. Physical exam revealed a distended abdomen with a lower abdominal central mass that was palpable up to the umbilicus with moderate tenderness to palpation. CT scan of the abdomen and pelvis revealed a large irregular enhancing mass within the pelvis which extended into the lower abdomen, measuring approximately 14.0 x 14.0 x 15.0 cm which may be arising from the right adnexa and was suspicious for a large heterogeneous ovarian mass. A portion of the mass appeared to erode into the wall of the adjacent cecum. MRI of the pelvis revealed mostly necrosis and blood in the center of the mass with a circumferential ring of solid nodules. Colonoscopy and exploratory laparotomy were performed. Colonoscopy revealed 1 cm rectosigmoid polyp and a 2.5 cm ascending colon polyp that were not removed, and no erosion of the mass into the cecum. Laparotomy revealed a large mass originating from the small bowel and adherent to the sigmoid colon. Patient underwent small bowel resection with enterostomy, sigmoid resection with end-to-end anastomosis and bilateral salpingo-oophorectomy. Pathological analysis of the pelvic mass with immunohistochemical staining revealed GIST tumor. Analysis of tissue from the distal colon donut revealed a carcinoid tumor. The patient tolerated the procedure well and continues to follow up at the specialty clinics. Our case represents a rare finding of coexisting small bowel GIST and carcinoid tumor. To our knowledge, there has been only one reported case of a concomitant gastric GIST and carcinoid tumor. As few cases have been reported in literature, future studies may be used to evaluate a link between the occurrence of a GIST and carcinoid tumor in a single patient.Figure