8th Euro Global Summit on Cancer Therapy
University of the Philippines, Philippines
Title: Efficacy of imatinib in an extra-gastrointestinal stromal tumor presenting as a unilateral ovarian mass
Biography: Ann Meredith Uao Garcia
We present the case of a 58-year-old female with a 6-month history of abdominal enlargement. She had previous bowel surgery for an undocumented diagnosis 20 years prior. CT scan showed a pelvic mass. Intraoperatively, the right adnexa was converted into a large, encapsulated, cystic mass with areas of necrosis and hemorrhage. Adherent segments of the ileum and omentum were resected with no masses or gross tumor implants. Histopathologic diagnosis was low-grade fi brosarcoma of the right ovary, with both ileum and omentum positive for tumor. Immunostaining with CD117 (+) and S-100 (-) were done. Subsequent work-up showed hepatic nodules. A diagnosis of gastrointestinal stromal tumor (GIST) was made and imatinib mesylate was started with good clinical response. Preoperative diagnosis of GISTs is uncommon due to its rarity and varied manifestations, more so if it presents as an ovarian mass, an extremely rare event. Routine imaging studies cannot diff erentiate extra-gastrointestinal stromal tumors (eGISTs) from ovarian cancer, so the diagnosis rests on histology and immunohistochemistry. Th e signifi cance of the patient’s previous intestinal pathology in relation to the present tumor cannot be reliably discerned, but the treatment is similar for both recurrent and metastatic cases, whether this is a primary ileal or ovarian GIST. Surgery is the mainstay of treatment and correct postoperative diagnosis is crucial as misdiagnosis carries signifi cant therapeutic and prognostic implications because of the ineff ectiveness of standard chemotherapy and radiotherapy. Th e oral tyrosine kinase inhibitor, imatinib mesylate, has been demonstrated to be an eff ective treatment for both GISTs and eGISTs.