Disseminated Peritoneal Leiomyomatosis and Metastatic GIST: Differential Diagnosis Dilemma Regarding Multiple Nodular Serosal Lesions and Management

Aim: We aim to discuss cases with gastrointestinal stromal tumor and leiomatosis peritoneal dissemeniata LPD regarding their diagnosis and surgical management with pitfalls related. We also aim to focus on management of multiple nodular serosal lesions. Method: Two cases are presented. Both were diagnosed as advanced ovarian cancer on CT and ultrasound imaging by multiple nodular peritoneal lesions, omental cake and adnexal masses. Tumor markers were normal in both cases. Both were scheduled for exploratory laparotomy. One patient diagnosed with neurofibromatosis type I. Results: Midline laparotomy was done for one case revealing normal adnexa with multiple fibroid uterus, peritoneal solid masses with large mesenteric and omental masses related to the small intestine. Total hysterectomy with bilateral salpingo-oophorectomy, total omentectomy and resection anastomosis for the small intestine with removal of macroscopic lesions were done. Midline line laparotomy was done for the second case revealing free adnexa with subserous vascular fibroids and omental fibroid solid masses. Total hysterectomy with bilateral salpingo-oophorectomy and total omentectomy and removal of macroscopic peritoneal lesions seen were done. The second case was diagnosed as Disseminated Peritoneal Leiomyomatosis, and the other case was diagnosed with multiple uterine fibroid and metastatic GIST on histopathology. Conclusion: Disseminated Peritoneal Leiomyomatosis and metastatic GIST can be similar on imaging and operative findings. Also they are similar to other lesions especially peritoneal carcinomatosis as in advanced ovarian cancer. These pathologies should be kept on mind when encountering multiple solid nodular masses in the visceral and parietal wall peritoneum and the omentum on imaging and intra-operative especially with normal associated tumor markers of ovarian cancer as serum CA125. Surgical and postoperative management differ according to the pathology. These pathologies should be confirmed by histopathology and immunohistochemistry. Frozen section is highly needed in these cases to optimize management. © 2018, Association of Gynecologic Oncologists of India.