[A Case of Recurrent Gastric GIST Who Survived for Long after Laparoscopic Resection and Imatinib Therapy].

A man patient in his 70s underwent left nephrectomy and laparoscopic partial gastrectomy for the treatment of a left renal cell carcinoma and gastrointestinal stromal tumor(GIST)arising from the stomach. Histopathologically, both the renal cell carcinoma and GIST were kit-positive, CD34-positive, and S-100 protein-negative, and the Ki-67 index was about 40% as determined by the hot spot method, so that it was diagnosed as an intermediate-group GIST. After surgery, the patient was followed without adjuvant therapy, as he did not wish to receive postoperative chemotherapy. A computed tomography(CT)conducted 3 years after the surgery revealed tumorous shadows in the abdominal wall, inferior periesophageal region, and dorsal aspect of the pancreas. Positron emission tomography(PET)-CT showed fluorodeoxyglucose(FDG) accumulation in these lesions. Therefore, based on a suspicion of recurrent renal cell carcinoma or GIST, we carried out abdominal wall tumor resection for both exploratory and diagnostic purposes, which yielded histopathological diagnosis of GIST, with features similar to those observed at the time of the initial operation. Because the number of tumors remained unchanged during the subsequent follow-up period, the tumorous lesions in the periesophageal region and on the dorsal aspect of the pancreas were resected laparoscopically. Each of the resected tumors showed histological features consistent with GIST. The patient was started on oral imatinib therapy after this operation. To date(5 years after the surgery for the recurrent tumors and 8 years after the initial operation), the patient has remained free of recurrence. The pattern of tumor recurrence noted in the present case(ie, metastasis/dissemination to the skeletal muscles)is relatively rare, and few reports have been published concerning long-term survivors through multidisciplinary treatment (surgical treatment and others). We report this case with a review of the literature.

[A Case of Unresectable Advanced Gastric Cancer Successfully Treated with Conversion Surgery].

A man in his 70s consulted a local clinic with a chief complaint of difficulty eating. Upper gastrointestinal endoscopy revealed a type 4 tumor spreading irregularly from immediately below the esophageal cardia to the lower gastric body. The patient was referred to our hospital with a diagnosis of advanced gastric cancer(human epidermal growth factor receptor 2 [HER2]-positive moderately-differentiated adenocarcinoma)accompanied by lymph node enlargement. We planned an open total gastrectomy after staging laparoscopy to rule out dissemination because peritoneal dissemination could not be ruled out using computed tomography(CT). To perform a total gastrectomy, a celiotomy was done after staging laparoscopy results suggested that dissemination was unlikely. However, the border between the pericardial lymph nodes and the pancreas or peritoneal artery was not visible, forcing us to terminate the staging laparotomy based on a judgment of unresectable locally advanced gastric cancer. Therefore, the patient was administered 6 cycles of combined S-1/CDDP plus trastuzumab as the primary therapy. The response to therapy was favorable, and we scheduled a surgical resection. However, the scheduled surgery was rescheduled because of COVID-19 pneumonia, and R0 resection was finally performed after the 7th cycle of S-1/CDDP plus trastuzumab therapy. Histopathologically, the regional lymph node metastasis had disappeared, the viable tumor remained within the mucosal layer, and scarring was evident from the submucosal layer to the serosa. In recent years, conversion surgery for unresectable gastric cancer has been sporadically reported. However, we are unable to definitively opine on whether this kind of surgery may contribute to improving the prognosis, resection remains indispensable for radical treatment. We report this case along with a review of the literature.