Laparoscopic resection of a primary diaphragmatic schwannoma: a case report and literature review

BACKGROUND: Schwannomas are nerve sheath tumors that commonly originate from the stomach and small intestine. A primary schwannoma of the diaphragm is rare and does not show any symptoms until it grows to a certain size. Hence, it is extremely rare that it was found at a size that allowed resection under videoscopic surgery. CASE PRESENTATION: A 77-year-old woman was referred to our department for surgical treatment of a tumor located near the gastric fornix. She underwent a routine esophagogastroduodenoscopy 2 years and 7 months prior to the referral. It was suspected that she had a submucosal tumor measuring 10 mm, located in the fornix, and was then referred to her previous physician. During her follow-up, endoscopic ultrasonography (EUS) revealed that the cystic structure had continued to grow toward the gastric wall, and she was then referred to the endoscopy division of our hospital. She continued to be followed-up, and it was noted that the tumor was gradually increasing in size. Therefore, she requested surgical resection, and was finally referred to our division. Since the tumor was rather small, we planned a laparoscopic surgery. An initial examination during the operation revealed that the tumor was located on the left diaphragm. Since the tumor was relatively small and visibility was good, we decided to continue with the laparoscopic surgery. Partial diaphragmectomy with complete inclusion of the tumor was performed, and the defect of the diaphragm was directly closed by a running suture. Pathological examination revealed a benign schwannoma that had originated from the diaphragm. To support our findings, we also reviewed the scientific literature on diaphragmatic schwannoma cases reported up to April 2020. CONCLUSIONS: In this extremely rare case, we successfully resected the diaphragmatic schwannoma using laparoscopic surgery.