Splenic sarcoid reaction mimicking metachronous metastasis in patients after distal gastrectomy for gastric cancer: a case report and literature review

BACKGROUND: The occurrence of sarcoid reactions has been recognized in various cancers. The common location for observing these granulomas is mainly the lymph nodes, but a rare occurrence in the spleen has been reported. Almost all splenic sarcoid reactions associated with gastric cancer have been resected synchronously and diagnosed accidentally, and a rare metachronous occurrence of a sarcoid reaction in the spleen after distal gastrectomy can mimic cancer metastasis. We describe a rare case of a splenic sarcoid reaction recognized in a patient with gastric cancer 6 months after distal gastrectomy. CASE PRESENTATION: An 82-year-old man underwent laparoscopic distal gastrectomy for gastric cancer (T3N0M0, stage IIA). Six months after gastrectomy, CT and 18F-fluorodeoxyglucose (FDG)-PET/CT showed the appearance of a splenic mass. We diagnosed solitary splenic metastasis from gastric cancer and performed laparoscopic-assisted splenectomy. His splenic tumor was diagnosed as a sarcoid reaction by histopathological examination. CONCLUSION: To our knowledge, this is the first report of a splenic sarcoid reaction recognized 6 months after distal gastrectomy for gastric cancer without any chemotherapy. The splenic sarcoid reaction and cancer metastasis to the spleen were undistinguishable from the CT and FDG-PET/CT findings. The present case and literature review showed that cases of splenic sarcoid reactions associated with gastric cancer can also be accompanied by the occurrence of these granulomas in lymph nodes. When the appearance of a solitary mass is observed in the spleen after resection of primary cancer, it is necessary to consider not only cancer metastasis but also sarcoid reactions. Retrospective histopathological confirmation of the existence of sarcoid reactions in lymph nodes from resected specimens might possibly avoid incorrect diagnosis and intervention.