Metachronous port site, muscular and subcutaneous metastases from a gastric adenocarcinoma: a case report and review of articles

BACKGROUND: Port site metastasis (PSM) after curative gastrectomy for gastric cancer and muscular metastasis from gastric cancer are rare manifestations. Similarly, subcutaneous metastasis from gastric cancer is rare, and muscular and subcutaneous metastases are associated with poor prognosis. We report a case of long-term survival in a patient who underwent curative resection of gastric cancer and repeated recurrence of port site, muscular and subcutaneous metastases from gastric cancer, treated by resection. CASE PRESENTATION: A 75-year-old man was diagnosed with gastric cancer and referred to our department. Upper endoscopy demonstrated a 5-cm circumferential ulcerated lesion at the cardia. Biopsy findings showed a poorly differentiated tubular adenocarcinoma. He underwent laparoscopic total gastrectomy with lymph node dissection, and pathologic examination revealed a moderately differentiated tubular adenocarcinoma stage T4aN1M0 and IIIA according to the UICC (Union for International Cancer Control) classification. He refused adjuvant chemotherapy and was only carefully observed. Twenty-three months after the primary gastrectomy, computed tomography (CT) revealed an irregular mass near the port site wounds. Then the patient underwent mass resection, and the pathological diagnosis was consistent with metastatic adenocarcinoma, located in the subcutaneous tissue at the port site wounds. Thirteen months after the second surgery, CT revealed an enhanced mass in the abdominal wall. Positron emission tomography (PET) CT showed an elevated uptake in the rectus abdominis muscle and a standardized uptake value (SUV) of 3.1. The patient underwent another mass resection, and the pathological diagnosis was consistent with metastatic adenocarcinoma in the rectus abdominis muscle. Thirty-five months after the third surgery, CT revealed a mass in the left gluteal subcutaneous region. Furthermore, PET-CT revealed a 35-mm mass with an elevated SUV of 9.6. Another mass resection procedure was performed, and the pathological diagnosis was consistent with metastatic adenocarcinoma in the subcutaneous tissue. Since tumor cells were present at the resection margin, additional radiation therapy was performed. The patient has survived 78 months after primary gastrectomy. CONCLUSION: The prognosis of muscular and subcutaneous metastases from gastric cancer is poor. However, if the metastatic tumor is solitary, surgical excision could be a feasible treatment option and might prolong survival.