Metachronous skeletal muscle metastasis without any other organ metastases after curative gastrectomy: a case report

BACKGROUND: Skeletal muscle metastasis from gastric cancer is extremely rare and often accompanied with synchronous metastasis to any other organs. We herein report a case of rapidly developing multiple skeletal metastases from gastric cancer without any other organ metastases. CASE PRESENTATION: A 47-year-old man underwent distal gastrectomy for advanced gastric cancer. Pathological diagnosis was poorly differentiated adenocarcinoma, T2N1M0, Stage IIA. The patient presented with a history of left dorsal tenderness 12 months after the operation. A computed tomography (CT) revealed a solid mass in the left latissimus dorsi muscle. Pathological examination of the ultrasound guided needle biopsy specimen revealed poorly differentiated adenocarcinoma similar to the previously resected gastric cancer, and the tumor was diagnosed as metastasis of gastric cancer. Thereafter, the systemic chemotherapy was administrated. However, the metastases were extended to the paraspinal muscle and quadriceps, and the patient died 7 months after the recurrence. CONCLUSIONS: The prognosis of patients with skeletal muscle metastasis may be extremely poor, even in patients without any other organ metastases. The development of further chemotherapeutic agents and regimens is therefore needed.