Multiple Muscle Metastases as the First Presentation of Gastric Cancer: A Case Report and Review of Literature.

The presence of an abdominal wall mass may serve as the initial presentation of an unknown gastric malignancy. The invasion of the abdominal wall and the occurrence of multiple skeletal muscle metastases originating from gastric cancer are exceedingly uncommon. We present a case of a 45-year-old female patient exhibiting widespread abdominal wall infiltration and skeletal muscle metastases derived from gastric cancer. The primary presentation included a distressing diffuse abdominal mass in the left upper and lower quadrants. Abdominal computed tomography revealed extensive swelling of multiple skeletal muscles within the abdominal wall, raising suspicions of gastric malignancy. Biopsies of the affected muscles, along with upper gastrointestinal tract endoscopy and colonoscopy, were performed. The upper endoscopy examination unveiled a poorly differentiated diffuse-type gastric adenocarcinoma, while the subsequent muscle biopsy confirmed infiltration by the recently diagnosed malignancy. At this stage of the disease, systemic chemotherapy was deemed the optimal choice for our patient. Subsequent abdominal computed tomography showed a decrease in the dimensions of the abdominal wall and other skeletal muscle lesions. Seventeen months after the initial diagnosis, our patient continues to be alive. Additionally, we provide a comprehensive review of the existing literature on similar reported cases of gastric cancer patients with concurrent muscle metastases.