Gastroesophageal Junction Adenocarcinoma With Skeletal Muscle Metastases: A Case Report and Literature Review

Esophageal and gastroesophageal junction (GEJ) malignancies are aggressive, and survival is poor once metastasis occurs. The most common sites of metastatic involvement include the liver, lymph nodes, lung, peritoneum, adrenal glands, bone, and brain, while skeletal muscle (SM) involvement is rare. We report a case of a 68-year-old female who presented with intractable emesis for one month and was found to have a primary GEJ adenocarcinoma measuring up to 6.7 cm. Endoscopic biopsy revealed poorly differentiated GEJ adenocarcinoma with positive AE1/AE3 immunostains. Positron emission tomography/computed tomography and magnetic resonance imaging revealed metastases to the omentum and left lower extremity SMs, including the proximal adductor longus, adductor magnus, and gluteus minimus. This study reviews the literature on SM metastasis in esophageal and GEJ cancer, GEJ cancer classification, incidence, treatment, and prognosis.