Metastatic Gastric Signet Ring Cell Adenocarcinoma Masquerading as Low Back Pain.

This case report describes a 53-year-old Hispanic male who initially presented with acute hip pain. During workup, sclerotic bone lesions of the lumbar spine were identified on computed tomography (CT) in addition to extensive adenopathy involving the chest and abdomen. Upper endoscopy revealed chronic active gastritis, however, biopsies were negative for malignancy. Eventual bone marrow biopsy showed extensive infiltration by sheets of malignant epithelial cells with signet ring cell formation. Not only is this case significant for maintaining a broad differential in patients presenting with bone pain, but it also demonstrates a diagnosis of metastatic signet ring cell adenocarcinoma confirmed on bone marrow biopsy, which was not detected via earlier endoscopy.