Decades Later: Recurrent Gastrointestinal Sequelae in a Patient With Remote Metastatic Osteosarcoma to the Stomach and Colon.

Osteosarcoma is a primary malignant bone tumor with a well-established tendency for pulmonary metastasis; however, gastrointestinal (GI) involvement is exceedingly rare. Intra-abdominal metastases may occur years to decades after the initial diagnosis. Hematogenous spread, following pulmonary metastasis, is the presumed mechanism. Due to delayed presentation and atypical manifestations, recognition of GI complications in patients with a remote history of osteosarcoma is essential. In this report, we present a case of an 80-year-old male with chronic GI complications decades after original metastatic osteosarcoma diagnosis involving the stomach and colon. He described recurrent, dull, constant left lower quadrant abdominal pain associated with poor oral intake and constipation. Physical examination demonstrated focal left lower quadrant tenderness. CT abdomen and pelvis revealed dilated small bowel loops concerning for partial small bowel obstruction, while esophagram demonstrated esophageal dysmotility with mild reflux. These findings are linked to the sequelae of complications following initial metastatic osteosarcoma. The patient had a history of numerous surgeries and required continuous opioid use for pain management. Conservative management consisted of bowel rest, laxatives, and supportive care resulting in transient symptom improvement; however, symptoms recurred frequently following discharge, leading to multiple readmissions for recurrent obstructive and dysmotility-related symptoms. This case highlights several gastroenterological considerations. Metastatic osteosarcoma and further GI sequelae should remain within the differential diagnoses of chronic abdominal pain or bowel obstruction in patients with a remote history of osteosarcoma, even decades after initial treatment. For gastroenterologists, recognition of both structural and functional GI sequelae of osteosarcoma is critical to guide symptom-directed, nonoperative management strategies and reduce recurrent hospitalizations.