Gone to Guts: Osteosarcoma With Metastasis to Small and Large Intestines Presenting as Recurrent Bleeding.

Gastrointestinal involvement in osteosarcoma is uncommon, with colonic spread being particularly rare. Symptoms range from abdominal pain and obstruction to anemia and melena. Chemotherapy for metastatic lesions has not been standardized, and surgery remains the treatment for selective candidates. We describe a rare occurrence of osteosarcoma metastasizing simultaneously to the small and large intestines in a 43-year-old man who presented with recurrent gastrointestinal bleeding causing symptomatic anemia. Endoscopic examination revealed multiple nodules in the jejunum and colon consistent with metastatic osteosarcoma.

Liposarcoma Masquerading as Immunoglobulin G4-Related Disease.

This case report highlights the challenge of differentiating between immunoglobulin G4 (IgG4)-related disease (IGRD) and liposarcoma, which have similar symptoms and serological markers. A 40-year-old woman presented with right upper-quadrant pain and a retroperitoneal mass. Initial biopsy indicated increased IgG4-positive cells, leading to an IGRD diagnosis. However, the mass grew, despite prednisone treatment, prompting a repeat biopsy that revealed well-differentiated liposarcoma. Liposarcoma should be considered in patients with retroperitoneal masses and elevated IgG4 levels. Surgical resection is the primary treatment, emphasizing the need for early identification and close monitoring. Confirming IGRD or ruling out other diagnoses through histopathologic analysis is vital.