Extraskeletal Osteosarcoma of the Omentum with Aggressive Development

Area of Science:

• Oncology
• Pathology

Background:

• Extraskeletal osteosarcomas (ESOS) are rare malignant neoplasms, constituting approximately 4% of all osteosarcomas and 1.2% of soft-tissue sarcomas.
• Fewer than 300 cases of ESOS have been documented globally since their initial description in 1941.

Observation:

• A 66-year-old female presented with acute retroperitoneal bleeding requiring surgical intervention.
• Postoperative complications included bowel obstruction due to intestinal infiltration by a large omental tumor.

Findings:

• Histopathological analysis confirmed the omental tumor as extraskeletal osteosarcoma (ESOS).
• This specific case represents one of only a few reported instances of omental ESOS in the medical literature.

Implications:

• The diagnosis of unresectable omental ESOS necessitated a palliative colostomy.
• This case underscores the importance of considering rare soft-tissue sarcomas in the differential diagnosis of abdominal masses and bleeding, particularly in the omentum.