Malignant neoplasm of connective and soft tissue of pelvis

This code signifies a primary cancerous tumor originating in the connective or soft tissues (e.g., muscle, fat, fibrous tissue, blood vessels, nerves) located within the pelvic region. This includes various sarcomas such as liposarcoma, leiomyosarcoma, or rhabdomyosarcoma affecting structures like the pelvic floor, retroperitoneum within the pelvis, or pelvic wall.

Assign this code when documentation confirms a malignant neoplasm of soft or connective tissue with its primary site identified as the pelvis. This applies to diagnoses such as pelvic soft tissue sarcoma, malignant fibrous histiocytoma of the pelvis, or liposarcoma of the pelvic retroperitoneum. Supporting documentation should clearly specify the histology as malignant and the anatomical location as the pelvis.

• Differentiate from malignant neoplasms of bone (C40-C41) or specific pelvic organs (e.g., C53 for cervix, C56 for ovary).
• Ensure the documentation specifies "connective and soft tissue" to avoid confusion with other pelvic malignancies.
• If the neoplasm is metastatic to the pelvis, a secondary malignancy code (C79.-) should be used instead, with the primary site coded separately.