Malignant neoplasm of peripheral nerves of pelvis

This code signifies a primary cancerous tumor originating in the peripheral nerves located within the pelvic region. These nerves include, but are not limited to, the sciatic nerve, femoral nerve, obturator nerve, and pudendal nerve, as they traverse the pelvis. The neoplasm is characterized by uncontrolled cell growth with the potential for invasion and metastasis.

Assign this code when documentation clearly indicates a primary malignant neoplasm affecting the peripheral nerves of the pelvis. This typically applies to diagnoses such as malignant peripheral nerve sheath tumor (MPNST) or neurofibrosarcoma arising in this anatomical area. Supporting documentation should include pathology reports confirming malignancy and imaging studies or operative reports specifying the pelvic peripheral nerve involvement.

• Differentiate from secondary (metastatic) neoplasms to the peripheral nerves; use a secondary malignancy code for those cases.
• Ensure the documentation specifies "peripheral nerves" and not other pelvic soft tissues, which would fall under different C49 codes.
• Sequence this code as the primary diagnosis when it is the reason for the encounter, followed by any associated symptoms or complications.