Endometriosis of the sciatic nerve

This code describes the presence of endometrial tissue abnormally located on or infiltrating the sciatic nerve. This ectopic tissue responds to hormonal fluctuations, leading to inflammation, pain, and neurological dysfunction along the sciatic nerve distribution. Patients typically present with cyclical or chronic sciatica-like symptoms.

Use this code when documentation clearly indicates a diagnosis of endometriosis affecting the sciatic nerve. This diagnosis is often confirmed through imaging (e.g., MRI) or surgical findings, especially in patients with a history of endometriosis and unexplained neuropathic leg pain.

• Ensure documentation specifies the sciatic nerve as the affected site of endometriosis, not just general pelvic or abdominal endometriosis with radiating pain.
• Consider sequencing this code after a more general endometriosis code (e.g., N80.9) if the sciatic nerve involvement is a manifestation of widespread disease.
• Distinguish from other causes of sciatica; the diagnosis must explicitly link the nerve involvement to endometriosis.