Endometriosis of the mediastinal space

This code identifies the presence of endometrial tissue abnormally located within the mediastinum, the central compartment of the thoracic cavity. This is a rare form of extragenital endometriosis, where tissue similar to the lining of the uterus grows outside the uterus, causing inflammation and potentially symptoms like chest pain or dyspnea.

Apply this code when documentation clearly indicates a diagnosis of endometriosis specifically affecting the mediastinal space. This diagnosis is typically confirmed through imaging studies (e.g., CT, MRI) and/or biopsy demonstrating endometrial glands and stroma in the mediastinal tissue. Use this code for patients presenting with symptoms referable to the chest, where mediastinal endometriosis has been identified as the underlying cause.

• Ensure the documentation explicitly states "mediastinal space" or "mediastinum" in relation to endometriosis.
• Do not confuse this with other thoracic endometriosis sites, such as pleural or diaphragmatic endometriosis, which have different codes.
• Code any associated symptoms (e.g., chest pain, dyspnea) as secondary diagnoses.