Congenital and acquired lesions of the nasal septum: a practical guide for differential diagnosis.

Many different types of lesions may involve the nasal septum, and some can destroy it. Congenital nasal septal anomalies are rare and tend to have fairly typical imaging features, which, when considered alongside the imaging appearance of the normal anatomy, help determine the correct diagnosis in most instances. By contrast, many acquired lesions have nonspecific imaging features, and their diagnosis therefore must be based also on the patient's age and the histologic findings. Acquired nasal septal abnormalities may be caused by trauma, infection, toxicity, inflammation, or tumors. Traumatic lesions may result from surgery or from repetitive behaviors such as rhinotillexomania. Frequent use of decongestants and cocaine also may erode the nasal septum. Bacteria, mycobacteria, and fungi may cause infections of the nasal septum, particularly in immunocompromised patients. Inflammatory diseases that may affect the nasal septum include sarcoidosis, reparative granuloma, and Wegener granulomatosis. Last, the tumors that may arise in the nasal septum or may involve it secondarily include carcinomas, Pindborg tumor, sarcoma, angiofibroma, hemangioma, neuroendocrine tumor, and schwannoma.