MRI of head and neck paracoccidioidomycosis.

Paracoccidioidomycosis, caused by the dimorphic fungus Paracoccidioides brasiliensis, is the most important systemic mycosis in Latin America. Imported cases have been reported in North America, Asia and Europe, in individuals who lived in endemic areas, sometimes many years before the development of clinical manifestations. The disease causes cutaneous and/or respiratory tract mucosal lesions as well as lymph node enlargement. Involvement of the oropharynx and/or the larynx, either alone or in association with pulmonary involvement, is one of the commonest clinical presentations. On MRI, the major features are mucosal lesions, usually hypointense on T1 weighted images and hyperintense on T2 weighted or fat suppressed images, affecting the oral cavity, oropharynx and larynx, with head and neck lymph node enlargement. Differential diagnosis includes other granulomatous infectious diseases, especially tuberculosis, and cancers such as squamous cell carcinoma and lymphomas.