CT findings in involvement of the paranasal sinuses by lepromatous leprosy.

The role of nasal infection in the transmission of leprosy has been extensively studied. Leprosy can affect the paranasal sinuses due to mucosal continuity and bacillaemia. This prospective study was performed on 25 untreated patients with lepromatous leprosy. 5 mm contiguous axial and coronal CT sections of paranasal sinuses, on soft tissue and bone windows, were obtained in all patients. Each sinus was examined for mucosal thickening, soft tissue densities and bony outlines. Representative biopsies were taken from ethmoid sinus to confirm the radiological diagnosis in 12 patients with multiple paranasal sinus involvement. Ethmoid aircells were involved in 20 patients (80%). Maxillary, frontal and sphenoid sinuses showed abnormalities in 12, four and three patients, respectively. The ethmoid biopsy showed involvement by lepromatous leprosy in seven of 12 patients (58.3%). Involvement of paranasal sinuses is common in lepromatous leprosy and is of considerable epidemiological significance.