Oral Diagnosis of Lepromatous Leprosy in a Hyperendemic Region of Brazil

BACKGROUND: Leprosy is a chronic infectious disease caused by Mycobacterium leprae that primarily affects the skin and peripheral nerves. Oral manifestations are rare and typically occur in advanced cases of multibacillary lepromatous leprosy. CASE PRESENTATION: An 18-year-old male from Tocantins, a hyperendemic region of Brazil, presented with widespread mucocutaneous papulonodular lesions affecting the face and extremities, as well as nodular and ulcerative lesions of the hard and soft palates and the uvula. Histopathological analysis revealed a diffuse subepithelial inflammatory infiltrate predominantly consisting of foamy macrophages exhibiting Virchow-like characteristics. Immunohistochemistry showed diffuse CD68 positivity. Fite-Faraco and Ziehl-Neelsen staining revealed numerous intracytoplasmic acid-fast bacilli. These findings, together with clinical features, established the diagnosis of lepromatous leprosy. CONCLUSION: Although oral manifestations of leprosy are uncommon, they may represent important diagnostic indicators of advanced multibacillary disease. Oral biopsy, combined with histopathological examination and special stains, remains essential for definitive diagnosis, particularly in hyperendemic regions where other granulomatous infectious diseases may coexist.