Oral tuberculosis presenting as a destructive lower-lip ulcer: A case report.

Oral and maxillofacial tuberculosis is uncommon, and labial involvement is unusual. This report describes lower-lip tuberculosis presenting as a destructive ulcer that clinically resembled malignancy and highlights the value of combined histopathological and microbiological assessment. A 24-year-old man presented with a three-month history of a progressively enlarging lower-lip ulcer causing functional interference and intermittent bleeding. Examination showed a solitary 18 × 11 mm ulcer with an irregular destructive surface, elevated margins, yellow-brown crusting and slough, haemorrhagic areas, and central necrosis. Incisional biopsy demonstrated mild epithelial dysplasia overlying necrotising granulomatous inflammation with Langhans-type multinucleated giant cells and caseous necrosis. No invasive carcinoma was identified in the examined tissue. A subsequent pretreatment biopsy submitted for mycobacterial culture yielded Mycobacterium tuberculosis complex (MTBC). Chest radiography showed no radiographic evidence of pulmonary tuberculosis, human immunodeficiency virus testing was negative, and no other tuberculous focus was identified on the available assessment. After two months of first-line treatment, the ulcer had decreased to approximately 5 × 3 mm. The case demonstrates that lower-lip tuberculosis can closely mimic malignancy. Necrotising granulomatous inflammation strongly supported tuberculosis but was not pathogen-specific, whereas microbiological confirmation established the aetiology. Concurrent mild epithelial dysplasia created an additional interpretative challenge because inflammatory and regenerative epithelial changes may overlap morphologically with dysplasia. Tuberculosis should remain in the differential diagnosis of persistent destructive lip ulcers. Representative tissue sampling, targeted microbiological investigation, and systemic assessment are essential for accurate diagnosis, appropriate classification, and avoidance of diagnostic closure.