Abstract
INTRODUCTION: Lupus vulgaris is the most common form of cutaneous tuberculosis. It may easily be overlooked if a proper differential diagnosis is omitted. CASE PRESENTATION: A 46-year-old Turkish woman presented with a 42-year history of erythamatous plaque on her left arm. Ziehl-Neelsen and periodic acid-Schiff stains did not show any acid-fast bacilli. Culture from a biopsy specimen was negative for Mycobacterium tuberculosis. The result of a polymerase chain reaction-based assay for Mycobacterium was negative. Histopathologic findings revealed a tuberculoid granuloma containing epithelioid cells, lymphocytes and Langerhans-type giant cells. A diagnosis of lupus vulgaris was made by clinical and histopathologic findings. CONCLUSIONS: The lesion improved after antituberculous therapy, confirming the diagnosis of lupus vulgaris.