Abstract
An 82-year-old woman was referred to us because of a slightly pruritic eruption on the right cheek. It had gradually enlarged in size over several years. Physical examination revealed a slightly pruritic, scaly erythematous plaque, 6×4cm in size, on the right cheek. A histopathologic specimen showed granuloma with central infiltration of epithelioid cells and Langhans giant cells and peripheral infiltration of lymphocytes without caseous necrosis in the upper and lower dermis. QuantiFERON TB Gold showed a positive reaction. We suspected that the eruption was lupus vulgaris, but acid-fast bacilli were not detected by Ziehl-Neelsen staining in a biopsied specimen and Mycobacterium tuberculosis DNA was not identified by polymerase chain reaction. However, Mycobacterium tuberculosis grew in a culture from a biopsied specimen on Ogawa egg medium three weeks later. Thus, we diagnosed the eruption as lupus vulgaris. Our case reemphasizes the importance of the detection of Mycobacterium tuberculosis by various methods of examination when we clinically and histopathologically suspect an eruption to be lupus vulgaris.Skin Research, 13: 172-175, 2014
