Histopathology of the lepromatous skin biopsy

Borderline Tuberculoid Leprosy Masquerading as Granuloma Annulare: A Clinical and Histological Pitfall

“…The presence of "numerous large" Langhans giant cells has been regarded as pathognomonic for TT, but these were prominent in our case of BT. 6,7 However, our patient presented with multiple plaques and AFB demonstrable within Schwann cells, consistent with BT leprosy. The predilection of M. leprae to infect Schwann cells was recently revealed as an elaborate mechanism to reprogram Schwann cells into progenitor stem-cell-like cells promoting bacterial spread and survival at the expense of host neural function.…”

“…3,4 At one end of the spectrum, tuberculoid leprosy (TT) is characterized by one to few well-defined anesthetic hypopigmented or erythematous macules associated with peripheral nerve enlargement. 1,7 Because of the predominant cell-mediated immune response, there is usually an absence of acid-fast bacilli on histochemical staining. 1,7 Because of the predominant cell-mediated immune response, there is usually an absence of acid-fast bacilli on histochemical staining.…”

“…3 In between the 2 polar subtypes, borderline tuberculoid leprosy (BT) presents similar to TT, with few to many annular erythematous plaques with central hypopigmentation and associated anesthesia. 7 Histochemical staining typically reveals few organisms within Schwann cells of peripheral nerve fibers in the dermis. The presence of "numerous large" Langhans giant cells has been regarded as pathognomonic for TT, but these were prominent in our case of BT.…”

Panniculitis by leprosy: Case report of a diagnostic challenge

“…At this juncture, the name erythema nodosum is inadequate, since leprosy does not present the septal pattern characteristic of that disorder [8,10].…”

O uso da expressão de CD64 nos neutrófilos como marcador de severidade do eritema nodoso hansênico

“…Histologicamente, nas lesões agudas, ocorre intenso infiltrado perivascular neutrofílico na derme e subcutâneo, algumas vezes formando micro abscessos, com ou sem alterações típicas de vasculite, como necrose fibrinóide da parede dos vasos, edema e formação de trombos intravasculares (MASSONE et al,2015). A medida que a lesão vai se tornando crônica, diminui o número de neutrófilos e aumenta o de linfócitos, plasmócitos e histiócitos.…”