[Lymphomatoid granulomatosis vs. leprosy].

Lymphomatoid granulomatosis (LYG) was first described by LIEBOW, A.A. et al. Histologically is characterized by an lymphohistiocytic infiltrate with granulomatous features, polymorphous and pleiomorphic, angiocentric and angiodestructive and mainly involves lungs, skin, kidneys and CNS. LYG does not involves spleen, bone marrow and lymph nodes. Presently there is a concept that LYG is an angiocentric variant of T-cell peripheral lymphoma and histologically indistinguishable from polymorphic reticulosis of the upper airways (midline lethal granuloma). The prognosis for patients with LYG is guarded. Treatment with cyclophosphamide and prednisone may lead to remission in early cases. The skin is the most commonly involved extrapulmonary organ and in 13 to 34% of patients the skin lesions precede the pulmonary involvement. The clinical features of the skin lesions may vary, but frequently they are erythematous and violaceous plaque lesions or annular infiltrated lesions with central clearing. The differential diagnosis of these lesions includes granuloma annular, sarcoidosis and Hansen's disease. Since Hansen's disease is common among us and that LYG includes involvement of cutaneous branches and nerve trunks, with hypo or hyperesthesia in skin lesions and paresthesia of limbs, it is of utmost importance to make differential diagnosis. This report deals with a 42 years old male with cutaneous lesions of LYG and concomitant pulmonary and systemic manifestations. A first skin biopsy roughly suggested tuberculoid leprosy due to a granulomatous and perineural localization of cellular infiltrate. The patient died on respiratory insufficiency and the necropsy findings of the skin revealed important histological modifications. The infiltrate was more polymorphous, pleiomorphic and angiocentric. The same histological features were found in CNS, heart, digestive tract, liver, prostate, testes, lungs and kidneys. In these two last organs there were large nodules made of the characteristic cellular infiltrate and also large necrotic areas.