Análise quantitativa e comparativa das células de Langerhans na micose fungoide e na pele normal

Abstract

Mycosis fungoides (MF), non-Hodgkin lymphoma, T cell epidermotropic, in most cases, CD4 positive, represents the most common subtype of primary cutaneous lymphomas (PCL). Clinically, the lesions appear as patches that develop into plaques and tumors. Has an indolent course and most patients consists of adults, occurring more in men than in women. The pathogenesis of MF is controversial. Factors potentially involved in its pathogenesis include persistent antigenic stimulation, exposure to chemicals, infections, medications and exposure to sunlight. The role of Langerhans cells (LC) in the pathogenesis of the LCP, especially MF, has been under discussion since the 80's. Some authors do not observe, using the electron microscopy, proximity between the LC and neoplastic lymphocytes of MF and concluded that LC plays no role in the pathogenesis of MF. However, there are authors who believe that LC is associated with survival of patients by influencing the defense mechanism of the individual, controlling instead of favoring the proliferation of malignant T lymphocytes. There are studies reporting the influence of epidermal LC in cutaneous T-cell lymphoma (CTCL), where memory T cells CD4 + are grouped in the epidermis close to the LC, constituting the microabscesses of Pautrier, saying that CTCL are dependent of LC for their proliferation and growth. Our hypothesis is that there is a relationship between the proportion of intraepidermal Langerhans cells and development of mycosis fungoides, which would be increased in the early stages and decreased with disease progression. Our objective in this study was to analyze and compare quantitatively the Langerhans cells in the epidermis at the stage of the patch, plaque and tumor of mycosis fungoides and in normal skin, in order to assess its relationship with disease progression. We did a retrospective study of patients with MF, before treatment, diagnosis in basis of clinical and pathological criteria, between 2006 and 2010. We selected 16 cases of MF stage patch, 15 plaque lesions and 10 tumors, which were compared with 12 fragments of normal skin. The cases were reviewed by three pathologists. Immunostaining was performed for identification of LC using anti-CD1a antibody, counterstained with Giemsa. The CD1a positive LC were quantified in the epidermis, using the system of Aperio's digital pathology. Patients with lesions in the patch stage were on average 19.7 younger than those with plaque lesions and 21 years younger than those with tumors. Among the histopathological criteria analyzed, epidermotropism was the most frequent, followed by disproportional exocytosis. The Pautrier microabscesses were seen in 39% of cases. We demonstrated statistically significant increase in the amount of LC between the patch stage of MF and normal skin. There was no statistically significant difference between the phases of the MF. We conclude that LC are possibly related to induction of MF, there are no sufficient criteria to assess their relationship with disease progression