Lymph node histopathologic aspects in cutaneous lymphomas of the mycosis fungoides or Sézary syndrome type. Retrospective study of 98 biopsies

: The results of a retrospective study of 98 lymph nodes in 89 patients with documented mycosis fungoides (M.F.) are reported. According to the histopathological aspect, three groups are determined: group I of 20 lymph nodes with lesions of dermopathic lymphadenopathy; group II of 27 lymph nodes, presenting variable-sized clusters of atypical cerebriform lymphocytes located in paracortex without homogenization; group III of 51 lymph nodes with partial or total homogenization; according to the different cytologic types, four histopathologic forms are described in group III: small, large, mixed and immunoblastic cellularly type. The paracortical changes of dermopathic lymphadenopathy observed in group I cannot be distinguished from those in patients with unrelated diseases. All histopathological aspects of group III correspond to a specific MF involvement. The most difficulties are caused by lymph nodes from group II; in order to detect an early MF involvement, the histopathologist has to find a partial infiltration of paracortex by atypical large and numerous lymphocytes. Morphometric and immunohistochemical methods previously reported are useful but they are expensive and they cannot be usually carried out. Because of the heterogeneity of the lesions a perfect routine paraffin-embedded with serial sections seems to be the most helpful way for recognition of early MF involvement in lymph nodes. In our series, as in literature, correlations with clinical course show that lymph node involvement classified in group III is pejorative. But it seems that histo-prognostic evaluation based on a suspicion of early involvement has to be carefully established because of the lack of significant difference of clinical behaviour between group I and group II.