Dermatopathic lymphadenopathy and lymph node involvement in mycosis fungoides

Lymph node involvement in mycosis fungoides (MF) is associated with a poor prognosis, Histologically, in most cases of clinical lymphadenopathy the excised lymph node shows dermatopathic lymphadenopathy (DL). The diagnosis of MF involvement can readily be made when the lymph node tissue has partly or wholly been replaced by atypical lymphoreticular tissue. Early involvement of a dermatopathic lymph node by MF may be difficult to diagnose. A histologic study was performed on 30 lymph nodes from 24 patients with MF. Most of these lymph nodes had been excised as part of the staging procedure. The maximal follow-up period was five years. A classification of lymph node involvement into four categories is suggested and correlations with clinical courses and results of DNA cytophotometry of lymph node imprints are shown. Lymph nodes showing the histologic picture of DL can be divided into two groups: a group with MF involvement (category I) and a group with MF involvement (category II). The latter group is considered to represent early involvement of lymph nodes by MF. Partial or complete replacement of lymph node tissue by atypical lymphoreticular tissue corresponds with cagegories III and IV, respectively.