Eosinophilic granuloma of lymph nodes--a variant of histiocytosis X.

A clinicopathologic study of histiocytosis X in lymph nodes disclosed a special variant: primary eosinophilic granuloma of lymph nodes. This variant involves one or more lymph nodes, but does not infiltrate any other organs. Histologically, the infiltration of lymph nodes by histiocytosis X cells and eosinophils is similar to that seen in disseminated or metastatic histiocytosis X. Most cases of eosinophilic granuloma of lymph nodes are recognizable as primary, however, by the heavy infiltration of the surrounding tissue. The predominant proliferating cells are histiocytosis X cells ('Langerhans cells'), which contain Birbeck granules on electron microscopy and are lysozyme-negative. The disease was found in 30 patients among a total of 64 cases of histiocytosis X collected at the Lymph Node Registry in Kiel. Primary eosinophilic granuloma of lymph nodes occurs predominantly in children and young adults and shows a slight preponderance of males. Clinically, the patients present with mostly afebrile and sometimes painful lymphadenopathy, which is more often solitary (in the cervical or inguinal region) than widespread. The erythrocyte sedimentation rate and/or serum alpha 2-globulin level are elevated in many patients. There may also be an increase in the number of leucocytes, especially eosinophils, in the blood. The prognosis is favourable: the lymphadenopathy disappeared spontaneously in most patients and only one patient developed two recurrences. Thus, primary eosophilic granuloma of lymph nodes is interpreted as a benign lesion. It might be a special reaction of the T cell system.