Eosinophilic granuloma of lymph node. A case report.

Eosinophilic granuloma confined to the lymph node of a 25-year-old Japanese woman is reported. She presented with a low-grade fever and pain in the left cervical region. A finger-tip-sized cervical lymph node was excised for histological study. Microscopically, the normal architecture of the lymph node was distorted, and histiocytoid cells had proliferated mainly in the sinus. Numerous eosinophils and an appreciable number of large multinucleated cells were also observed. Ultrastructurally, Birbeck granules were found in the cytoplasm of the histiocytoid cells. Immunohistochemically, the proliferating cells and multinucleated cells were found to be positive for S-100 protein but negative for lysozyme in the cytoplasm. The patient has been well without recurrence for 10 months after the lymph node biopsy.