Langerhans cell histiocytosis of lymph nodes: a morphological assessment of 43 biopsies.

The morphology of Langerhans cell histiocytosis (LCH) involving lymph nodes was analyzed in 43 biopsies from 39 patients and findings were correlated with clinical data. Five histological motifs were recognized: sinusoidal, limited sinusoidal, epithelioid granulomatous, partial effacement, and total effacement. Lesions were composed of histiocytes of the Langerhans cell (LC) family, macrophages, multinucleated giant histiocytes, T lymphocytes, and eosinophils in varying proportions. Proliferative fractions ranged from 2.6 to 48% and 2 of 25 specimens showed a hyperdiploid aneuploid DNA ploidy profile. Epithelioid granulomas composed of histiocytes with the LC phenotype dominated three abdominal specimens, reflecting a picture of LCH not previously reported. Total effacement seen in three patients, was associated with unmarked histiocytoid cells, high proliferative fraction, aneuploid DNA ploidy profile, and, in two, a fatal outcome. Different histologic appearances in lesions from separate sites of the same patient were seen in the cases with epithelioid granulomas and in those with total effacement. The diverse histopathology in lymph nodes involved by LCH is considered in the context of current knowledge of this enigmatic disease.