Langerhans cell histiocytosis: morphological, immunohistochemical and ultrastructural study

ABSTRACT

A total of 23 samples of 21 patients designated Langerhan's cell histiocytosis [LCH] or eosinophilic granuloma was collected for this study. Light microscopy showed that the picture of LCHs was a mixture of Langerhan's [LCs] and eosinophils in varying proportions along with the occasional giant cells of foreign body and Langerhan's giant cells, lymphocytes and neutrophils. The immunohistochemical study showed mostly negative staining for alpha-1-antitrypsin. Out of the 23 specimens, 19 were positive for S100. CD Ia was performed on all cases with 100% positivity. The macrophages were negative for CD Ia and S100, but were positive for alpha-1-antitrypsin. The staining for NSE was positive for 19 specimens, but it was nonspecific as the histiocytes showed also a positive staining. All the 21 cases studied by electron microscopy had the characteristic features of Langerhans' cell histiocytosis in the form of Birbeck granules along with the deeply cleaved or pseudo-multisegmented nuclei with finely dispersed, thinly marginated chromatin and inconspicuous nucleoli