Morphological, immunohistochernical and ultrastructural study of langerhans cell histiocytosis

ABSTRACT

A total of 23 samples of 21 patients designated Langerhans cell Histiocytosis [LCH] or eosinophilic granuloma were collected. Light microscopy showed that the picture of LCHs was a mixture of Langerhans [LCs] and eosinophils in varying proportions along with occasional giant cells of foreign body and Langhans giant cells, lymphocytes and neutrophils. Immunohistochemical study of the 21 cases [23 specimens] of LCHs showed mostly negative staining for alph alpha-1- antitrypsin. Out of the 23 specimens, 19 specimens [83%] were positive for S 100. CD Ta 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 non-specific as the histiocytes showed positive staining also. All the 21 cases [23 specimens] 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 an inconspicuous nucleoli. It was concluded that the diagnosis of LCH should be based on the presence of at least two out of four which are-1- The clinical findings including radiological investigations 2- the presence of the typical Langerhans cells and eosinophils by light microscopy 3- positivity for CD Ta [OKT-6] by immunohistochemistry 4- The presence of Birbeck granules by electron microscopy