A flow cytometric study of Langerhans cell histiocytosis

Abstract

Langerhans cell histiocytosis (LCH), or histiocytosis X, is now generally considered to be a non-malignant condition. A flow cytometric (FCM) study of a single case has, however, been published which claimed to provide evidence to contradict this. The presence of DNA-ploidy as detected using this technique is a feature of malignant and pre-malignant disease. In this reported single case, DNA-ploidy was present but the clinical features of this patient were atypical for LCH. We have performed a FCM study of the DNA of nine biopsies of LCH lesions from six patients with well-established disease. In addition, in one of these, fresh tissue studies including the use of an anti-CDI monoclonal antibody to specifically label the LCH clels were performed. In all cases the DNA content of the cells was entirely normal. We therefore found no evidence that LCH is a neoplastic disorder.