Tissue Diagnosis of Two Distinct Eosinophil Rich Lesions With Similar Histomorphology

Abstract

Eosinophil rich lesions in histopathology have a wide range of differential diagnosis including conditions arising from inammatory, reactive, immune mediated, drugs, parasitic infestations to neoplasms of both hematopoietic and non-hematopoietic origin (Nutman, 2007). Some of them are yet to be clearly differentiated by histological criteria, though being genetically different, such as Kimura disease and Angiolymphoid hyperplasia with eosinophilia (ALHE) (Googe et al., 1987). Some close mimics of eosinophil rich reactive and clonal lesions need to be differentiated based on the site of involvement, radiological features and appropriate immunohistochemical evaluation on biopsy tissues. We present here two distinct diagnoses of Langerhans cell histiocytosis (LCH) and ALHE which appear similar in terms of eosinophil rich inammatory inltrate on histological examination but have entirely different clinical course. Summary: Langerhans cell histiocytosis is a locally aggressive slow growing neoplasm while Angiolymphoid hyperplasia with eosinophilia is a reactive lesion. Problem arises sometimes in the tissue diagnosis of these two lesions owing to their similarities in a couple of features. Both have a predilection for head and neck region. Both appear as an inammatory lesion with eosinophils being a striking feature in biopsy tissues. Since, both the lesions have an entirely different clinical behaviour and prognosis, it is important to differentiate between the two based on the histopathology, clinical as well as radiological features. This paper emphasizes upon the same.