The importance of eosinophilic cytoplasmic inclusion bodies in melanocytes as a clue to distinguish between benign and malignant melanocytic lesions

Abstract

Aim: Since early diagnosis and treatment of melanoma can significantly improve patients' prognosis, discovering new criteria to help differentiate between benign and malignant melanocytic lesions is of significance. In this study we aim to clarify the relationship between the presence of intracytoplasmic eosinophilic inclusion bodies inside melanocytes and the nature of the melanocytic lesion. Methods: Medical records and pathology slides pertaining to 187 patients with melanocytic lesions who had undergone biopsy in Razi Hospital between March 2014 and March 2015 were gathered. Slides were re-examined by a dermatopathologist using a light microscope. Clinical and pathological data were analyzed using SPSS. Results: A total of 196 specimens from 187 patients were studied. The median age of our patients was 42.26 years and 61.5% of them were female while 38.5% were male. The specific eosinophilic intracytoplasmic inclusion bodies were observed in 14 specimens; 8 of which were intradermal nevi and the remaining 6 were from compound nevi. These bodies tended to be present in lesions with congenital features. We found no correlation between age, sex or location of the lesion with the presence of aforementioned bodies. Conclusion: Eosinophilic inclusion bodies present in the cytoplasm of melanocytes are associated with benign melanocytic lesions and are mostly observed in cells with abundant vacuolated cytoplasm and in lesions with congenital features. Therefore these bodies can be helpful in diagnosing benign and longstanding lesions and differentiating them from malignancies.