Idiopathic Scrotal Calcinosis: Analysis of Epithelial Origin By Immunohistochemical Methods

Özet

Objective: Scrotal calcinosis (SC) is a rare, usually asymptomatic, benign condition charac- terized by calcium phosphate deposition in the skin of the scrotum. The aim of this study is to investigate the clinical findings of patients diagnosed with scrotal calcinosis and to analyze the presence of possible epithelial origin by immunohistochemistry. Methods: Fifteen patients diagnosed with scrotal calcinosis by excisional biopsy in two different centers between 2011 and 2020 were included in the study. Demographic, clini- cal, and laboratory data of the patients were obtained retrospectively from the electronic archive. Hematoxylin & Eosin (H&E) sections prepared from all cases were re-evaluated by two pathologists. Cytokeratin AE1-AE3 immunohistochemical stain was applied to 13 cases for the epithelium of the cyst. Results: The median age of the patients was 32 (4–68). Patients had ulcer-free, white-yel- low, painless nodules measuring 0.5 to 2 cm, mostly in the ventral part of the scrotum, and three had pruritus. Serum calcium levels were normal in eight patients. Histopatholog- ical examination showed amorphous and dense, H&E and basophilic calcium deposits with pseudocapsules in the scrotal dermis, most of which had no cyst walls or epithelization. While macrophage infiltration or hyalinization was observed around these areas, ossification was present in one case. While epidermal cysts were observed in the periphery in five cases, calcification, keratinization, and epithelial passage were observed together in two of them. In these areas, the cyst epithelium was positive with cytokeratin AE1-AE3 immunohisto- chemically. Cysts with cyst epithelium and calcification were smaller than those with only calcification. Conclusion: Although the pathogenesis of idiopathic scrotal calcinosis is not clear, the cys- tic change and calcification in the cyst epithelium and the replacement of the epithelium by calcium appear to be the most likely mechanism after dilatation of the hair follicle.