Idiopathic Penile Calcinosis Cutis: A Histopathological Case Report

<b>Background</b> <b>and Clinical Significance</b>: Calcinosis cutis is a rare condition that can develop through several mechanisms. These include dystrophic, calciphylaxis (classical, metastatic, and iatrogenic), and idiopathic mechanisms. Idiopathic calcinosis cutis is rare and always a diagnosis of exclusion. A particularly rare site for the development of idiopathic calcinosis cutis is the penis. <b>Case Presentation</b>: A previously healthy 18-year-old male presented to our institution with a three-month history of a painless, firm swelling on the outer layer of the prepucium in the area of the commissure. Histopathology of the excised specimen showed a varying caliber of calcium deposits within the dermis, ranging from small psammoma-like bodies to larger calcium deposits measuring up to 2.5 mm. The deposits were freely dispersed within the dermal collagen and did not exhibit vascular affinity, nor surrounding foci of inflammation. The epidermis was not involved, with only mild reactive hyperkeratosis. The results of detailed physical, imaging, and laboratory tests were normal, and hence the diagnosis of idiopathic calcinosis cutis of the penis was established. <b>Conclusions</b>: Penile calcinosis cutis is a rare condition that falls within the broader group of genital calcinosis cutis. The condition is typically present in young males and has an excellent prognosis after excision.