Perforating granuloma annulare mimicking keratoacanthoma: A case report

Perforating granuloma annulare (PGA) is a infrequent type of granuloma annulare. PGA has a chronic course. The etiology and perforation mechanism are still obscure. We submit a case of a 32-year-old male patient who presented with a 2-month history of asymptomatic lesion on the dorsum of his hand. He did not report the use of any medication, infection, vaccine, trauma, autoimmune disorders, heart disease, and malignancy. Complete blood count, thyroid function tests, lipid profile parameters, and fasting blood glucose were within normal ranges. Moreover, the human immunodeficiency virus was negative. Histopathologic examination revealed that accumulation of mucin was at the center of the histiocytic reaction, which was grouped in places. Therefore, we diagnosed PGA with clinical and histopathological data. The presented case emphasizes that PGA should be considered in the differential diagnosis of keratotic/ umbilical papules on the dorsum of the hand.