Concurrent presentation of porocarcinoma and basal cell carcinoma arising on a capillary malformation: a case report.

Porocarcinoma (PC) and basal cell carcinoma (BCC) are distinct skin cancers. Few studies have documented the occurrence of two concurrent types of skin cancers, and to the best of our knowledge, this represents the inaugural report of such a coexisting lesion arising from a capillary malformation. Herein, we report a case of concurrent PC and BCC presenting with capillary malformation. A 93-year-old woman visited our hospital with a protruding mass in her right nasal ala that appeared as a capillary malformation. A biopsy was performed on the skin lesion, and BCC was diagnosed. A wide excision was performed. Permanent biopsy revealed that the skin lesion was a PC with basal cells and squamous differentiation. The safety margin of the deep tissue margin was < 0.1 cm; however, considering the advanced age of the patient, further excision was deemed to not possess any benefits. This case illustrates the importance of recognizing the possibility of multiple skin cancers, even in patients with benign lesions such as capillary malformations. The rarity of this presentation highlights the importance of thorough investigation and histopathological examination of skin lesions in guiding appropriate surgical excision.