Paraganglioma-like dermal melanocytic tumor.

Paraganglioma-like dermal melanocytic tumor (PDMT) is a rare subtype of benign dermal melanocytic tumor, first described in 2004. Its histopathologic features resemble those of paraganglioma, showing presence of a distinctive partitioning of the tumor into small and large packets, nests, or short cords by delicate fibrous septa (zellballen pattern). But the immunostaining characteristics are those of melanocytic lesions, as PDMT express S-100, melan A, HMB 45 and lack pancytokeratin markers.