The term of primary paraganglioma-like dermal melanocytic tumor (PDMT) was coined by Deyrup, et al [1
] in 2004. PDMT is considered as a unique benign neoplasm derived from melanocytes. The lesion may be confused with other benign dermal tumors, such as cellular blue nevus and granular cell tumor or malignant dermal tumors, such as melanoma [2
]. The total number of cases described in the English literature is about 8 [1
]. It is often seen in patients aged 18–53 with a female preponderance. It is not associated with Carney's syndrome or prior melanoma. Clinically, it presents as a non-pigmented skin nodule averaging 1.4 cm in diameter. Microscopically, the tumor is typically a well demarcated dermal neoplasm with normal overlying epidermis. Junctional melanocytic proliferation or nevoid nest is usually not present. It is comprised of large epitheliod cells in an organoid or nest-like pattern separated by delicate fibrous strands and blood vessels. There is no necrosis but increased mitotic activity can be rarely encountered. These histopathologic features are reminiscent of those of paraganglioma. However, primary cutaneous paraganglioma remains a very rare tumor. Only one such case has been reported in 2006 in the scalp of a 10-year-old boy [3
]. The fact that the skin contains nerves and melanocytes but is devoid of ganglia may explain the rarity of cutaneous paraganglioma. The tumor cells of paraganglioma are usually negative for melanocytic markers, such as Melan-A, HMB-45, and MITF. PDMT is considered a variant of benign dermal melanocytic nevus with benign clinical behavior [1
]. Other malignant and potentially malignant dermal tumors, such as melanoma and dermal melanocytic tumor of uncertain potential [4
] can be excluded because of the absence of any atypical features, such as nuclear atypia, macronucleoli, increased mitotic activity, and necrosis.
The purpose of this report is to familiarize clinicians and pathologists with such a rare type of benign dermal melanocytic tumor.