Pigmented eccrine poroma in an atypical location

A Pigmented Pedunculated Nodule on the Scalp

“…Poromas feature a stroma that is both highly vascularized and myxoid. [ 1 2 3 4 5 6 7 8 ] Notably, pigmented EP with melanin granules has also been reported in patients of Caucasian descent implicating that racial disparities do not appear to be exclusively associated with pigmentation in EPs. [ 1 2 3 4 5 6 ] Ohata U, et al , hypothesized that melanocytes from the surrounding epidermis may migrate to the tumor nests under the influence of tumor-derived growth factors such as basic fibroblast growth factor (bFGF), potentially triggering colonization by melanocytes and their subsequent multiplication.…”

“…As far as our current understanding goes, the occurrence of pigmentation in EPs is uncommon, accounting for 17% of cases. [ 8 ] Subsequent investigations dedicated to comprehending melanocyte symbiosis within the tumor are imperative to elucidate the underlying mechanism governing melanocyte colonization in poromas.…”

Eccrine Poroma with Concurrent Basal Cell Carcinoma: A Rare Combination

“…They are mainly composed of cuboidal cells of the same size and shape, closely arranged, and deep basophilic nuclear and intercellular bridges can be seen; (2) The boundary between tumor cells and surrounding tissue is clear, but the surrounding cells of tumor body are not arranged in a palisade; (3) A narrow lumen or cystoid structure can be seen in the tumor strip, lined with a PAS-positive or EMA and CEA positive sheath and a layer of lumen cells; [10][11][12] (4) Characteristic tumor cells contain a large amount of glycogen, resulting in cytoplasmic clarity, but usually 6) In general, melanocytes and melanin particles are not seen in the tumor, but occasionally, poroma can be pigmented. 13 BCC is the most common cutaneous malignancy. It often occurs on the face, hands and feet and other sun-exposed parts.…”

Pigmented Eccrine Poroma on the Palm Mimicking Nodular Melanoma

“…Eccrine poromas represent 10% of sweat gland tumors, arising in the intraepidermal section of eccrine sweat ducts [ 2 ]. Rarely pigmented, the brownish coloration arises from scattered dendritic melanocytes within tumor cells [ 1 ]. There is no consensus on the dermoscopic features of PEP.…”