CASE
An 82-year-old African American male (Fitzpatrick Type V) presented with a tender, bleeding exophytic growth on the right lateral foot enlarging over the preceding three months. Examination showed a 0.9 x 0.7 cm exophytic erythematous papule with collarette and yellow, hemorrhagic crust (Figure 1A). Dermoscopy showed multiple colors with pale pink, red, yellow, and brown islands (Figure 1B). Vascular structures were not detected on dermoscopy.
Two years prior, podiatry described the lesion as a 1 cm well-circumscribed, elevated, torn cyst-like lesion with mild bleeding and no signs of infection. An x-ray revealed "ovoid density measuring 7 mm along the lateral plantar aspect of the foot which may correspond to a foreign body." However, the patient had no recollection of trauma. Podiatrists performed four superficial debridements, curettage and silver nitrate treatments for multiple diagnoses including hemangioma and "skin tag-like lesion" resulting in temporary improvements, but the lesion kept recurring. Dermatologic history included a plantar wart on the right foot nine years prior, treated by podiatry with salicylic acid and urea cream, congenital dermal melanocytosis, seborrheic keratoses, and tinea pedis. Medical history was otherwise not relevant.
The differential diagnosis included both inflamed benign lesions (poroma, pyogenic granuloma, and verruca) and malignancies (amelanotic melanoma, squamous cell carcinoma, and porocarcinoma). A shave biopsy was performed and the base was electrodessicated with a hyfrecator. Dermatopathology showed proliferation of uniform basophilic staining cuboidal epithelial cells, emanating from the epidermis, forming anastomosing bands extending throughout the dermis, confirming the diagnosis of eccrine poroma (Figure 2). The site healed well without sequelae or recurrence at one-year follow-up.
