Poroma

[1][3] Poromas usually occur as single, small, skin tumors that develop in middle aged to elderly individuals.

[2] They usually occur in the elderly population (mean age 65.1–66.6 in different studies) as small (<2 centimeters), solitary dome-shaped papules, plaques, or nodules, that are skin-colored, pink, red, white, or blue and range from smooth to wart-like, ulcerative,[4] or pyogenic granuloma-like lesions.

[10] They may be located on the palms of the hands, soles of the feet, trunk, face, neck, or other cutaneous surfaces[4] such as the areola,[11] nipple,[12] or other areas of the breast,[13] on the scrotum,[14] or on the vulva.

[3] Poromas present more commonly in: pregnancy;[3] patients treated with electron therapy for mycosis fungoides; sites of chronic radiation dermatitis caused by long-term radiation exposure;[4] patients who received chemotherapy with or with radiation therapy (these patients have often presented with poromatosis);[16] individuals with underlying skin conditions such as hypohidrotic ectodermal dysplasia and Bowen’s disease (i.e. a form of squamous cell carcinoma that is localized to the outermost layer of the skin); and skin plaques of individuals with the congenital disease, nevus sebaceous.

[3] Poromas are usually slow growing and asymptomatic but some individuals report that their lesions are itchy,[4] mildly tender, or painful.

[9] An existing poroma that develops spontaneous bleeding, ulceration, sudden itching, pain, or rapid growth over a short period of time may indicate that it has become a cancerous porocarcinoma.

[4] These cancers may metastasize to local lymph nodes, nearby or distal skin sites, bones, bladder, breast, retroperitoneum, ovary, liver, lung,[17] brain, or stomach.

They have been misdiagnosed as other types of skin tumors including porocarcinomas, basal cell carcinomas, pyogenic granulomas, skin tags, plantar warts (i.e. warts on the palms or soles), fibromas, hemangiomas, pigmented moles, seborrheic keratosis, trichilemmomas, melanomas, Kaposi sarcomas, and other adnexal tumors.

[7] Dermatoscopy, particularly when revealing a "leaf- and flower-like pattern" in a skin tumor, has been used as a strong indicator that the lesion is a poroma, but confirmation of this diagnosis ultimately relies on histopathological analyses.

Poromas are benign tumors of the distal portion of sweat gland ducts.
Dermoscopy and histopathology of eccrine poroma: (A) Clinical presentation of a nonpigmented eccrine poroma sensu stricto as a pink nodule located on the foot (B,C) Dermoscopy shows milky red areas (light blue arrow), milky red globules (dark blue triangle), and dotted vessels (black arrow) (original magnifications ×20 and ×40, respectively). (D,E) Histopathologically, the neoplasm consists of poroid and cuticular cells and tubular structures that are continuous with the epidermis (H&E stain, original magnifications ×10 and ×40, respectively). [ 19 ]