Poroma

Poromas are benign tumors of the distal sweat duct.

A poroma is a benign skin tumor derived from sweat glands. Although the original term poroma was initially used to describe a tumor derived from the ductal epithelium of eccrine sweat glands, the term is used in general reference to tumors derived from ductal portions of both eccrine and apocrine sweat glands. Specific sub-types are primarily defined by location of tumor, and include:

• eccrine poroma
• hidroacanthoma simplex (intraepithelial poroma)
• dermal duct tumor (intradermal poroma)
• syringoacanthoma
• syringofibroadenoma
• poroid hidradenoma (disputed as different family)

Eccrine poroma

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 which are continuous with the epidermis (H&E staining, original magnifications ×10 and ×40, respectively).

An eccrine poroma specifically refers to a tumor derived specifically from the most apical portion of eccrine sweat gland (acrosyringium). They are most commonly found on acral distribution (on palms and soles), and most commonly in adults. They are described as < 1–2 cm pink/red shiny, exophytic lesions that can be pigmented and are clinically very similar to pyogenic granulomas. Histologically, the cells as PAS-positive and clearly surrounded by normal keratinocytes. These tumors are surgically excised usually without complication or recurrence, although malignant porocarcinomas can recur and metastasize to local lymph nodes.

• 

  Poroma eccrinale (Hidroacanthoma simplex)

• 

  Eccrine clear cell poroma

See also

• Hidradenoma
• Basal cell carcinoma
• Seborrheic keratosis