Eccrine Poroma

Figure 5.4
A: Eccrine poroma, scalp*
B: Eccrine poroma, plantar
(Courtesy of Dr. Sophie M.
Worobec)
C: Cylindroma*
*Courtesy of Dr. Paul Getz

(Figure 5.4A, B)

Presents as erythematous papule, plaque or nodule with characteristic “moat” surrounding lesion; often on palm, sole, or scalp
Histology: well-circumscribed tumor appearing in lower part of epidermis and extending into dermis, cells consist of small cuboidal epithelial (“poroid”) cells which are more pale than normal keratinocytes (may be clear due to glycogen accumulation), small sweat ducts seen within tumor, sharp demarcation between poroid cells and surrounding keratinocytes