Case 41 - Discussion

	Eccrine Poroma
Clinical Futures
	Benign adnexal neoplasm, malignant counterpart is porocarcinoma; Can be of either eccrine or apocrine lineage; Poromas belong to the spectrum of acrospiromas, along with nodular hidradenomas, clear cell hidradenomas, dermal duct tumors, and hidroacanthoma simplex.
Gross Findings
Microscopic Findings
	Relatively sharp circumscription; Tumor cells: small cuboidal epithelial cells, compact eosinophilic cytoplasm with occasional cytoplasmic vacuoles, monomorphous ovoid nuclei and inconspicuous nucleoli; Areas of ductal differentiation: tubules lined by a dense eosinophilic cuticle; Highly vascularized and focally sclerotic stroma.
Subtypes
	Intraepidermal poroma (historically known as hidroacanthoma simplex) represents a form of poroma in which nests of cells with tubular differentiation are confined to the surface epidermis, with no evidence of dermal involvement. This pattern of poromas can sometimes cause confusion with other entities that may exhibit an intraepidermal pattern of growth, including seborrheic keratosis and melanocytic neoplasms. Juxtaepidermal poroma refers to a pattern of poroma in which nests and thick cords of cells are in continuity with the epidermis but also involve the superficial dermis. The intervening stroma is highly vascularized, as described above. Dermal poroma (historically referred to as dermal duct tumor) represents a pattern of poroma confined wholly to the dermis. Some intradermal poromas have relatively little stroma, while others display the highly vascularized stroma that is typical of superficial poromas.
Reference
	http://tray.dermatology.uiowa.edu/DIB/EccPor-01.htm
	http://www.emedicine.com/derm/topic112.htm