20 - 109 - APPENDAGE TUMORS OF THE SKIN Flashcards
ductal differentiation is most commonly observed in what type of appendage tumor
Eccrine Tumors

Eccrine Tumors

Apocrine Tumors

Follicular Tumors

Sebaceous Tumors

Genetic Syndromes Associated with Appendage Neoplasms

Eccrine Appendage Neoplasms


Hidradenoma is a solitary, indistinct dermal nodule

B, The tumor is a circumscribed, nonencapsulated, solid and cystic dermal neoplasm.
C, Hidradenoma is composed of clear cells and cells with ductal and glandular differentiation.

Eccrine poroma is an erythematous dermal nodule with an epidermal rim that often occurs on acral surfaces.


A, Cylindroma is a smooth, flesh-colored papule, often presenting on the head and neck

B, The tumor is a dermally based proliferation of islands of basaloid epithelium, arranged in a pattern similar to that seen in a jigsaw puzzle.
C, An eosinophilic zone of basement membrane material separates the interlocking nests of tumor cells. Within the tumor nests, central cells have vesicular nuclei and eosinophilic cytoplasm, while peripheral cells have round basophilic nuclei with scant cytoplasm.

Spiradenoma is a flesh-colored nodule

B, It is usually a multinodular nonencapsulated dermal tumor wherein the basaloid nodules resemble blue balls in the dermis.
C, The central tumor cells have vesicular nuclei and eosinophilic cytoplasm, and the peripheral cells have smaller, round, basophilic nuclei with scant cytoplasm.

Syringoma presents as multiple, small, flesh-colored papules, often in a periorbital distribution

B, The tumor is composed of a dermal proliferation of cords and nests of tumor cells in the upper dermis.
C, Small ductal structures are present in a sclerotic stroma forming tadpoleshaped and comma-shaped epithelial structures.
Summary of Immunohistochemical Stains in the Distinction between Squamous Cell Carcinoma and Select Appendage Neoplasms


A, Microcystic adnexal carcinoma is an infiltrative tumor composed of cords and cysts of varying sizes and shapes.
B, The tumor extends through the dermis to involve the subcutaneous fat.
C, Perineural invasion is often seen.
D, The tumor cells may be positive for CK7.

Apocrine Appendage Neoplasms


Hidrocystoma is a translucent papule, frequently seen in a periorbital distribution.




















