boards fodder Hyperplasias and Benign Neoplasms of Adnexal Origin By Kristy Charles, MD, and Emily Smith, MD Follicular Entities Clinical Presentation Pathology Associations & Notes Basaloid follicular Nonspecific skin- Strands of basaloid cells with • PTCH mutation hamartoma colored papule numerous epidermal connections. • The familial form is autosomal More pink than BCC with no cleft- dominant and associated with milia, ing. comedones, hyperpigmented pap- ules, hypotrichosis, hypohidrosis, and palmar pits. Dilated pore of Papule with central Large cystic follicle with small Winer pore on face of elderly squamous buds. Pilar sheath acanthoma has thicker projecting Pilar sheath acan- Papule with central fingers. thoma pore on upper lip of middle aged to elderly patient Trichofolliculoma Small, papule or nod- Multiple “baby” follicles empty- ule with tuft of hair ing into a central large “mother” at central pore on the follicle. face, scalp or upper trunk. Fibrofolliculoma Central follicle with radiating thin • Birt-Hogg-Dubé syndrome: Auto- Small, skin-colored epithelial strands in a fibrovascu- somal dominant, folliculin mutation to white papules on lar stroma. (Mtor pathway). Colonic polyposis, head, neck, or upper spontaneous pneumothorax, renal Trichodiscoma trunk. Fibrofolliculoma cut in a plane cell carcinoma, medullary thyroid that does not show epithelial carcinoma. strands. Only see fibrovascular stroma. Trichoblastoma Solitary, brown or Dermal basaloid nodules in scle- • #1 tumor to grow in a nevus seba- blue-black nodule on rotic stroma. Papillary mesenchy- ceous scalp. mal bodies. Trichoepithelioma Skin-colored papule(s) Islands of basaloid cells in the • Brooke-Spiegler syndrome and mul- on nose, upper lips or upper dermis within fibrous tiple familial trichoepitheliomas cheeks. stroma with horn cysts, cribriform • Rombo syndrome (Swiss-cheese) nodules, papillary mesenchymal bodies and calcifi- • Bazex-Dupré-Christol syndrome cations. Desmoplastic Solitary, firm, annular Infiltrative thin cords and nests • AKA sclerosing epithelial hamar- trichoepithelioma papule with central of basaloid cells in upper dermis. toma dell on upper cheek of Horn cysts and calcifications com- • Paisley tie differential: Desmoplas- Kristy Charles, young woman. mon. Red sclerotic CD34+ stroma. tic trichoepithelioma, microcystic MD, is PGY-4 at adnexal carcinoma (look for deep the University of infiltration), morpheaform/infiltrative BCC, syringoma. Michigan Trichoadenoma Non-specific skin-col- Multiple red doughnuts in the der- ored papule on face. mis (each ~ infundibulum). Often in pairs resembling eyeglasses. Pilomatricoma Solitary, skin-colored Large dermal ball with matrical • Derived from hair matrix cells or bluish nodule on (blue) differentiation, keratinize to • Beta-catenin mutation (Wnt path- head, neck, or proxi- form shadow cells. Often calcify way) mal upper extremities or form bone. in childhood. “Tent • Conditions with multiple: Gardner sign” with stretching. syndrome, myotonic dystrophy, Rubinstein-Taybi syndrome, Turner syndrome, Trisomy 9, Sarcoidosis, HIV, Sotos syndrome. Emily Smith, Trichilemmoma Skin-colored, verru- Lobular epidermal prolifera- • Cowden syndrome (multiple hamar- MD, is a cous papule. tion of PAS-positive clear cells. toma syndrome): Autosomal domi- dermatopathology Peripheral palisading and thick nant, PTEN mutation. Oral papillo- fellow at the glassy eosinophilic basement mas, acral palmoplantar keratoses, University of membrane (eyeliner sign). sclerotic fibromas, increased risk for breast, follicular thyroid and endo- Michigan metrial cancers. p. 1 • Spring 2017 www.aad.org/DIR boards fodder Hyperplasias and Benign Neoplasms of Adnexal Origin (cont.) By Kristy Charles, MD, and Emily Smith, MD Follicular Entities Clinical Presentation Pathology Associations & Notes Tumor of follicular Solitary, small, kera- Plate-like horizontal epidermal • AKA isthmicoma due to isthmic infundibulum totic papule on head proliferation in papillary dermis. origin. or neck in adult. Isthmic differentiation. Proliferating Firm, lobulated nodule “Rolls and scrolls.” May form new • With loss of p53 may become a trichilemmal cyst on scalp of elderly cysts in confines of mother cyst. malignant proliferating trichilemmal woman. cyst. Eccrine Entities Clinical Presentation Pathology Associations & Notes Eccrine Smooth, translucent, Simple cyst lined by columnar or • Multiple in periorbital region: ecto- hidrocystoma flesh-colored to bluish cuboidal cells. dermal dysplasia. papule on head and • Multiple in general: warm climates, neck. hyperhidrosis, Graves’ disease. Syringoma Numerous small, Paisley-tie pattern of tadpole • Eruptive: Adolescent females, skin flesh-colored or yel- shaped ducts. types V and VI. Located on anterior lowish papules, most neck, chest, trunk, axillae, upper common on lower medial arms, and/or periumbilical eyelid. region. • Clear cell variant in diabetes. Poroma Slow-growing, flesh- Epidermal proliferation of monot- Variants: colored or red and onous cells with interspersed • Eccrine poroma ulcerated, exophytic ducts lined by eosinophilic cuticle. papule with epidermal May look like SK at low power. • Hidroacanthoma simplex (only epi- collarette, most often dermis) on palms/soles. Can • Dermal duct tumor (only dermis) be mistaken for pyo- genic granuloma. • Syringofibroadenoma (see row below) Syringofibroadenoma Variable presenta- Multiple thin anastomosing cords • Schöpf-Schulz-Passarge syndrome: tion. Most common on of benign epithelial cells within Autosomal recessive or sporadic, lower extremities. dermis. Prominent loose fibrovas- Wnt10A mutation. Apocrine hidrocy- cular-myxoid stroma. tomas, PPK, hypohidrosis, hypodon- tia, hypotrichosis, nail dystrophy, syringofibroadneomas • Clouston syndrome: Autosomal dominant, GJB6 (connexin 30). Hypo- trichosis, nail dystrophy, PPK, men- tal retardation. Spiradenoma Solitary, 1-2 cm, red- Large, round dermal islands of • Brooke-Spiegler syndrome: Autoso- brown, deep-seated blue cells peppered with black mal dominant, CYLD mutation (NF- nodule. Can be pain- lymphocytes and eosinophilic hya- kB pathway). Multiple cylindromas, ful. line droplets. spiradenomas, trichoepitheliomas • Painful tumors: BANGLE – blue rubber bleb nevus, angiolipoma, neuroma, glomus tumor, leiomyoma, eccrine spiradenoma. Nodular Slow-growing, firm, Well-circumscribed, non- • Features of eccrine and apocrine hidradenoma flesh- colored or red encapsulated solid-cystic nodular origin to blue, solid or cystic dermal lesion. Cuboidal cells nodule. admixed with clear cells and cuti- cle lined ducts. Bright red zones of basement membrane zone reduplication around vessels. Chondroid Firm nodule on head Circumscribed dermal nodule • AKA mixed tumor syringoma or neck. Commonly with epithelial cells in cords, • Analogous pleomorphic adenoma of mistaken for cyst. ducts or tubules in a myxoid- salivary gland cartilaginous stroma. p. 2 • Spring 2017 www.aad.org/DIR boards fodder Hyperplasias and Benign Neoplasms of Adnexal Origin (cont.) By Kristy Charles, MD, and Emily Smith, MD Apocrine Entities Clinical Presentation Pathology Associations & Notes Apocrine Smooth, translucent, Similar to eccrine hidrocystomas • Schöpf-Schulz-Passarge syndrome hidrocystoma flesh-colored to bluish but with decapitation secretion. (see above) papule in periorbital region. Erosive Unilateral, erythema- Endophytic proliferation of tubular adenomatosis of tous, eroded, crusted structures in the dermis with ver- the nipple papule of the nipple in rucous or ulcerated surface. No middle-aged women. atypia or necrosis. Associated with ulcer- ation and serosan- guineous discharge. Hidradenoma Small, unilateral, Dermal blue solid-cystic nodule • AKA papillary hidradenoma papilliferum (HPAP) flesh-colored sub- with maze-like internal structure cutaneous nodule that “looks like one can HIDe in on female vulva. it.” No epidermal connection (ver- Associated with pain sus SCAP). or discharge. Syringocystadenoma Asymptomatic, firm, Opens to the surface (versus • Likely both apocrine and eccrine papilliferum pink papule usually HPAP). Blue papillary fronds (~ origin (SCAP) on scalp. Increased villi) extend upward into clear • Usually in association with another size with papillated, spaces with decapitation secre- adnexal tumor; 40% arise in nevus hyperkeratotic surface tion. Prominent plasma cells sebaceous (2nd most common at puberty. present (versus HPAP). tumor). • PTCH and p16 mutations • Goltz syndrome: X-linked dominant, PORCN mutation (Wnt pathway). Fat herniation, osteopathia striata, coloboma, alopecia, lobster claw deformity. Cylindroma Slow-growing, pink, Islands of blue cells outlined • “Turban tumors” firm, hairless nodules by thick, eosinophilic basement on the scalp. membrane. Arranged in “jigsaw • CYLD mutation spectrum: Brooke- puzzle” pattern. Spiegler syndrome and Familial Cylindromatosis Sebaceous Entities Clinical Presentation Pathology Associations & Notes Nevus sebaceous Linear, hairless, yel- “Broad, bald, bumpy & bubbly.” • Associated mutations HRAS, KRAS low, waxy, verrucous Multiple small sebaceous glands • Nevus sebaceous syndrome (Schim- plaque on scalp. located high in dermis with fre- melpenning or Organoid-nevus syn- Becomes more promi- quent apocrine glands. Absence of drome): Extensive, congenital nevus nent at puberty. hair follicles is a strong clue. sebaceous – typically linear. Ocular, cerebral, skeletal, cardiovascular and urologic defects. Sebaceous Smooth, well-circum- Sebaceous