Chapter 16: Dermatologic diseases Flashcards
Ectodermal dysplasia
-‐ Condition in which 2+ ectodermal structures fail to develop (skin, hair, nails, teeth, sweat glds)
-‐ Hypohidrotic ectodermal dysplasia: chromosome xq12 (x-‐linked; most men)
-‐ HED: reduced sweat glands, heat intolerance, sparse hair, xerostomia, periocular hyperpigmentation, midface hypoplasia (with protuberant lips)
-‐ A/Oligo/hypodontia and teeth have typical shape (incisor with tapered crown, reduced molar)
-‐ Odonto-‐onychodermal dysplasia: involves all 4 ectodermal structures
-‐ Histo: skin shows decreased number of sweat glands and hair follicles.
White sponge nevus
-‐ AD, mutation in keratin 4 or 13 (expressed in spinal layer of epithelium).
-‐ White plaques cheeks, genital, nasal, anal mucosa
-‐ Histo: prominent hyperparak, acanthosis, clearing of cytoplasm of cells in spinous layer (~ leukoedema and HBID)
-‐ Perinuclear eosinophilic condensation: represents tangled masses of keratin tonofilaments
Hereditary benign intraepithelial dyskeratosis
-‐ AD, descendants of a triracial isolate from North Carolina
-‐ Oral lesions (~WSN) + eye lesions (thick plaques).
-‐ Prominent dyskeratosis, cell-‐within-‐a-‐cell phenomenon.
Pachyonychia congenita
-‐ Nails are lifted because of accumulation of keratin in bed. Nail loss eventually occurs.
-‐ Also palmar-‐plantar keratosis with callus formation, hyperhidrosis, blisters in soles of the feet
-‐ Type 1 (Jadassohn-‐Lewandowsky): oral white plaques (esp tongue); keratin 6a or 16 mut
-‐ Type 2 (Jackson-‐Lawler): neonatal teeth; keratin 6b or 17 mut. No oral white lesions.
-‐ Histo: hyperpara and acanthosis with perinuclear clearing of epithelial cells
Dyskeratosis congenita (Zinsser-‐Cole-‐Engman syndrome)
-‐ X-‐linked (mostly males). DKC1 mutation (disrupts telomerase).
-‐ Skin pigmentation with reticular pattern, dysplastic nails
-‐ Oral: bullae on tongue and buccal mucosa, which are followed by erosions and leukoplakias
-‐ Thrombocytopenia develops, followed by aplastic anemia
-‐ Tongue and cheek leukoplakias (30% SCC transformation in 10-‐30 years)
Xeroderma pigmentosum
-‐ AR trait, DNA-‐repair gene defect. Many cutaneous malignancies at a very early age (1000x ).
-‐ Actinic keratosis -‐> BCC -‐> SCC; melanoma in 5%
-‐ Oral SCC: lips, tip of tongue (very rare site)
Hereditary mucoepithelial dysplasia
-‐ AD trait. Epithelial cells do not develop normally (but no dysplasia is seen).
-‐ Alopecia (eyebrows and eyelashes), cataracts in childhood, impaired vision
-‐ Oral: striking fiery-‐red erythema of hard palate, and less on gingiva and tongue.
-‐ Nasal, conjunctival, vaginal and other mucosas also have fiery red apperance
-‐ Histo: epithelium with disorganized maturation. Cytoplasmic vacuoles (grayish inclusions)
Incontinentia pigmenti (Block-‐Sulzberger syndrome)
-‐ 37:1 F:M. Nemo gene mutation (x28). Lethal in males. Those who survive have klinefelter syndrome or mosaicism for NEMO (two populations of cell with different phenotype).
-‐ Eyes, skin, CNS
-‐ Stages: vesicular (4 mths-‐bullae on skin), verrucous (6 mths-‐plaques in limbs), hyperpigmentation (until puberty-‐swirling macules), and atrophy and depigmentation
-‐ Oral: oligodontia (hypodontia), delayed eruption, small and cone shaped teeth
Darier’s disease (keratosis follicularis, dyskeratosis follicularis, Darier-‐White disease)
-‐ Mutation in calcium pump. Lack of cohesion of epithelial cells.
-‐ Papules on trunk/scalp, excess keratin with foul odor, palmo-‐plantar keratosis, nail changes.
-‐ Oral: multiple papules on hard palate and alv mucosa that can coaslesce and give cobblestone.
-‐ Palate lesions ddx: inflammatory papillary hyperplasia and nicotine stomatitis
-‐ Histo: dyskeratosis, keratin plug overlying epithelium with a suprabasilar cleft.
-‐ Test tube rete ridges. Two types of dyskeratotic cells (corps rounds and grains)
Warty dyskeratoma (focal acantholytic dyskeratosis, follicular dyskeratoma, isolated Darier’s)
-‐ Solitary lesion, same location (oral) and histology as Darier’s (but otherwise unrelated)
-‐ Corps round or grains not prominent
Peutz-‐Jeghers syndrome
-‐ STK11 (LKB1) gene mutation on chromosome 19
-‐ Lesions involve periorificial areas (mouth, nose, anus, genital)
-‐ Intestinal obstruction due to intussusceptions (proximal segment “telescopes” into distal part)
-‐ Freckles in hands, perioral skin and oral mucosa; intestinal polyps (are not premalignant)
-‐ GI, breast; also pancreas, female genital tract, ovary cancer
Hereditary hemorrhagic telangiectasia (Osler-‐Weber-‐Rendu syndrome)
-‐ HHT1: ENG (endoglin) mutation, lung involvement (arteriovenus fistulas)
-‐ HHT2: ALK1 (ACVRL1) mutation, liver involvement (arteriovenus fistulas)
-‐ Oral telangiectasias: most vermillion lips, tongue, buccal mucosa
-‐ Dx (at least 3): recurrent spontaneous epistaxis; telangiectasias of mucosa and skin; AV malformations of lungs liver or CNS; family history HHT
-‐ DDx: CREST (positive for serum anticentromere antibodies)
Ehlers-‐Danlos syndrome
-‐ Ehlers-‐Danlos syndrome: production of abnormal collagen (collagen type 5 most common).
-‐ Joint laxity, easy bruising, marked skin elasticity and papyraceous scarring of skin
-‐ 7 types: classical-‐80% (severe/mild), hypermobility (no scarring), vascular (ecchymotic-‐ extensive bruising), kyphoscoliosis, arthrochalasis, dermatosparaxis, and other
-‐ Metenier sign: easy eversion of the upper eyelid in Ehlers-‐Danlos syndrome
-‐ Sapyraceous scarring: similar to crumpled cigarette paper, unusual healing upon minor injury
-‐ Type VIII: marked periodontal disease at young age
-‐ Gorlin sign: 50% patients can touch tip of nose with tongue (normal pop 10%)
Tuberous sclerosis (Epiloia, Bourneville-‐Pringle syndrome)
-‐ TSC1/2 mutation (chr 9/16). Mental retardation, seizures and facial angiofibromas.
-‐ Facial angiofibromas: multiple papules, most in nasolabial fold area
-‐ Ungual (periungual) fibromas: similar to angiofibromas, around or under margins of nails
-‐ Shagreen patches: hamartomas on skin of trunk
-‐ Ash-‐leaf spots: ovoid hypopigmentation (best seen with UV light) (3+)
-‐ “Tubers”: potato-‐like hamartomas of CNS (best seen in MRI)
-‐ Cardiac rhabdomyomas, angiomyolipomas of kidney, retinal hamartomas (major features)
-‐ Minor features: multiple enamel pits, gingival fibromas, desmoplastic fibromas, renal cysts and hamartomatous rectal polyps (minor features)
-‐ TS DX: 2 major or 1 major+2 minor findings
Multiple hamartomas syndrome (Cowden syndrome, PTEN-‐hamartoma tumor syndrome)
-‐ PTEN mutation (chromosome 10). High incidence of malignancies.
-‐ Similar findings in Proteus-‐like, Bannayan-‐Riley-‐Ruvalcaba and Lhermitte-‐Duclos syndromes
-‐ Skin trichilemmomas (aroud mouth, nose and ears), acral keratosis (warty growth on dorsal hand), palmar-‐plantar keratosis and cutaneous hemangiomas/neuromas/lipomas/xanthomas
-‐ Thyroid disease (follicular adenoma/ca), fibrocystic breast, breast CA, benign GI polyps
-‐ Oral: multiple fibromas on gingiva, dorsal tongue and buccal mucosa
-‐ Dx: 2 of trichilemmomas, oral papules, and acral keratosis
