Benign epidermal tumors Flashcards
When do SK’s start?
4th decade of life usually
Genetic mutations associated with seborrheic keratoses?
Activating mutations in FGFR3 and PIK3CA
Where don’t SK’s form?
Mucous membranes, palms and soles
Are HPV viruses located in SK?
SK’s in the genital region are likely condyloma acuminatum. Recommend bx. -HPV has been detected frequently in SK of the groin
What conditions are associated w/ an abrupt appearance/increase in # of SK”s followed by regression when condition resolves
Pregnancy, co-existing inflammatory dermatoses (in particular erythroderma), and malignancy.
What cancers are associated with leser-trelat
Adenocarcinoma of the breast, colon, gastric and lymphoma
Where is leser-trelat usually seen?
On the back, can have itching, can have malignant acanthosis nigracans
What is a lichenoid keratosis?
Inflammation/regression of benign lentigo, sk, or ak
What do lichenoid keratoses look like clinically?
Pink papule, scaly, most common on the forearm and upper chest (mimics BCC or SCCIS)
What is a path difference between deratosis papulosa nigra and SK?
DPN is like an SK w/o the pseudohorn cysts
What virus is stucco keratosis associated with?
HPV-23b
How can you get rid of stucco keratosis?
Suggest keratolytics
Varients of porokeratosis?
- Porokeratosis of Mibelli
- Disseminated superficial actinic porokeratosis
- Linear porokeratosis
- Punctate porokeratosis
- Porokeratosis palmaris, plantaris, et disseminata
- Porokeratotic eccrine ostial and dermal duct nevus
What are the risk factors for porokeratosis that increase the risk of complications, such as malignant transformation?
Length of time w/ lesion, older pts, linear variants
Which type of porokeratosis has the lowest risk of malignant change
DSAP
What is Flegel’s dz?
Hyperkeratosis lenticularis perstans
- Rare AD, mid to late adulthood -asymptomatic disc-shaped keratotic papules on distal extremities
- Electron microscopy: absent or altered Odland bodies (lamellar granules) which leads to hyperkeratosis
Should you bx cutaneous horns?
Yes, in situ or invasive SCC present in up to 20% of lesions.
Most common location of clear cell acanthoma?
Solitary papule or plaque on leg.
- Lesions are blanchabe, erythematous, and discrete; they may have attached wafer-like scale at the periphery
- String of pears of vessels in clear cell acanthoma
What is the cause of the clear cells in clear cell acanthoma?
Increased glycogen in the cell accounts for their clear appearance and is due to a defect in phosphorylase
What is a key feature of IFK compared to SK?
Squamous eddies. These are signs that skin has been irritated.
What lesion looks like a single spot of darier?
Warty dyskeratoma
Histology of warty dyskeratoma?
Invaginated cup with dyskeratosis and acantholysis
What genes are associated with epidermal nevus?
FGFR3, PIK3CA, HRAS>NRAS>KRAS
DDX for comedones on face?
Favre racouchot (old sun-damaged skin, lateral cheeks) , chloracne, nevus comedonicus
What do you treat confluent and reticulated papillomatosis with?
Oral minocycline (50% success) then could do retinoids
Distribution of SK’s usually?
Sun-exposed areas, not as apparent on double-clothed areas (areas underwear covers)
Clinical presentation of porokeratosis of Mibelli?
In kids infancy or childhood usually on distal extremity often several cm in diameter
Clinical presentation of disseminated superficial actinic porokeratosis?
Onset in middle age, F>M; numerous brownish-red macules w/ keratotic borders on sun-exposed areas (m/c is the legs, rare on the face)
Immunosuppression is a risk factor
Clinical presentation of linear porokeratosis?
Streaks along the lines of Blaschko: arise during infancy or childhood
Highest risk of progressing to SCC
Clinical presentation of punctate porokeratosis?
Onset in adolescence; 1-2mm “seed-like” papules on palms and soles
When do epidermal nevi typically occur?
In the first year of life
What is the presentation of porokeratosis palmaris, plantaris, et disseminata?
Onset is in childhood/adolescence
- AD genodermatosis
- Occurs on the palms/soles initially as uniform hyperkeratotic lesions that look like poro and then involve other areas that are non-sun exposed
Clinical presentation of porokeratosis ptychotropica?
Red to brown papules and verrucous plaques in the intergluteal cleft on the buttocks
What is the clinical description of epidermal nevi?
Papillomatous, pigmented, linear plaques along Blaschko’s lines
What are the 4 variants of epidermal nevus?
Nevus unius lateris: extensive b/l lesions on trunk
Inflammatory linear verrucous epidermal nevus (ILVEN): Along lines of Blaschkow without neurologic defects
Epidermal nevus syndrome: Schimmelpenning syndrome: a/w developmental abnormalitiees (neuro and MSK)
What is the clinical presentation of nevus comedonicus?
A linear array of comedones on the face>trunk (happens in childhood but worsens during puberty)
What genetic abnormalities are involved in nevus comedonicus?
FGFR2 mutations: Alagille syndrome, apert syndrome, cardiocranila syndrome, and Crouzon syndrome
