Derm Path I Flashcards
What is the role of the stratum basale?
Keratinocyte stem cells
What is the role of the stratum spinosum?
Production of keratin
What is the role of hte stratum granulosum?
Processes keratin to make it soft
Nails don’t have stratum granulosum –> why it’s not soft
What is the role of the stratum lucidem and where in the body is it found?
Protective against shear force
Found in thick skin- in the palms and soles of feet
What is the role of the stratum corneum?
Adds strength- primarily dead cells- deals with water balance as well
What do Merkel cells look like under a microscope?
Nothing - you can’t see them!
What cells are disordered in ichthyosis?
Keratinocytes
What is the path of ichthyosis?
Defective desquamation leads to build up of compacted scale
Which enzyme is deficient in x-linked ichthyosis?
Steroid sulfatase, responsible for “breaking down the concrete between the bricks so the bricks can slough off”
What is orthokeratosis?
Fish-like scales - seen in ichthyosis
“barnacles of age” are the dominant feature of what derm condition?
Seborrheic keratosis
What is the clinical morphology of seborrheic keratosis?
“Stuck on” verrucous waxy appearing brown papules or plaques anywhere on the skin except the palms and soles
What is “papillomatosis”
The Bart Simpson sign-
What is the major difference between seborrheic keratosis and melanoma?
Lack of atypia in sebhorreic
Flat base “string sign” present in sebhorreic – line in which the hyperplasia does not invade into the dermis
Which disease process is described by poorly defined, hyperpigmented verrucous plaques with a velvety scale commonly found in the creases of the axilla and neck?
Acanthosis nigricans
Which layer of the skin undergoes hyperpigmentation in acanthosis nigricans?
basal layer
What two histologic findings are found both acanthosis nigricans and seborrheic nigricans?
Hyperkeratosis and papillomatosis
Which two histologic findings differentiate seborrheic keratosis from acanthosis nigricans?
Shoe-string sign
Pseudo horn cysts
What is the Leser-Trelat sign?
Eruption of MANY many seborrheic keratosis spots
Indicative of a paraneoplastic syndrome (predominantly GI)
Differentiate the age of onset of benign type vs malignant type of acanthosis nigricans
Benign: childhood (usually caused by obesity/endocrine or hereditary)
Malignant: middle age and up