Dermatopathology (Part 4 of 4) Flashcards
(138 cards)
What is mycosis fungoides?
a cutaneous T-cell lymphoma of CD4 T helper cells in the skin
how does mycosis fungoides present? (age, where, what do they look like)
usually >40 yo with truncal lesions; scaly red-brown patches; raised scaling plaques (can be confused with psoriasis); fungating nodules
eczema like lesions in patients with mycosis fungoides usually means what?
it is in the early stages
multiple tumor nodules in patients with mycosis fungoides usually means what?
systemic spread
what is sezary syndrome?
seen in some cases of mycosis fungoides; erythroderma, diffuse erythema and scaling of entire body surface
what is the morphology of sezary cells?
markedly folded nuclear membrane CEREBRIFORM contour
what is the histological hallmark of cutaneous t cell lymphoma?
the presence of atypical cells that characteristically form band-like aggregates within the superficial dermis and invade the epidermis as single cells and small clusters known as Pautrier microabscesses
what is urticaria pigmentosa?
a cutaneous form of mastocytosis that primarily affects children
how does urticaria pigmentosa present?
multiple, widely distributed lesions, round-oval, red-brown, nonscaling papule and small plaques; around 10% of cases have systemic disease with mast cells infiltrating organs (mostly seen in adults)
what is solitary mastocytoma?
usually seen in young kids; pink-tan-brown nodule with possible blister formation
many of the signs and symptoms of mastocytosis occurs when mast cells degranulate- what happens when mast cells degranulate?
histamine and heparin are released
what are two signs that can be seen with mastocytosis?
darier sign and dermatographism
what is darier sign?
localized area of dermal edema and erythema (wheal) when skin is rubbed
what is dermatographism?
area of dermal edema resembling a hive, result of local stroking skin with pointed instrument
what are the systemic symptoms associated with mastocytosis?
pruritus and flushing or bone pain
why is there bone pain seen in mastocytosis?
mast cell infiltration causes it
what could be a clue that a patient has mastocytosis?
if they are presenting with osteoporosis in premenopausal women or in men –> due to excessive histamine release in the bone marrow
what causes mastocytosis?
a point mutation in KIT receptor tyrosine kinase–> leads to mast cell growth and survival
what is the histological appearance of mastocytosis?
spindle shaped and stellate mast cells, fibrosis, edema, and few eosinophils
what stain can you use to diagnose mastocytosis?
giemsa (shows metachromatic granules)
what is ichthyosis?
impaired epidermal maturation, hyperkeratosis that results in a clinically fish-like scale appearance
what are three examples of acute inflammatory dermatoses?
urticaria, acute eczematous dermatitis, erythema multiforme
generally speaking, what are acute inflammatory dermatoses?
acute lesions that last from days to weeks that are characterized by inflammatory infiltrates (usually lymphocytes and macrophages) NOT NEUTROPHILS
generally speaking, what are chronic inflammatory dermatoses?
chronic lesions persist for months to years and are often associated with changes in epidermal growth or dermal fibrosis