Flashcards in Mastocytosis Deck (15)
A mitogen that plays a big role in mast cell growth and migration
Neoplasms of mast cells usually present as...
benign cutaneous lesions in kids (the most common is “urticaria pigmentosa”, aka itchy pigmented skin lesions).
When they OCCASIONALLY spread beyond skin...
they release lots of histamine and other mediators, causing systemic symptoms (flushing, abdominal pain, tachycardia, hypotension) that can can really confuse the clinician.
most common site of systemic involvement
(but can also involve other organs...i.e. spleen, liver, lymph nodes)
Important diagnostic indicator
serum tryptase level
Fusion protein and tyrosine kinase involved...
FIP1L1-PDGFRB (4 partners identified)
Some respond to imatinib!!
Morphology (bone marrow)
Bland looking cells, round/spindle shaped
Percent associated w second hematologic malignancy
Either cKIT mutants OR PDGFRA activation (FIP1) translocation
Variable and Confusing
Aggregates of bland looking cells
sometimes w/ eosinophilia
CD25 usually positive
depends on complex subclassification scheme
Aggregates of mast cells can be subtle an bland looking, so...
Immunostains are key!