diagnostic criteria: mastocytosis
> 25% BM mast cell infiltrates, extracutaneous;
serum tryptase>20ng/ml;
KIT mutation/cytometry
Mastocytosis
pGx:
- Origin: mast cells derive CD34+ BM precursors, C KIT GENE (chr 4q12,CODON 816) activating mutations;
- Organs involved skin liver spleen GIT BM(systemic)
- mast cell mediators: preformed(histamine heparin, tryptase, chemotactic factors); newly
formed(PG, LT, PAF); Cytokines(TNFa, IL4-8, GMCSF) - triggers: exercise/heat/trauma; alcohol,NSAIDS, salicylate, narcotics,polymyxin B,GA(anaphylaxis;propofol safe)
Workup mastocytosis
- BX(no adrenaline) +stains Giemsa,leder, toluidine blue, CAE,
- ROS: fever LOW,+LN/HSP(US, CT LFT); NL:headache/cogitive;
- (symptomatic)- FBC(BM? eos-kit mutation c816), serum tryptase>20ng/ml;
- BM(immunophenotype, cytogenetic) GIT(endoscopy) bone pain/#(osteoporosisXray/bone scan); cardiac(CP/palpitation/syncope)
Rx mastocytosis
:avoid meds/triggers; post op 24H monitoring;
H1/H2 AH(GIT- cimetidine/ranitidine); sodiumcromoglycate;
systemic-refer hematology-chemo; standby epipen/pred
LCH new Cx:
1.Single(single/multi-site-skin, LN, bone) vs
multi-system(high-BM,liverspleen, lung, low risk,
CNS-risk -facial bones, sinuses, maxilla )
LCH Px
1- LC BM origin, clonal neoplastic, BRAFV600E mutation
2-S100/langerin/CD1a + EM- birbeck granules
LCH DDX
histiocytosis, mastocytosis,
seb derm, intertrigo, varicella,
Workup-LCH
1-skin biopsy,
2-solid organ/ ALL,
3-multisystem-marrow-hematologic, hepatosplenomegaly, pulmonary, renal, skeletal, CNS
LCH Poor prognostic-
multisystem, poor response 6w Rx 40-50% mortality
Rx LCH
Rx- skin only- topicals, PUVA,
multisystem-chemoRx, bone- curretage
WHO: mastocytosis
Cutaneous vs systemic(indolent, agressive);
mast cell sarcoma/leukemia/extracutaneous
