mastocytosis

proliferation of mast cells
seen in hematopoietic regions of skeleton
sclerotic bone lesions
- diffuse osteosclerosis
- discrete, irregular, sclerotic nodules
- rarely lytic lesions with densely sclerotic margins
mast cells elaborate histamine ==> flushing, tachycardia, nausea, diarrhea
pigmented, pruritic rash (urticaria pigmentosa)
hepatosplenomegaly, adenopathy
thrombocytopenia; increased or decreased WBCs