Thursday 17 June 2004
systemic mastocytosis : 6/M urticaria, Darier sign+; Metachromatic staining of granules by Giemsa.
TMEP (telangiectasia macularis eruptiva perstans)
DERMATOPATHOLOGY: First 3 variants have perivascular or diffuse mast cells within the upper dermis with occasional subepidermal bulla formation. TMEP has telangiectatic vessels with increased perivascular mast cells (>10 mast cells per 40x field). Mast cells are highlighted with Giemsa or toluidine blue special stains. Immunohistochemistry with CD117 antibodies may also be used.
DIFFERENTIAL: collections of mast cells may resemble nevus cells, histiocytes, Langerhans cells, and leukemic infiltrates