title: An ultrastructural study of urticaria pigmentosa.
mesh_terms: D000293:Adolescent; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000648:ultrastructure; D008854:Microscopy, Electron; D014582:Urticaria Pigmentosa / Q000473:pathology*