Hematopathology of the bone marrow in pediatric cutaneous mastocytosis. A study of 17 patients
Sixteen bone marrow aspirates and 15 trephine core biopsies from 17 children with cutaneous mastocytosis, of which 15 exhibited urticaria pigmentosa and 2 exhibited diffuse cutaneous mastocytosis, were evaluated for the presence of bone marrow-associated pathologic conditions. Eight bone marrow aspirates from 8 children and 23 trephine core bone marrow biopsies from 16 children who had had evaluation for hematologic abnormalities not associated with cutaneous mastocytosis served as a control population. Eosinophilia was a prominent finding in bone marrows of 9 of 17 patients who had cutaneous mastocytosis. Increased mast cell numbers in bone marrow aspirates were observed in 5 children with cutaneous mastocytosis (5 of 16) and in 2 of the control children (2 of 8). Examination of the trephine core bone marrow biopsies obtained from patients with cutaneous mastocytosis demonstrated focal perivascular and paratrabecular aggregates consisting of mast cells, eosinophils, and early myeloid cells in 10 of 15 individuals. Similar lesions were observed in trephine core bone marrow biopsies of 3 of 16 control patients. The focal mast cell lesions characteristic of adult systemic mastocytosis were not observed. The authors conclude that cutaneous mastocytosis in the pediatric age group is rarely associated with definitive bone marrow findings suggestive of systemic mast cell disease and that this observation is consistent with previous reports that cutaneous mastocytosis in the majority of pediatric cases resolves by adulthood.