Pediatric-onset mastocytosis: a long term clinical follow-up and correlation with bone marrow histopathology.

Background: Pediatric onset mastocytosis usually presents as urticaria pigmentosa; and less often as diffuse cutaneous mastocytosis. While the literature indicates that disease often resolves, there has been a move to more aggressive therapy for mastocytosis early in life. We addressed the long term prognosis of pediatric-onset disease by examining 17 children with mastocytosis which we had reported on in 1989 [1].

Procedure: We successfully contacted 15 of these patients and data was collected regarding their clinical status. Original bone marrow specimens were re-stained, re-examined, and correlated with disease outcome using consensus criteria. Three of five patients with persistent disease underwent repeat bone marrow biopsies.

Results: There was complete regression of disease as defined by cutaneous findings and symptoms (clinical disease severity) in 10 of 15 patients (67%). Three patients had major (20%) and two had partial regression of disease (13%). Repeat marrow examinations on three patients with persistent disease documented systemic mastocytosis based on marrow findings in one patient who had partial regression of disease and was the only patient with initial morphologic evidence of systemic disease. Of the remaining two patients, one demonstrated partial regression and the other major regression of disease; and neither had evidence of systemic mastocytosis.

Conclusion: This study demonstrates that initial bone marrow biopsies were prognostic in that those without evidence of systemic disease experienced disease regression; and that the long term prognosis for children managed symptomatically with mastocytosis is highly encouraging.