Successful treatment of progressive cutaneous mastocytosis with imatinib in a 2-year-old boy carrying a somatic KIT mutation.
Cutaneous mastocytosis (CM) in children is a usually benign skin disorder caused by mast cell proliferation. Progressive disease leading to systemic involvement and fatal outcomes has been described. C-kit receptor mutations have been identified as causative for CM, some of which potentially respond to imatinib treatment as described for patients with systemic mastocytosis. We report successful therapy of progressive CM with imatinib in a 23-month-old boy. KIT gene analysis revealed not only a somatic deletion of codon 419 in exon 8 (c.1255_1257delGAC) which responds to imatinib therapy, but also a novel germ line p. Ser840Asn substitution encoded by exon 18 in the c-kit kinase domain. Family history suggests this exchange does not affect receptor function or cause disease. Imatinib therapy was well tolerated, stopped symptoms and disease progression, and appeared to shorten the course of the disease. Imatinib could possibly represent a novel therapeutic option in patients with progressive CM.
Division of Pediatric Hematology/Oncology, Department of Pediatrics and Adolescent Medicine, Medical University Graz, Graz, Austria. hoffmaka@mac.com
Karl M
KM
Hoffmann
Andrea
A
Moser
Peter
P
Lohse
Andreas
A
Winkler
Barbara
B
Binder
Petra
P
Sovinz
Herwig
H
Lackner
Wolfgang
W
Schwinger
Martin
M
Benesch
Christian
C
Urban
D019943:Amino Acid Substitution; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D002675:Child, Preschool; D018095:Germ-Line Mutation; D006801:Humans; D000068877:Imatinib Mesylate; D007223:Infant; D008297:Male; D034701:Mastocytosis, Cutaneous / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D010879:Piperazines / Q000627:therapeutic use*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D011743:Pyrimidines / Q000627:therapeutic use*; D017384:Sequence Deletion
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D019009:Proto-Oncogene Proteins c-kit