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.
Hoffmann
Karl M
KM
Division of Pediatric Hematology/Oncology, Department of Pediatrics and Adolescent Medicine, Medical University Graz, Graz, Austria. hoffmaka@mac.com
Moser
Andrea
A
Lohse
Peter
P
Winkler
Andreas
A
Binder
Barbara
B
Sovinz
Petra
P
Lackner
Herwig
H
Schwinger
Wolfgang
W
Benesch
Martin
M
Urban
Christian
C
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