Background: Familial lentiginosis syndromes are characterized by a wide array of manifestations resulting from activation of molecular pathways which control growth, proliferation, and differentiation of a broad range of tissues. Familial gastrointestinal stromal tumors (GISTs) are often accompanied by additional features like hyperpigmentation, mastocytosis, and dysphagia. They have been described with mutations in c-kit (most commonly), platelet-derived growth factor receptor A, neurofibromatosis-1, and succinate dehydrogenase genes. Materials and Methods: We report on molecular characterization and tumor histopathology of two siblings in whom lentigines and café-au-lait macules were present along with multifocal GIST. Immuhistochemical analysis of CD34 and CD117 was performed on GIST biopsy samples from both siblings, while c-kit mutational analysis was done by PCR and direct sequencing on DNA from peripheral blood leukocytes of all family members and from paraffin-embedded gastric biopsy specimens of affected siblings. Results: Histopathology revealed positive expression of CD117 and CD34. Mutational analysis showed the germline c.1676T>C mutation in c-kit exon 11, (p.(Val559Ala)), in the peripheral blood of both siblings and a second exon 11 mutation, c.1669T>A (p.(Trp557Arg)) in the tumor biopsy of one of them. Initiation of imatinib treatment resulted in striking resolution of their hyperpigmentation and a stable gastrointestinal disease in one of them. Conclusions: A c-kit mutational test in familial GISTs is indicated before initiation of imatinib therapy, as it can help predict tumor response to treatment.
Familial gastrointestinal stromal tumors, lentigines, and café-au-lait macules associated with germline c-kit mutation treated with imatinib / D. Gupta, L. Chandrashekar, L. Larizza, E.A. Colombo, L. Fontana, C. Gervasini, D.M. Thappa, M. Rajappa, K.S. Rajendiran, G.S. Sreenath, V. Kate. - In: INTERNATIONAL JOURNAL OF DERMATOLOGY. - ISSN 0011-9059. - 56:2(2017 Feb), pp. 195-201.
|Titolo:||Familial gastrointestinal stromal tumors, lentigines, and café-au-lait macules associated with germline c-kit mutation treated with imatinib|
|Parole Chiave:||GIST; c-kit|
|Settore Scientifico Disciplinare:||Settore MED/03 - Genetica Medica|
|Data di pubblicazione:||feb-2017|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1111/ijd.13516|
|Appare nelle tipologie:||01 - Articolo su periodico|