Unexpected distribution of cKIT and BRAF mutations among southern Italian patients with sinonasal melanoma.

BACKGROUND

Racial and geographic factors seem to affect the incidence of cutaneous and mucosal melanoma.

OBJECTIVE

To investigate the occurrence of BRAF and cKIT impairments in patients with sinonasal melanoma in Southern Italy.

METHODS

Eleven sinonasal melanomas were screened for BRAF mutations and cKIT alterations by immunohistochemistry (CD117), fluorescence in situ hybridization and sequencing analyses.

RESULTS

A high prevalence (4/11; 36%) of BRAF mutations and lack of cKIT mutations were observed. Amplification of cKIT was found in 18% of cases; cKIT expression was detectable in 18% non-overlapping cases. No correlation between CD117 and cKIT alterations was observed. One (6%) cKIT and two (12%) BRAF mutations were detected in an additional series of 17 acral/mucosal melanomas from the same geographic areas.

CONCLUSION

Mutations of cKIT are infrequent in sinonasal melanoma in Southern Italy.