GNAQ mutation in a patient with metastatic mucosal melanoma
1 Department of Medicine, Seoul National University College of Medicine, Seoul, Korea
2 Department of Melanoma Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
3 Department of Dermatopathology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
BMC Cancer 2014, 14:516 doi:10.1186/1471-2407-14-516Published: 16 July 2014
Mucosal melanomas represent about 1% of all melanoma cases and classically have a worse prognosis than cutaneous melanomas. Due to the rarity of mucosal melanomas, only limited clinical studies with metastatic mucosal melanoma are available. Mucosal melanomas most commonly contain mutations in the gene CKIT, and treatments have been investigated using targeted therapy for this gene. Mutations in mucosal melanoma are less common than in cutaneous or uveal melanomas and occur in descending order of frequency as: CKIT (20%), NRAS (5%) or BRAF (3%). Mutations in G-alpha proteins, which are associated with activation of the mitogen-activated protein kinase pathway, have not been reported in mucosal melanomas. These G-alpha protein mutations occur in the genes GNAQ and GNA11 and are seen at a high frequency in uveal melanomas, those melanomas that begin in the eye.
A 59-year old Caucasian male was diagnosed with a mucosal melanoma after evaluation for what was thought to be a hemorrhoid. Molecular analysis of the tumor revealed a GNAQ mutation. Ophthalmologic exam did not disclose a uveal melanoma.
Here we report, to our knowledge, the first known case of GNAQ mutation in a patient with metastatic mucosal melanoma.