A t(12;17) in an extraorbital giant cell angiofibroma.

We report a case of a 43-year-old male who presented with a large soft-tissue neck mass 7 years ago. A diagnosis of giant cell angiofibroma (GCA) was made on the basis of light microscopy and immunohistochemical studies. Chromosome analysis showed a male karyotype with t(12;17)(q15;q23),del(18)(q21) in all 20 cells analyzed. This cytogenetic abnormality in GCA is different from the t(17;22)(q22;q13) found in related lesions, such as giant cell fibroblastoma and solitary fibrous tumor, none of which has a specific chromosomal abnormality. Our case is the second case of GCA with chromosomal aberrations. To the best of our knowledge, this is the first case of GCA with t(12;17) occurring as an extra-orbital mass. 2006 Elsevier Inc. All rights reserved.