Nasopharyngeal angiofibroma: An APC-gene-associated tumor?

Nasopharyngeal angiofibromas are extremely rare, locally invasive tumors of unknown cause exclusively occurring in male adolescents. Recently, 6 cases have been reported in patients with familial adenomatous polyposis coli (G ardners syndrome). Mutations or allelic loss of the adenomatous polyposis c oli (APC) gene have therefore been implied in the pathogenesis of nasophary ngeal angiofibroma. The authors analyzed 11 cases of nasopharyngeal angiofi bromas from 9 male patients for mutations in the mutation cluster region an d allelic loss of the APC gene. Six were primary tumors; 2 first recurrence s; and 1, primary tumor with 2 recurrences. Direct sequence analysis was pe rformed on several overlapping polymerase chain reaction (PCR) products. De tection of allelic loss was performed by restriction length polymorphism an alysis at a polymorphic locus. No mutation was detected in 11 tumors of 9 d ifferent patients. None of the 9 informative (heterozygous) cases carried a n allelic loss. We conclude that alterations of the APC gene do not play a major role in the development of nasopharyngeal angiofibroma. The coinciden ce of nasopharyngeal angiofibromas and adenomatous polyposis coli in some f amilies implies the possibility that another gene in this: region might be responsible for the development of nasopharyngeal angiofibromas. HUM PATHOL 31:1411-1413. Copyright (C) 2000 by W.B. Saunders Company.