CASE REPORT

A case of myoepithelial carcinoma displaying biallelic inactivation of the tumour suppressor gene APC in a patient with familial adenomatous polyposis

J Young¹, M Barker¹, T Robertson², S Nasioulas³, A Tannenberg⁴, R L Buttenshaw¹, N Knight⁵, J R Jass⁶ and B A Leggett¹

¹ Conjoint Gastroenterology Laboratory, Royal Brisbane Hospital Research Foundation Clinical Research Centre, Bancroft Centre, 300 Herston Road, Herston Q4029, Australia
² Department of Anatomical Pathology, Princess Alexandra Hospital, Ipswich Road, Woolloongabba Q4012, Australia
³ Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Parkville, VIC 3052, Australia
⁴ Department of Pathology, Mater Misericordiae Hospital, Raymond Terrace, South Brisbane Q4101, Australia
⁵ Queensland FAP Registry, Queensland Cancer Fund, 553 Gregory Terrace, Fortitude Valley Q 4006, Australia
⁶ Department of Pathology, University of Queensland, Herston Q4006, Australia

Correspondence to:
Correspondence to:
Dr J Young, Conjoint Gastroenterology Laboratory, Royal Brisbane Hospital Research Foundation Clinical Research Centre, Bancroft Centre, 300 Herston Road, Herston Q4029, Australia

Familial adenomatous polyposis (FAP) is an autosomal dominant disorder caused by mutation of the APC gene. It is characterised by the appearance of hundreds to thousands of colorectal adenomas in adolescence and the subsequent development of colorectal cancer. Various extracolonic malignancies are associated with FAP, including desmoids and neoplasms of the stomach, duodenum, pancreas, liver, and brain. We present a family affected by FAP with an exon 14 APC mutation displaying two rare extracolonic lesions, a hepatoblastoma and a myoepithelial carcinoma. The hepatoblastoma was found in a male patient aged 2 years. The second lesion, a myoepithelial carcinoma of the right cheek, was found in a female patient aged 14 years. Inactivation of the normal APC allele was demonstrated in this lesion by loss of heterozygosity analysis, thus implicating APC in the initiation or progression of this neoplasm. This is the first reported case of this lesion in a family affected by FAP.

Keywords: familial adenomatous polyposis; APC gene; loss of heterozygosity; myoepithelial carcinoma hepatoblastoma

Abbreviations: FAP, familial adenomatous polyposis; LOH, loss of heterozygosity

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?