Table 7. Recommended Screening Intervals by Spigelman Stage continued...
Adrenal tumors have been reported in FAP patients, and one study demonstrated LOH in an adrenocortical carcinoma in an FAP patient. In a study of 162 FAP patients who underwent abdominal CT for evaluation of intra-abdominal desmoid tumors, 15 patients (11 females) were found to have adrenal tumors. Of these, two had symptoms attributable to cortisol hypersecretion. Three of these patients underwent subsequent surgery and were found to have adrenocortical carcinoma, bilateral nodular hyperplasia, or adrenocortical adenoma. The prevalence of an unexpected adrenal neoplasia in this cohort was 7.4%, which compares with a prevalence of 0.6% to 3.4% (P < .001) in non-FAP patients. No molecular genetic analyses were provided for the tumors resected in this series.
Hepatoblastoma is a rare, rapidly progressive, and usually fatal childhood malignancy that, if confined to the liver, can be cured by radical surgical resection. Multiple cases of hepatoblastoma have been described in children with an APC mutation.[116,117,118,119,120,121,122,123,124,125] Some series have also demonstrated LOH of APC in these tumors.[117,119,126] No specific genotype-phenotype correlations have been identified in FAP patients with hepatoblastoma. Although lacking level 1 evidence, a consensus panel has recommended abdominal examination, abdominal ultrasound, and measurement of serum alpha fetoprotein every 3 to 6 months for the first 5 years of life in children with a predisposition to FAP.[92,128]
The constellation of CRC and brain tumors has been referred to as Turcot syndrome; however, Turcot syndrome is molecularly heterogeneous. Molecular studies have demonstrated that colon polyposis and medulloblastoma are associated with mutations in APC, while colon cancer and glioblastoma are associated with mutations in mismatch repair (MMR) genes.
There are several reports of other extracolonic tumors associated with FAP, but whether these are simply coincidence or actually share a common molecular genetic origin with the colonic tumors is not always evident. Some of these reports have demonstrated LOH or a mutation of the wild-type APC allele in extracolonic tumors in FAP patients, which strengthens the argument for their inclusion in the FAP syndrome.