Characteristics of Adrenal Masses in Familial Adenomatous Polyposis

Adrenal masses are a known extraintestinal manifestation of familial adenomatous polyposis. However, the literature on this association is largely confined to case reports.

This study aimed to determine the characteristics of adrenal masses in familial adenomatous polyposis and their clinical significance, as well as to estimate their prevalence. Mutational analysis was conducted to determine if any potential genotype-phenotype correlations exist.

This is a retrospective cohort study.

Analysis included all patients meeting the criteria of classic familial adenomatous polyposis who were registered with the Familial Gastrointestinal Cancer Registry, a national Canadian database.

Appropriate imaging or autopsy reports were available in 311 registry patients. Patients with adrenal metastases were excluded.

Data collection included demographic data, mutation genotype, adrenal mass characteristics, surgical interventions and mortality.

The prevalence of adrenal masses was 16% (n = 48/311). The median age at diagnosis of adrenal mass was 45 years. The median diameter of adrenal mass at diagnosis was 1.7 cm (interquartile range, 1.4-3.0) with a median maximal diameter of 2.5 cm (interquartile range, 1.7-4.1) with median imaging follow-up of 48 months. The majority of adrenal masses were benign (97%, n = 61/63). Surgery was performed on 7 patients because of concerns for size, malignancy, or hormonal secretion. One adrenal-related death was due to an adrenocortical carcinoma. Mutation analysis did not identify any specific genotype-phenotype correlations.

There were incomplete or insufficient endocrinology data available in the registry to allow for the analysis of hormone secretion patterns.

Adrenal masses are approximately twice as prevalent in the familial adenomatous polyposis population as in previous studies of the general population. Nearly all mutations led to truncation of the APC gene; however, there was no genetic signature to help predict those at increased risk. The majority of adrenal lesions identified were of benign etiology; thus, an intensive management or surveillance strategy with imaging screening is likely unwarranted. See Video Abstract at http://links.lww.com/DCR/A507.