Frequency of gonadal tumours in complete androgen insensitivity syndrome (CAIS): A retrospective case-series analysis

BACKGROUND

Complete androgen insensitivity syndrome (CAIS) is an X-linked recessive disorder of sex development (DSD) where affected individuals are phenotypically female, but have an XY karyotype and testes. The risk of gonadal tumour development in CAIS may increase with age; incidence rates have been reported to be 0.8-22% in patients who have retained their gonads into adulthood. Consequently, gonadectomy has been recommended either during childhood or after puberty is complete, although there is no consensus on the optimal timing for this procedure.

OBJECTIVE AND HYPOTHESES

To establish the frequency of histological abnormalities in CAIS in relation to the age at gonadectomy.

METHOD

Data were collected from the Cambridge DSD database on patients with CAIS (n = 225; age range 3-88 years) who had undergone gonadectomy, and their age of gonadectomy, gonadal histology and immunohistochemistry.

RESULTS

Evaluable data were obtained from 133 patients. Median age at gonadectomy was 14.0 years (range: 18 days-68 years). Pubertal status was: prepuberty, n = 62; postpuberty, n = 68. Thirteen cases were aged >20 years at gonadectomy. The pattern of histology is summarised in the Summary table.

DISCUSSION

In this large case series of CAIS patients who had undergone gonadectomy, while the combined malignant and premalignant gonadal histology prevalence was 6.0%, the findings confirm the low occurrence of gonadal malignancy in CAIS, with a frequency of 1.5%. The two cases of malignancy were postpubertal. Germ cell neoplasia in situ (GCNIS) was observed in six cases, of which one occurred prepuberty and five postpuberty. The study highlighted difficulties in diagnosis of GCNIS and the need for histological analysis in expert centres.

CONCLUSION

The results support the current recommendation that gonads in CAIS can be retained until early adulthood. The small number of individuals with gonadectomy after age 20 years do not allow firm conclusion regarding later adulthood. Therefore, it is recommended that the option of gonadectomy be discussed in adulthood. Some form of regular surveillance of the gonads is then recommended, although none of the available options are ideal.

The Long-Term Outcome of Boys With Partial Androgen Insensitivity Syndrome and a Mutation in the Androgen Receptor Gene

BACKGROUND

In boys with suspected partial androgen insensitivity syndrome (PAIS), systematic evidence that supports the long-term prognostic value of identifying a mutation in the androgen receptor gene (AR) is lacking.

OBJECTIVE

To assess the clinical characteristics and long-term outcomes in young men with suspected PAIS in relation to the results of AR analysis.

METHODS

Through the International Disorders of Sex Development Registry, clinical information was gathered on young men suspected of having PAIS (n = 52) who presented before the age of 16 years and had genetic analysis of AR.

RESULTS

The median ages at presentation and at the time of the study were 1 month (range, 1 day to 16 years) and 22 years (range, 16 to 52 years), respectively. Of the cohort, 29 men (56%) had 20 different AR mutations reported. At diagnosis, the median external masculinization scores were 7 and 6 in cases with and without AR mutation, respectively (P = .9), and median current external masculinization scores were 9 and 10, respectively (P = .28). Thirty-five men (67%) required at least one surgical procedure, and those with a mutation were more likely to require multiple surgeries for hypospadias (P = .004). All cases with an AR mutation had gynecomastia, compared to 9% of those without an AR mutation. Of the six men who had a mastectomy, five (83%) had an AR mutation.

CONCLUSIONS

Boys with genetically confirmed PAIS are likely to have a poorer clinical outcome than those with XY DSD, with normal T synthesis, and without an identifiable AR mutation. Routine genetic analysis of AR to confirm PAIS informs long-term prognosis and management.