There are no established criteria for the diagnosis of gonadoblastoma. It is often found during a workup for ambiguous genitalia in infancy or sexual developmental disorder in puberty. Chromosomal analysis plays the most beneficial role in the diagnosis of conditions associated with gonadoblastoma. However, sometimes the Y chromosome materials are present in molecular level and cannot be diagnosed karyotypically. In theses individuals, molecular analysis of chromosomes using polymerase chain reaction (PCR) and/or fluorescence in situ hybridization (FISH) may be helpful.

There is no single diagnostic study of choice for the diagnosis of gonadoblastoma, but gonadoblastoma can be diagnosed based on the karyotype analysis and imaging studies.

The karyotype analysis must be performed:^[1]

• As the first step of diagnosis, when the patient presents with ambiguous genitalia or abnormal sexual developmental disorders.
• In presence of Y chromosomal content in female phenotype individuals.
• In male phenotype individuals, suspected of intersex disorder. The regular ultrasound imaging may help in the diagnosis.
• Although helpful, a normal karyotype analysis can not exclude the presence of Y chromosomal content in molecular level, but the regular usage of molecular studies such as polymerase chain reaction (PCR) and/or fluorescence in situ hybridization (FISH) for this purpose has undetermined clinical significance.

Although very uncommon, gonadoblastoma may affect genotypically normal individuals as well.

• In this setting, ultrasound imaging studies in individuals complaining of testicular/lower abdominal mass or discomfort may reveal the presence of the tumor.