Case 139

A 32 year old female with a large ovary mass.

1. What is the chromosome findings commonly detected in this tumor?

A: 17p loss

B: Gain of 17q

C: isochromosome 12p

D: deletion of 3p

Answer

The correct answer is C. The diagnosis of dysgerminoma. Chromosome 12 abnormalities—primarily isochromosome 12p or 12p amplification—are found in about 80% of dysgerminomas. Additionally, KIT mutations (exon 17, codon 816) occur in 30–50% of cases, and KIT amplification is seen in 30%. In patients with gonadal dysgenesis, dysgerminomas may also develop in association with gonadoblastoma.

Case credit: UCSD pathology

Author: Wangpan Jackson Shi, MD

References: https://tumourclassification.iarc.who.int/chaptercontent/34/86