Association of Down's Syndrome and Testicular Cancer:

Constitutional inv(3) in myelodysplastic syndromes

The constitutional pericentric inversion on chromosome 3, inv(3), is rarely found in a normal population. The aim of our study was to investigate its possible link to hematologic malignancy. Chromosomes from bone marrow cells in 890 patients with hematologic disorders were analyzed with the Q-banding technique. Thirty-four patients had inv(3) (3.8%). In 241 patients with myelodysplastic syndromes the frequency was 6.2% as opposed to 2.9% in the remaining 649 patients (p=0.02). The increased frequency of inv(3) in patients with myelodysplastic syndromes indicates that inv(3) could be a risk factor for the development of the disease.

Testicular tumor in Down syndrome

A 33-year-old male patient with Down syndrome, who stayed in a welfare institution, visited our hospital due to left testicular enlargement. He was diagnosed as having a left testicular tumor and underwent radical inguinal orchiectomy. Preoperatively, serum level of beta-human chorionic gonadotrophin (beta-HCG) increased to 0.9 ng/mL (normal range <0.2 ng/mL). For the last 2 years after orchiectomy, the serum level of beta-HCG remained normal. Histopathological examination of specimen revealed a typical seminoma. It is currently thought that risk of developing leukemia in patients with Down syndrome is 20- to 30-fold higher than that in normal subjects. Furthermore, the incidence of testicular cancer as a complication other than leukemia is expected to increase because of the increasing postpubertal population with Down syndrome.