This study is being done to create a registry to help us learn more about germ cell tumors (GCT) and other testicular tumors. The registry will include people with these tumors and also relatives and unrelated people without these tumors. This study will help us learn more about the prevention, diagnosis, treatment and outcome of these tumors. Studying relatives of patients and people unrelated to patients with GCT and other testicular tumors will help us understand why some people get these tumors and why some people don't.

Inclusion Criteria:

Case Cohort

• Must be ≥ 18 years of age AND
• Must be an English-speaker AND
• Must have a diagnosis or suspicion of germ cell tumor and/or a testicular mass

Family Member Cohort

• Must be ≥ 18 years of age AND
• Must be an English-speaker AND
• Must be a blood relative of the proband. Family members of probands are eligible. These individuals need not have a diagnosis of GCT-TT, as they will be used for segregation analysis of suspected variants found in the proband.

Control Cohort

• Must be ≥ 18 years of age AND
• Must be an English-speaker AND
• Must not have a personal history of cancer, with the exception of non-melanoma skin cancer, AND
• Must not have a family history of germ cell tumor or testicular tumor AND
• Must not be a blood relative of controls enrolled in this study

Exclusion Criteria:

At MSKCC, the following outpatient clinics will be used to recruit GCT and testicular tumor cases and controls: Urology (Department of Surgery), Gynecologic Oncology (Department of Surgery) Clinical Genetics, Genitourinary Oncology (Department of Medicine), and Gynecologic Medical Oncology (Department of Medicine).