what % of testicular carcinoma is associated with crytorchidism?

Testicular Tumours: Epidemiology and Risk Factors Of all primary testicular tumours, 90-95% are germ cell tumours (seminoma and nonseminoma) More common in whites and individuals of higher socioeconomic class Slightly more common on the right side than on the left, which parallels the increased incidence of cryptorchidism on the right side. Of primary testicular tumours, 1-2% are bilateral, and about 50% of these tumours occur in men with a history of unilateral or bilateral cryptorchidism Seminoma is the most common germ cell tumour in bilateral primary testicular tumours, while malignant lymphoma is the most common bilateral tumour of the testis The strongest association has been with the cryptorchid testis. Approximately 7-10% of testicular tumours develop in patients who have a history of cryptorchidism; seminoma is the most common form of tumor these patients have. However, 5-10% of the testicular tumors occur in the contralateral, normally descended testis. The relative risk of malignancy is highest for the intraabdominal testis (1 in 20) and is significantly lower for the inguinal testis (1 in 80) Orchipexy doesnot alter the malignant potential of the cryptorchid testis; however, it does facilitate examination and tumor detection Ref: Smith 18th edition Pgno: 380