Most common tumor encountered undescended testes?

Ans. C. Seminoma. (Ref. Bailey and Love 26th/pg. 1378).Undescended testis# Testes that are absent from the scrotum after three months of age are unlikely to descend# Histological changes in the testis can be seen from one year of age# An incompletely descended testis tends to atrophy as puberty approaches# Boys with undescended testes are at greater risk of infertility, testicular malignancy (esp seminoma), hernia and testicular torsion.Retractile testis# Retractile testes should be differentiated from true undescended testes# Retractile testes are more common than true undescended testes# Retractile testes require no treatmentINCOMPLETELY DESCENDED TESTISDefinition: Incomplete descent of the testis occurs when the testis is arrested in some part of its normal path to the scrotum. An ectopic testis is a testis that is abnormally placed outside this path.Incidence: About 4 % of boys are bom with one or both testes incompletely descended. About two thirds of these reach the scrotum during the first three months of life, but full descent after that is uncommon. The incidence of testicular maldescent at the age of one year is around 1 %. In 10 % of unilateral cases, there is a family history.Pathology: The condition is more common on the right and is bilateral in 20 % of cases. In adults, secondary sexual characteristics are typically normal.The testis may be:# intra-abdominal; usually lying extraperitoneally just inside the internal inguinal ring;# intra-canalicular; it may or may not be palpable;# extra-canalicular; usually at the scrotal neck;# ectopic; the most common site is within the superficial inguinal pouch which lies just inferior and medial to the superficial inguinal ring. Other rarer ectopic sites include the femoral triangle, the root of the penis and perineum.Useful investigations include:# laparoscopy-theoptimummethodofvisualisingtheanatomy;# ultrasound scan - this has a limited role in detecting an inguinal testis in an obese boy;# hormonal-in cases of bilateral impalpable testes, the presence of testicular tissue can be confirmed by recording a rise in serum testosterone in response to intramuscular injections of human chorionic gonadotrophin; these boys require specialist endocrine review.Consequences:Infertility, Malignancy (The most common cancer is a seminoma and, as with fertility, it is unclear whether early orchidopexy reduces the risk of malignancy.), Hernia, Testicular torsion.# Rx: Orchidopexy: usually performed before the boy reaches 12 months of age in an attempt to prevent the consequences. Orchidectomy is often advised for the unilateral intra-abdominal testis, which cannot be corrected by orchidopexy because of the future risk of malignancy. In cases of bilateral intra-abdominal testes, microvascular transfer and staged orchidopexy are two options available to preserve the testes if the testicular vessels are too short to permit a single-stage orchidopexy.In undescended testis, seminoma is the malignany most likely to develop if at all. Seminomas are radiosensitive and excellent results have been obtained by irradiating stage 1 and stage 2 tumours. More recently, the tumour has been shown to be highly sensitive to cisplatin, which is already being used for patients with metastatic disease. Experts are divided as to whether patients with stage 1 disease should be treated with adjuvant chemotherapy.If there are no metastases, 95% of patients will be alive 5 years after orchidectomy and radiotherapy or chemotherapy.If there are metastases, the survival rate drops to 75%.