This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Male Genital Tract, Subject name: Pathology
[{'content': 'A 5-year-old boy is brought to the pediatrician for a physical examination prior to beginning elementary school. On examination, the boy has only one palpable testis in the scrotum. Fuher examination reveals a palpable mass in the left inguinal region. This condition is referred to as \nSelect and explain. \nA. Cryptorchidism., B. Hydrocele., C. Orchitis., D. Varicocele.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Only One palpable testes in scrotal sac and palpable mass in inguinal region is suggestive of Cryptorchidism. Cryptorchidism - It is a complete/paial failure of the intra-abdominal testes to descend into the scrotal sac and is associated with testicular dysfunction. - It is associted with increased incidence of germ cell tumors of testes, even if the testis is surgically moved from its ectopic location back to the scrotum. - Physical examination reveals only one palpable testes in Scrotum and there may be palpable mass in inguinal region. - Descent of testes occurs in two phases : 1. Transabdominal phase - During this phase ,the testes comes to lie within the lower abdomen or brim of the pelvis. This phase is regulated by mullerian inhibiting substance. 2. Inguinoscrotal Phase - In this phase the testes descend through the inguinal canal into the scrotum This phase is regulated by androgen-induced calcitonin gene-related peptide from the genitofemoral nerve. - The descent of testes may arrest anywhere in between the pathway but the most common site is in the inguinal canal - Histological changes : arrested germ cell development associated with marked hyalinization and thickening of the basement membrane of spermatic tubules = A hydrocele is a serous fluid collection in the scrotum. = Orchitis (inflammation of the testis) can result from bacterial or viral infection. = A varicocele results from dilation of the veins of the spermatic cord, and the term "bag of worms" aptly describes the abnormality.', 'role': 'assistant'}]