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| {{WBRQuestion | | {{WBRQuestion |
| |QuestionAuthor=[[User:Gonzalo Romero|Gonzalo A. Romero, M.D.]] [mailto:gromero@wikidoc.org] | | |QuestionAuthor={{SSK}}(Reviewed by Serge Korjian) |
| |ExamType=USMLE Step 1 | | |ExamType=USMLE Step 1 |
| |MainCategory=Embryology, Pathology | | |MainCategory=Embryology, Pathology |
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| |MainCategory=Embryology, Pathology | | |MainCategory=Embryology, Pathology |
| |SubCategory=Reproductive | | |SubCategory=Reproductive |
| | |MainCategory=Embryology, Pathology |
| |MainCategory=Embryology, Pathology | | |MainCategory=Embryology, Pathology |
| |MainCategory=Embryology, Pathology | | |MainCategory=Embryology, Pathology |
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| |MainCategory=Embryology, Pathology | | |MainCategory=Embryology, Pathology |
| |SubCategory=Reproductive | | |SubCategory=Reproductive |
| |Prompt=A 10-year-old male teenager is concerned because one of his testis is not in his scrotum. They live in rural Pennsylvania, where health care is not readily available. He tells his mother because sometimes it is embarrassing for him when taking a shower with his swim team peers. He patient finally convinces his mother to take him to the doctor, who is very distant from where they live. The physician has a clinical suspicion just with the chief complaint. This patient is at risk of developing which of the following if left untreated?
| | |Explanation=transfusion reaction |
| |Explanation=This patient is presenting with [[cryptorchidism]], which is the abscence or undescend of one or both testis into the scrotum. | | |AnswerA=Hypersensitivity reaction against plasma proteins in transfused blood |
| '''Embryology:''' the testes remain high in the abdomen until the 7th month of gestation, when they move from the abdomen through the inguinal canals into the two sides of the scrotum. It has been proposed that movement occurs in two phases, under control of somewhat different factors. The first phase, movement across the abdomen to the entrance of the inguinal canal appears controlled (or at least greatly influenced) by anti-müllerian hormone (AMH). The second phase, in which the testes move through the inguinal canal into the scrotum, is dependent on androgens (most importantly testosterone). In rodents, androgens induce the genitofemoral nerve to release calcitonin gene-related peptide (CGRP), which produces rhythmic contractions of the gubernaculum, a ligament which connects the testis to the scrotum, but a similar mechanism has not been demonstrated in humans. Maldevelopment of the gubernaculum, or deficiency or insensitivity to either AMH or androgen therefore can prevent the testes from descending into the scrotum.
| | |AnswerB=Reaction due to cytokines from leukocytes in donor blood |
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| | |AnswerC=Host antibodies against antigens on donor RBCs |
| '''Physiologically''' it impairs spermatogenesis, because sperm cells develop at temperatures below 37C. They have normal testosterone levels, because Leydig cells are not affected by high temperatures, as supposed to the Sertoli cells which are affected. Lab tests reveal Prematurity decreased inhibin (by Sertoli cells), increased FSH and normal LH and testosterone. It is seen more frequent in premature infants. [[File:Testosterone Phys.png|center|800px]]
| | |AnswerD=Host antibodies against donor MHC antigens |
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| | |AnswerE=Host antibodies against donor IgA molecules |
| '''Cancer risk:''' about 1 in 500 men born with one or both testes undescended develop testicular cancer (seminoma), roughly a 4 to 40 fold increased risk. The risk is higher for intra-abdominal testes and lower for inguinal testes. The New England Journal of Medicine published in 2007 that orchidopexy performed before puberty resulted in a significantly reduced risk of testicular cancer than if done after puberty. (See https://www.ncbi.nlm.nih.gov/pubmed/17476009)
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| '''Educational Objective:''' </font></font>
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| # Cryptorchidism (undescended testis) is associated with an increased risk of developing testicular cancer, specifically germ cell tumors (seminoma).
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| '''References:''' First Aid 2012 reproductive chapter, page 575
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| |AnswerA=Germ cell tumor | |
| |AnswerAExp=<font color="Green">'''Correct.'''</font> Cryptorchidism increases the risk of developing [[germ cell tumors]]. Germ cell tumors represent 95 % of all testicular tumors, are frequently malignant.
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| |AnswerB=Inguinal hernia | |
| |AnswerBExp=<font color="red">'''Incorrect.'''</font> A [[hernia]] is a protrusion of peritoneum through an opening, frequently due to an area of weakness weakness.
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| |AnswerC=Varicocele | |
| |AnswerCExp=<font color="red">'''Incorrect.'''</font> [[Varicocele]] are dilated veins in the pampiniform plexus due to increased venous pressure. It is the most common cause of scrotal enlargement in adult males. Frequently presents on the ; most left side due to the increased resistance to flow from left spermatic vein drainage into the left renal vein. Long term it can produce infertility due to increased temperature. On physical examination it has a "bag of worms" appearance. It is diagnosed by ultrasound.
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| |AnswerD=Leydig cell tumor | |
| |AnswerDExp=<font color="red">'''Incorrect.'''</font> [[Leydig cell tumor]] They frequently secrete androgen resulting in gynecomastia in men, precocious puberty in boys. Macroscopically it presents as a golden brown colored tumor, and histologically it contains Reinke crystals.
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| |AnswerE=Sertoli cell tumor | |
| |AnswerEExp=<font color="red">'''Incorrect.'''</font> [[Sertoli Cell Tumor]] such as androblastoma arise from the sex cord stroma
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| |RightAnswer=A | | |RightAnswer=A |
| |WBRKeyword=cryptorchidism | | |WBRKeyword=cryptorchidism |
| |Approved=Yes | | |Approved=Yes |
| }} | | }} |