| Describe the physiology of testosterone. | Produced by leydig cells under action of LH, intra-testicular testo 100* outside.
sertoli recieves testosterone and induces spermatogenesis
It has effects on brain (libido, confidence, memory), bone marrow (increase RBC count), bones (maintain BMD), skin (hair growth), sex organs (erectile and sperm), and muscles (growth) |
| What is male hypogonadism? | low serum testosterone (<300ng/dl) with 1 or more clinical symptom or sign.
Can be primary (testicular disorder) or secondary (pituitary) |
| What is primary hypogonadism? | Due to testicular disorder, low T high FSH and LH
Etiologies include genetics, infection (orchitis in mumps), tumor (leading to testes removal), anatomic defect (undescended), alcohol abuse (may be primary or secondary), aging, iatrogenic (radiation)... |
| What is hypogonadotropic hypogonadism? | HH, more common than primary, defecit in GnRH.
Low-normal or low T, FSH and LH
Etioloiges (hyperPRL (supresses them) pituitary lesion, cushing's, drug use (opiates), anabolic steroids, pitutary irradiation, iron overload, kallmann, idiopathic or genetic disorders (prader-willi) |
| What are the manifestations of pre-pubertal hypogonadism? | Eunuchoidal stature (الخصي المتنبي)
small testes, penis, lack of scrotal rugae and pigmentation, small prostate, no hair in face, pubes, infertility, gynecomastia, lack of libido, low BMD, low mass. |
| What are the Eunuchoid stature proportions? | Lower segment 2-5 cm > upper segment
Arm span 5cm >height |
| What is the effect of pre-pubertal HH on spermatogenesis? | Spermatogenesis won't occur spontaneously, so they need LH and FSH to compensate |
| What are the manifestations of post-pubertal hypogonadism? | Normal statue, penis size, testes (maybe slightly low), scrotum, prostate, voice.
Thinning of facial and pubic hair, infertiltiy, decreased libido, gynecomastia, mild anemia, hot flashes, lack of male baldness, erectile dysfunction |
| What is the treatment of hypogonadism? | Primary needs T replacement therapy only (maybe injection or get or transdermal)
Secondary (Acc to case, 21 year old man for example give LH (or hCG) and FSH, if 65 only testosterone)
Post-pubertal only give LH (testes developed already and spermatogenesis only needs T)
so if fertility not needed only T given |
| What is gynecomastia? | It is benign proliferation of glandular tissue in male breast, maybe unilateral or bilateral, diagnosed as palpable mass 0.5 cm diameter at least
(differs from pseudogynecomastia which is just fat) |
| What is the percentage of occurrence of gynecomastia? | Adolescence: 4-69% occurs alot in age 13014 due to hormonal changes (increased testo and thus increased estrogen)
middle-aged elderly men : 24% -65% affected above 50 |
| How is the pathogenesis of gynecomastia? | Decreased androgen production, increased estrogen, increased estrogen precursors, androgen receptor block, increased binding of androgens to sex-hormone binding globulins. |
| How is testosterone converted to estradiol? | By aromatase |
| What are the etiologies of gynecomastia? | Persistent pubertal (25%, at age of 13-14, if unresolved after 6 months to 2 years of onset)
Drugs (25%)
Idiopathic (25%).
Maybe cirrhosis, hypogonadism, testicular tumors, hyperthyroid, chronic renal insufficiency... |
| What is drug-induced gynecomastia? | Spironolactone (increase aromatization), antiandrogens (decrease androgen levels), other meds (CCB, H2-blockers Cimetidine) |
| What is cirrhotic caused gynecomastia? | 67% of pt with cirrhosis, increase androstendione and thus estradiol and estrone. |
| How does primary or secondary hypogonadism cause gynecomastia? | imbalance of testosterone and estrogen (in excess) |
| What are the testicular tumors causing gynecomastia? | Germ-cell tumor (hCG increase causing more aromatase activity)
Leydig cell tumor (increased estradiol and aromatase with testicular mass and loss of libido)
Sertoli cell tumor (feminization associated, excessive aromatase, convert androsten into estrone and testo into estradiol. |
| How can hyperthyroid cause gynecomastia? | Increased extraglandular aromatization and estradiol production |
| What is the course of action in case of gynecomastia? | If physiologic no need for evaluation...
We can see serum chemistry, testosterone, LH, estradiol levels (if pt with feminization), PRL, TSH if sus. |
