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OVARYOVARY
Anatomy& PhysiologyThe mature ovaries are paired nodular
structures 2,5-5*2*1 cmThe two major functions of the adult ovary:1) The synthesis and secretion of sex steroids2) The release of a mature ovum every 28-
30daysnormally progress in concert with one another
and are closely interrelatedPhysiology of the menstrual cycle
The Hypothalamic-Pituitary –Ovarian Axis
GnRHGnRH
FSHFSH LHLH
Gonadotroph cellsGonadotroph cells
ESTRADIOLESTRADIOL TESTOSTERONE
PROGESTERONEPROGESTERONE
Granulosa cells
INHIBININHIBIN
ACTIVINACTIVIN
Theca and stromal cellsTheca and stromal cells
Corpus luteumCorpus luteum
ESTRADIOLESTRADIOL
(-)(-) (+)(+) (+)(+)
(+)(+)
(-)(-)
(+)(+)
The cyclic pulsatile frequency of GnRH secretion favors FSH or LH synthesis and secretion
HORMONES OF THE OVARYHORMONES OF THE OVARY
→ → the mature ovary synthesizes and secretes estrogens, the mature ovary synthesizes and secretes estrogens, progesterone, androgen and their precursorsprogesterone, androgen and their precursors
The ovary is normally the major source ofThe ovary is normally the major source of estrogens estrogens, although the , although the conversion of androgens precursors in other tissues (eg adipose conversion of androgens precursors in other tissues (eg adipose tissue) is clinically important after the menopause and in some tissue) is clinically important after the menopause and in some women with disorders of ovarian functionwomen with disorders of ovarian function
The ovary also produces and secretes large amounts of The ovary also produces and secretes large amounts of PgPg during the during the luteal phase of the cycleluteal phase of the cycle
It is also the source of small amounts of It is also the source of small amounts of testosterone and other testosterone and other androgens : androstenedioneandrogens : androstenedione that serve not only as precursors to that serve not only as precursors to estrogen synthesis estrogen synthesis ( the theca cells, which lack aromatase, under ( the theca cells, which lack aromatase, under the influence of LH synthesize androgens; the androgens, mainly the influence of LH synthesize androgens; the androgens, mainly androstenedione diffuse into the granulosa cells ( which lack 17 androstenedione diffuse into the granulosa cells ( which lack 17 hydroxylase )and are utilized for estrogen production← under the hydroxylase )and are utilized for estrogen production← under the influence of aromatase expressed by these cells of ovarian follicle)influence of aromatase expressed by these cells of ovarian follicle) but also are released into the circulation to act on peripheral but also are released into the circulation to act on peripheral tissues; tissues;
Physiologic effects of steroid hormones►ovarian hormones-derived from cholesterol ESTROGENS: 18 C→ Estradiol (E2), Estrone (E1)- (+) the maturation of the vagina, uterus, uterine tubes at puberty as well as the secondary sex characteristics- (+) stromal development and ductal growth in the breast- are responsible for the acceleration of growth phase and the closing of the epiphyses of the long bones- alter the distribution of body fat so as to produce typical female contours, including some accumulation of body fat around the hips and breasts- role in development of the endometrial lining (proliferative phase) ( when estrogen production is properly coordinated with the production of Pg
during the normal human menstrual cycle , regular periodic bleeding occur- Cervix :(+) production of large amounts of thin watery mucus, through which sperm can penetrate most readily
PROGESTERONE: 19 C ← mainly by corpus luteum- (+) glandular development of the breasts- (+) cyclic glandular development of the endometrium (secretory phase)- ↑ the body temperature in humans - Cervix: ↓ mucus production and makes mucus thick
ANDROGENS: 21 C→ Testosterone, androstendione
ovary, conversion in adipose tissue
MENSTRUAL CYCLE
Menstrual cycle
M M
z.1 z.14 z.21
FSHE2
LH
Pg
Folicullar phase Luteal phase
Evaluation of ovarian function I.DIRECT HORMONAL ASSESSMENT : plasma levels
of FSH, LH, E2, PgAs a consequence of the changing rates of secretion of estrogens and progesterone
throughout the menstrual cycle: The basal functional status of the HPT-HPF-OVARIAN AXIS should be
explored during early follicular phase (days:2-4): FSH, LH, E2
The ovulation: during days :13-15 –the most common way is to detect the LH surge [measurement of urinary LH) (ovulation typically occurs 34-36 hours after the onset of the LH surge) [to predict that ovulation is going to occur]
Activity of corpus luteum - measurement of midluteal serum progesterone concentration (days:21-23) :
- is used to document the occurrence of ovulation ( Pg>3ng/ml –indication that ovulation has occurred)
- is used to assess a luteal phase defect ( Pg< 10 ng/ml suggests a luteal phase defect)
Evaluation of ovarian function
II. INDIRECT EVALUATION OF OVARIAN HORMONAL STATUS
A) the progestagen withdrawal test provides a useful functional assessment of estrogenous status in women with a normal outflow tract ( see later)
B) measurement of basal body temperature throughout a cycle (BBT)=the simplest test to assess progesterone secretion
Ovarian failure (OF)Ovarian failure (OF)
Classification of OFClassification of OF
-according to the site of the lesion-according to the site of the lesion– centralcentral– primary /periphericprimary /peripheric
-according to the age at onset-according to the age at onset– before pubertybefore puberty– after pubertyafter puberty
Partial ovarian failure (progesteronicPartial ovarian failure (progesteronic, , luteal phase defect)luteal phase defect) =ovulation with inadequate luteinization and=ovulation with inadequate luteinization and↓Pg secretion ↓Pg secretion during the luteal phase← result from disorders of during the luteal phase← result from disorders of gonadotropin secretion that cause poor follicular gonadotropin secretion that cause poor follicular development and ↓ granulosa-cell growth → ↓ numbers of development and ↓ granulosa-cell growth → ↓ numbers of granulosa-lutein cells and ↓Pg secretion and ↓ endometrial granulosa-lutein cells and ↓Pg secretion and ↓ endometrial maturationmaturation
Etiopathogenesis of OFEtiopathogenesis of OF
PRIMARY OF
Gonadal agenesis Gonadal dysgenesis (45 X:
Turner’sdr and its variants)
Iatrogenic (radiation, chemotherapy)
Infecions (e.g mumps)) Autoimmune Resistant ovary sdr Defects in estrogen
biosynthesis
CENTRAL OF
Hypothalamic etiology– Lesions (organic)– functional =hypothalamic amenorrhea
stress Amenorrhea associated with
eating disorders (anorexia nervosa, bulimia)
Amenorrhea associated with strenuous exercise
Pituitary etiology (see section HPT-HPF)
Clinical features in OFClinical features in OF
OF WITH OF WITH PREPUBERAL ONSETPREPUBERAL ONSET →poor sexual →poor sexual secondary sexual development and eunuchoid secondary sexual development and eunuchoid skeletal proportionsskeletal proportions– 1. SEXUAL INFANTILISM
Primary amenorrhea Absence/sparse of pubic and axillary hair Absence of breast development (telarcha) Infantile aspect of external and internal genitalia
– 2.SOMATIC MODIFICATIONS Tall stature, eunuchoid skeletal proportions (crown to pubis to
pubis to floor ratio<1) Low peak bone mass
– 3. PSYCHOLOGICAL DISTURBANCES ↓ libido
Clinical features in OFClinical features in OF
OF WITH OF WITH POSTPUBERAL ONSETPOSTPUBERAL ONSET Secondary amenorrhea infertility Decrease in axillary and pubic hair Atrophy of breast Involution of genital tract, urogenital atrophy →vaginal dryness
and pain with intercourse, atrophic cystitis Precocious appearance of wrinkles Vasomotor symptoms (hot flushes) complicatii tardive: osteoporosis, atherosclerosis, Alzheimer’s
disease
Laboratory findings in primary amenorrhea (+ absence of sexual maturation)- ovarian failure with prepuberal onset
Hormonal assessment: FSH, LH, E2 → ↓/ low-normal FSH, LH + ↓E2 = secondary (central ) ovarian failure
with prepuberal onset In these patients, LH and FSH responses to testing with GnRH may
help to differentiate delayed puberty from a more serious problem do hormonal, neuroradiologic and neuro-ophatalmologic assessment
of hypothalamus and pituitary ( e.g. tumors: craniopharyngiomas) → ↑ FSH, LH + ↓ E2 = primary ovarian failure If the patient is short in stature and has obvious stigmas of Turner’s sdr →
Barr test, Karyotype (45,X0)If the patient is of normal height or has relatively longer arms and legs
compared with the length of the trunk( eunuchoid proportions) → search for other causes of primary ovarian failure: autoimmune ( do anti ovary autoantibodies), sonography, celioscopy with biopsy ( agenesis)
Laboratory findings in secondary amenorrhea (+ normal secondary sex characteristics)- ovarian failure with postpuberal onset
→ localize the underlying cause of amenorrhea: dysfunction of either the outflow tract, the ovary, or the HPT-HPF
1.! The possibility of pregnancy should always be considered ( pregnancy test!)
2. serum PRL concentrations :→ ↑ PRL : search for a cause of hyperPRL: do TSH, FT4 ( to rule out a primary hypothyroidism), search for a prolactinoma/ “ dezinhibition” hyperPRL…
→ PRL=normal → 3. Assess endogenous estrogen (progesterone withdrawal test)The presence of endogenous estrogens can be established (by
measuring E2 levels) or attempting to induce withdrawal uterine bleeding by adm. Progesterone: an oral progesterone- eg MPA 10 mg/day or duphastone 10-20mg/day dayly for 5-10 days
test positive
Laboratory findings in secondary amenorrhea (+ normal secondary sex characteristics)- ovarian failure with postpuberal onset
Test negative = failure to induce menstrual bleeding by exogenous progestin indcates:
AA Insufficient estrogen production secondary to
–hypothalamic-pituitary dysfunction
- ovarian dysfunction
4. To differentiate them: Do gonadotropin level: FSH, LH, + E2
↓/ low-normal FSH, LH + ↓ E2 = hypotalamic-pituitry disorder
↑ FSH, LH + ↓E2 = primary ovarian failure
! A normal response ( with bleeding) following treatment with a combination of estrogen +progestin (see next) is obtained- because the outflow tract is intact
AA Defect of the outflow tract with normal estrogen production ( an infrequent cause of secondary amenorrhea)
5. If one suspects this, its integrity can be assessed by administering an oral combination of estrogen+ progesterone ( CE for 21 days adding a progestin in the last5-10 days)
- a lack of withdrawal bleeding following treatment usually indicates an abnormality of the outflow tract ( eg : Asherman’ s sdr← destruction of the endometrial cavity by chronic infections such as tuberculosis or destruction of the endometrium by curettage ; or Mullerian defects( Mayer-Rokitansky-Kuster-Hauser sdr= absence of the vagina with varying degrees of uterine development associated with normal ovarian function ( !!! Primary amenorrhea)
Treatment of OFTreatment of OF
OF with prepuberal onset – replacement therapy to allow feminization– EE2 5 g/day increasing to 10-20 g/day depending upon the clinical results or
conjugated estrogens (CE) 0.3-0.625mg/day on days 1-21 of the month; 10mg of medroxyprogesterone acetate (MPA) are then added on days 12-21 after physical signs of estrogen effect are noted and breakthrough bleeding occurs (and always within 6 months after initiating estrogen);!!! );later the patient may be switched to sequential oral contraceptives. If there is a coexisting GH deficiency (in the context of pituitary failure) first treat de GH deficiency, then add estrogen replacement therapy
OF with postpuberal onset – hormone replacement therapy (estrogens and progesterone ) in either
a (cyclical) sequential regimen (0,625 mg of CE (or the equivalent doses of a variety of available products) days:1-25 of each month + 10mg of MPA for the last 10-14 days of every month) →withdrawal bleeding or
continuous combined regimen: a combination of 0,625 mg of CE and 2,5mg of MPA is given orally every day → usually amenorrhea
GnRH or FSH+ LH stimulation treatment if fertility is desired (in seconadry(central) ovarian failure)
Partial ovarian failure (progesteronic, luteal phase defect)Partial ovarian failure (progesteronic, luteal phase defect) :progesterone products –in the last 10days :days 16-25
– Medroxyprogesterone acetate (MEDROXIPROGESTERON) 5-10 mg/zi– didrogesteron (DUPHASTON) 10-20 mg/zi– mycronizat progesterone (UTROGESTAN) 100-300 mg/zi
Turner’s sdr ( syndrome of gonadal dysgeneis)
The classical form= 45, X0 karyotype represents 50% of all patients with X Cs abnormalities
Mosaicism : 45X0/46XX, 45X0/46XX/47XXX Pathogenesis: a 45, X0 constitution may be a consequence of nondisjunction or
chromosome (Cs) loss during gamethogenesis in either parent that result in a sperm or ovum lacking a sex Cs…
Clinical presentation: the cardinal features of 45, X0 gonadal dysgenesis are a variety of somatic anomalies, sexual infantilism at puberty secondary to gonadal dysgenesia and short stature
I. Somatic anomaliesI n infancy: lymphedema of the extremities Later in life: typical facies : micrognathia, a fish-like mouth with a narrow, high- arched
palate epicantal folds, ptosis, strabism prominent, low-set, ears the neck is short, broad and the hairline in back is low; webbing of the neck the chest: usually square and shield-like, inverted nipplesAdditional anomalies: coarctation of the aorta, hypertension, renal abnormalities: rotation of
the kidney, duplication of the renal pelvis and ureter ;pigmented nevi, cubitus valgus, short fourth metacarpals and metatarsals, scoliosis, reccurent otitis media
Turner’s sdr ( syndrome of gonadal dysgeneis)
II. Short statureIs an invariable feature of the syndrome; mean final height in 45, X0 patients is
143cm (mean:133-153 cm)
← ! Is not due to a deficiency of GH, IGF-I, sex steroids, or thyroid hormone
← [it is related, at least in part, to haploinsufficiency of the PHOG (psudoautosomal homeobox osteogenic gene)/SHOX (short stature homeobox gene) in the pseudoautosomal region of the X ]
III. Gonadal dysgenesis The gonads : typically streak-like and usually contain only fibrous stromaThe genital tract and external genitalia are female in charcter but immaturePrimary amenorrhea, sexual infantilism ← impaired ovarian functionIV. Associated disorders: autommune thyroiditis, diabetes mellitus,
inflammatory bowel disease
Laboratory findings
Hormonal evaluationFSH, LH↑ + ↓E2 X-ray findings:- shortening of the fourth metacarpal - knee: deformities of the medial tibial and femoral condyles with
obliquely tipped tibial epiphyses and medial projections of the tibial metaphyses that can result in genu vallgum (Kosowicz’s sign)
-scoliosis, osteoporosis Cardiac evaluation: echocardiogram ( for cardiovascular anomalies) IVU, renal sonogram: renal abnormalities Ultrasonography of the pelvis or MRI: rudimentary ovaries/ streak gonads small
uterus
Diagnosis Barr test ( determination of the X chromatin pattern (Barr body)- negative Karyotype analysis is the definitive procedure: 45,X0 / mosaicism
Treatment of Turner’ s sdr
→ directed toward maximizing final height and inducing seconadry sexual characteristics and menarcha at an age commensurate with that of normal peers
Although the short stature is not due ←↓GH, administration of high-dose biosynthetic human GH result in an increase in final height
→ give recombinant GH → in patients who have been treated with GH and
have achieved an acceptable height, estrogen replacement therapy is usually initiated after 12-13 years of age;… after the first year : add a progestin
TESTESTESTES
Anatomy & structure-function relationship
The testes contain 2 major components which are structurally separated and serve different functions:
Leydig cells, or interstitial cells →testosterone (=the primary secretory product)
→ for embryonic differentiation along male lines of the external and internal genitalia
→ during puberty androgens mediate growth of scrotum, vas deferens, seminal vesicles, prostate, penis, (+) male secondary sexual development : skeletal growth and growth of the larynx, which results in deepening of voice, both ambisexual (pubic and axillary) hair growth and sexual (beard, mustache, chest, abdomen, and back) hair growth; (+) the epiphysial cartilaginous plates which results in the pubertal growth spurt
→ maintenance of libido and potency in the adult male
Anatomy & structure-function relationshipAnatomy & structure-function relationship
Seminiferous tubulesSeminiferous tubules ( ( =80-90% of the testicular mass) responsible =80-90% of the testicular mass) responsible for the production of spermatozoa during male reproductive life for the production of spermatozoa during male reproductive life (puberty to death)-composed of:(puberty to death)-composed of:
1. Sertoli cells-1. Sertoli cells- functions:functions:→→Line the BM and form tight junctions with other Sertoli cells (these tight Line the BM and form tight junctions with other Sertoli cells (these tight
junctions prevent the passage of proteins from the interstitial space into the junctions prevent the passage of proteins from the interstitial space into the lumenus of the seminiferous tubules, thus establishinglumenus of the seminiferous tubules, thus establishing a “a “ blood-testis blood-testis barrierbarrier””
→→SecreteSecrete ABPABP, , a molecule with a molecule with ↑ affinity for androgens; this substances, which ↑ affinity for androgens; this substances, which enters the tubular lumen, provides a ↑concentration of testosterone to the enters the tubular lumen, provides a ↑concentration of testosterone to the developing germinal cells during the process of spermatogenesis.developing germinal cells during the process of spermatogenesis.
→→FSH directly stimulates Sertoli cells to secreteFSH directly stimulates Sertoli cells to secrete inhibin inhibin and inhibin selectively and inhibin selectively (-) FSH release from the pituitary (reciprocal relationship)(-) FSH release from the pituitary (reciprocal relationship)
→→Secrete antimullerian hormoneSecrete antimullerian hormone (AMH)(AMH) → apoptosis of mullerian ducts→ apoptosis of mullerian ducts
2.Germinal cells2.Germinal cells : : SPERMATOGENESIS:spermatogonia→ I spermatocytes →II SPERMATOGENESIS:spermatogonia→ I spermatocytes →II
spermatocytes→spermatids →spermatozoa ! The interval from spermatocytes→spermatids →spermatozoa ! The interval from beginning of spermatogenesis to release of mature spermatozoa beginning of spermatogenesis to release of mature spermatozoa into the tubular lumen is 74 daysinto the tubular lumen is 74 days
AnatomyAnatomy Seminiferous tubules – 80%
– Germinal cells LEYDIG CELLS – 20%
– Testosterone
Sertoli cells-androgen-binding protein (ABP) -inhibin - AMH
Hypothalamic-pituitary-testicular axis
GnRHGnRH
FSHFSH LHLH
Pulsatile secretion
TESTOSTERONETESTOSTERONESERTOLI cells
INHIBININHIBIN
LEYDIG cellsLEYDIG cells
(-)(-) (+)(+) (+)(+)
(+)(+)
(-)(-)
Germinal cells
SPERMATOGENESISSPERMATOGENESIS
ABP
CONTROL OF TESTICULAR FUNCTIONCONTROL OF TESTICULAR FUNCTION
Hypothalamic-Pituitary-Leydig Cell ActionGnRH( HPT) secreted in pulses every 90-120min → HPT-HPF-portal blood→
gonadotroph cells→ LH, FSHLH → Leydig cells→secretion of androgensIn turn, ↑of androgens (-) LH from the anterior pituitary, through a direct
action on the HPF and an inhibitory effect at the HPT level
Hypothalamic-Pituitary –Seminiferous Tubular AxisGnRH → FSH → seminiferous tubules (Sertoli cells)→ ABP, inhibinFSH ↔ inhibinFSH is necessary for the initiation of spermatogenesis; however, full maturation
of the spermatozoa appears to require not only an FSH effect but also testosterone.
MALE HYPOGONADISM (MH)MALE HYPOGONADISM (MH)
MH CLASSIFICATION– according to the site of the lesion
Central MH primary / peripheryc MH
– according to the age at onset MH with prepuberal onset MH with postpuberal onset
Etiopathogenesis of MHEtiopathogenesis of MH
PRIMARY MH
– Bilateral anorchia (vanishing testes sdr)
– Defects in androgen biosynthesis (deficit of 17 α hydroxylase, 3β HSD deficiency)
– Defects in androgen action( complete androgen insensitivity-testicular feminization)
– Klinefelter’s sdr– iatrogenic MH: trauma,
radiation– Viral orchitis – Autoimmunity
CENTRAL MH hypothalamic-pituitary disorders)
Panhypopituitarism (tumors, infiltrations…)
isolated LH and FSH deficiency with hyposmia or anosmia (Kallmann’s sdr)
LH and FSH deficiency with complex neurologic sdr: Prader-Willi
hyperprolactinemia
Clinical presentationClinical presentation 1) androgen deficiency during the 2-3 rd months of fetal development→ varying degrees of
ambiguity of the male genitalia and male pseudohermaphroditism 2) androgen deficiency during the third trimester→ defects in testicular descent →
cryptorhidism + micropenis
3) prepubertal androgen deficiency→ poor secondary sexual development + eunuchoid skeletal proportions
– SEXUAL INFANTILISM testes remain small, the penis fail to enlarge, the scrotum does not develop the
marked rugae characteristic of puberty Absent or very sparse axillaery and pubic hair Absent or very sparse facial, chest, upper abdominal and back hair No erections Inadequate spermatogenesis
– SOMATIC CHANGES Tall stature (or normal final height) with eunuchoid skeletal proportions (upper segment(
crown to pubis) to lower segment( pubis to floor) ratio<1; similar because of the relatively greater growth in the upper extremities, the arm span of eunuchoid individuals exceeds height by 5 cm or more
Muscle mass does not develop fully, deposition of adipose tissue around the pelvic girdle
Low peak bone mass the voice remain high-pitched Pale skin, and precocious appearance of wrinkles
Psychological disturbances ↓ libidou
Clinical presentationClinical presentation
MH with postpuberal onset– Atrophy of the testes → small testes with a mushy or soft consistency– Atrophy of prostate– Erectile dysfunction, ↓ libidou– Spermatogenesis disturbances – Infertility– Absent or diminishing of facial hair (frequency of shaving ↓) and thoracic hair– ↓→0 of axillary and pubic hair– gynecomastia
– Muscle hypotrophy and excess deposition of adipose tissue around the pelvic girdle
– Pale skin+ fine wrinkles may appear in the corners of the mouth and eyes and together with the sparse beard growth → classic hypogonadal facies
– Osteoporosis, atherosclerosis, fatigue
– +/- hot flushes
Evaluation of Male Hypogonadism HORMONAL ASSESSMENT: Gonadotropin and
steroid measurement –basal determination and dynamic tests
LH, FSH- the primary use of basal FSH, LH concentrations is to distinguish between hypergonadotropic hypogonadism (primary gonadal failure) and hypogonadotropic hypogonadism (secondary gonadal failure)
→ LH, FSH –low-normal/ ↓ + ↓ T (testosterone) = hypogonadotropic hypogonadism →! Serum PRL measurement → further evaluation of anterior and posterior pituitary gland function with
appropriate pituitary function tests + neuroradiologic and neuro-ophtalmologic studies
Dynamic test : GnRH test : assess the functional integrity of the gonadotroph tissue → Do FSH, LH at 0’ and 30’ after adm. of 100ug of GnRH iv.In normal men → LH ↑ 4-5 * basal levels while FSH ↑2* basal valuesPatients with destructive lesion of the pituitary and those with long-standing
hypogonadism due to hypothalamic disorders ( secondary hypogonadism): no response/ partial response
Evaluation of Male Hypogonadism → ↑ LH, FSH + ↓ T= hypergonadotropic hypogonadism( primary
testicular disease) → chromosomal analysis → differentiate between genetic abnormalities (XXY or variants) acquired testicular defectsDynamic test: h CG stimulation testTo assess Leydig function before puberty, it is common to measure the response of
plasma T to gonadotropin stimulation as an index of Leydig cell reserve .Human chorionic gonadotropin (h CG) – biologic actions similar to those of LH ( (+) the
synthesis and secretion of testicular steroids in Leydig cells)Do T before and 72 h and 96 h after a single im dose of hCG (5000ui in adults or
100UI/kg in children)→ a normal response: a doubling of the T level→ in primary gonadal disease: 0/↓ responseUseful : for differentiation between anorchia and cryptorchidism → anorchia : no response→ cryptorchidism: T will rise
Evaluation of Male Hypogonadism SEMEN ANALYSIS TESTICULAR BIOPSY
MH treatment MH treatment = replacement treatment the aim is to restore or normalize male secondary sexual
characteristics and male sexual behavior and to promote normal male somatic development
DRUGS: TESTOSTERONE ENANTHATE or CYPIONATE im 200mg
every 2 weeks; TESTOSTERONE UNDECANOAT (NEBIDO) 1000mg every 3
months Transdermal testosterone patches: daily application TESTOSTERONE GEL (ANDROGEL) 50mg daily
! !! In hypogonadal boys : institute androgen therapy between the ages 12-14 years
! In patients with hypogonadism due to inadequate gonadotropin secretio, spermatogrnesis (and virilization) may be induced by exogenous gonadotropin injections (hCG, FSH)
Klinefelter’s syndrome (XXY seminiferous dysgenesis) =the most common development defect of the testis The underlying defect is the presence of an extrs X Cz, the usual
chromosomal karyotype being either 47XXY (classic form) or 46, XY/47, XXY (mosaic form)
Pathophysiology The XXY genotype is usually due to maternal meiotic nondisjunction
→ an egg with two X Cs ( ! The frequency of meiotic errors correlates positively with maternal age)
Histologic changes in the testes:hyalinization and fibrosis of the tubules, absence of spermatogenesis (← obliteration of the seminiferous tubules)
Leydig cells are also abnormal
Klinefelter’s syndrome
CLINICAL FEATURES - mean body height ↑←longer lower body segment; abnormal skeletal proportions
that are not truly eunuchoid ( pubis-to-floor height is greater than crown-to-pubis height but span is less than total height) ! Is not secondary to androgen deficiency but is probably related to the underlying chromosomal abnormality
-Gynecomastia -↓facial hair, axillary hair -Testes are small (<2 cm in longest axis, and 4ml in volume) and firm -Penis and scrotum ( during puberty) undergo varying degrees of development, with
some individuals appearing normal! -Infertility, ↓libidou and potency -Learning disabilities, intellectual impairement and poor impulse control - feeling of inadequacy, dyssocial behaviour- osteoporosis
Klinefelter’s syndrome
LABORATORY FINDINGS Semen analysis: Azoospermia T↓, ↑FSH (especially) ,↑LH The buccal smear is chromatin-positive (>20% of cells having a Barr
body) Chromosomal analysis → 47, XXY karyotype Testicular biopsy: hyalinization of the seminiferous tubules, severe
deficiency of spermatogonia
- TREATMENT
→ directed toward androgen replacement therapy
-