Disorders of gonads Flashcards
What is the typically presentation of male hypogonadism?
Usually symptoms of androgen deficiency:
Poor libido Erectile dysfunction Loss of secondary sexual hair Small soft testes Gynaecomastia
Name 3 congenital causes of primary gonadal disease in males
Anorchia (absence of both testes)
Leydig cell agenesis
Cryptorchidism (testicular maldescent)
Chromosome abnormalities e.g. Klinefelter syndrome
Enzyme defects: 5 alpha-reductase deficiency
(5a-reductase converts testosterone into the more potent dihydrotestosterone)
Name 3 acquired causes of primary gonadal disease in males
Testicular torsion Orchidectomy Local testicular disease Chemotherapy/radiation toxicity Orchitis e.g. mumps CKD Cirrhosis/alcohol Sickle cell disease
Explain how CKD causes hypogonadism
Renal failure is associated with decreased luteinizing hormone (LH) production, and decreased prolactin (PRL) clearance.
Hyperprolactinaemia inhibits GnRH release from the hypothalamus.
Uraemia inhibits LH receptors.
Name 2 causes of secondary gonadal failure in males
Hypopituitarism e.g. tumours, iatrogenic Normosmic idiopathic hypogonadotropic hypogonadism Kallmann syndrome Severe systemic illness Severe underweight
(Hyperprolactinaemia)
What investigations should be measured in
male hypogonadism?
Basal testosterone, LH, FSH
Semen analysis, chromosomal analysis, bone-age estimation
Pituitary MRI, prolactin, pituitary function test
Describe the management of male hypogonadism
Underlying cause is rarely reversible. Testosterone replacement therapy to control symptoms and prevent long-term osteoporosis.
Gonadotrophin deficiency: LH and FSH replacement, or pulsatile GnRH if fertility required.
How is cryptorchidism (undescended testes) managed?
Surgical exploration and early orchidopexy in early childhood.
HCG trial may induce descent.
After puberty: Orchidectomy advised
What is Klinefelter syndrome?
A common congenital abnormality (1:1000 males) featuring an extra X chromosome (47,XXY)
How does Klinefelter syndrome present?
Patients usually present in adolescence with poor sexual development, small or undescended testes, gynaecomastia, or infertility.
Long leg length, tall stature due to lack of epiphyseal fusion in puberty.
Signs of androgen deficiency including small, pea-sized but firm testes and gynaecomastia.
Occasional behavioural problems and learning difficulties.
What is the treatment for Klinefelter syndrome?
Androgen replacement therapy unless testosterone levels are normal.
No treatment possible for infertility and abnormal seminiferous tubules.
What is Kallmann syndrome?
Isolated GnRH deficiency characterised by delayed/absent puberty and impaired sense of smell.
Define erectile dysfunction and briefly describe its aetiology
Erectile dysfunction is the inability to achieve or maintain erection. May be associated with lack of libido, both are common symptoms of male hypogonadism.
ED may be psychological, neurogenic (most common with DM), vascular (PVD), endocrine, or related to drugs.
What is the treatment of erectile dysfunction?
Stop any offending drugs
Sildenafil* aka Viagra (Phosphodiesterase inhibitor)
Also consider injections and implants
Psychosexual counselling if psychological cause
Define gynaecomastia and state 3 causes
Development of breast tissue in males
Can be physiological Hyperthyroidism Hyperprolactinaemia Renal and liver disease Hypogonadism Oestrogen-producing tumours (testis, adrenal) HCG-producing tumours (testis, lung) Drugs: Spironolactone*, oestrogen, digoxin
Describe the consequences of oestrogen deficiency
Amenorrhoea Small atrophic breast Thinning and loss of pubic hair Atrophic vulva and vagina Dry vagina and dyspareunia Small atrophic uterus Osteoporosis
Define amenorrhoea and differentiate between primary and secondary amenorrhoea
Amenorrhoea is the absence or cessation of menses.
Primary: Failure to establish menstruation by 16 in girls with normal secondary sexual characteristics, or by 14 in girls with no secondary sexual characteristics.
Secondary: Absence of menstruation for 3 months in a woman who previously had cycles.
State 5 causes of primary amenorrhoea
Physiological: Pregnancy, constitutional delay in puberty
Pathological with normal secondary sexual characteristics: GU malformations e.g. imperforate hymen, transverse septum, absent vagina or uterus
Pathological with no secondary sexual characteristics: Ovarian failure and hypothalamic amenorrhoea
Outline the causes of ovarian failure
Ovarian dysgenesis e.g. Turner syndrome (45,X)
Premature ovarian failure
Steroid biosynthetic defect e.g. 21 hydroxylase or 5 alpha reductase deficiency
Resistant ovary syndrome
What are the causes of hypothalamic amenorrhoea
Weight loss Excessive exercise Anorexia Stress Depression Chronic systemic illness
State 5 causes of secondary amenorrhoea
Physiological: Pregnancy, lactation, menopause
Iatrogenic: Progesterone contraception, radiotherapy
Uterine: Cervical stenosis, Asherman’s syndrome (endometrial fibrosis)
Ovarian: Premature ovarian failure, chemotherapy
Hypothalamic: Weight loss, anorexia, stress etc.
Pituitary: Prolactinoma, hypopituitarism, Sheehan’s, sarcoidosis
Thyroid disease
Endocrine: PCOS, Cushing’s, Addison’s, Acromegaly
Androgen-secreting tumours of ovary or adrenal
When should amenorrhoea be referred to endocrinology?
Any of the following:
Hyperprolactinaemia
Low FSH and LH
Increased testosterone not explained by PCOS
Features of Cushing’s syndrome
Features of last-onset congenital adrenal hyperplasia
Name 3 causes of hyperprolactinaemia
Prolactinoma Idiopathetic hyperprolactinaemia Hypothyroidism (TRH stimulates PRL) PCOS Lactation Oestrogen Dopamine antagonists e.g. Risperidone
How is hyperprolactinaemia treated?
Dopamine agonists e.g. Cabergoline
What is Turner syndrome and how does it present?
Genetic disorder affecting 1:2,000 girls, characterised by a partly or completely absent X chromosome (45,X).
Short stature, webbing of neck (40%), high-arched palate, low-set ears.
Features gonadal dysgenesis with streak ovaries. Increased incidence of autoimmune disease, biscuspid aortic valve, coarctation, aortic dissection, horseshoe kidneys etc.
What is polycystic ovary syndrome?
Multiple small cysts within the ovary, and excess androgen production. It affects 1 in 5 women, and is the commonest cause of hirsutism.
Associated with T2DM (10x), HTN, hyperlipidaemia, and increased CV risk (2-3x).
Describe the clinical features of PCOS
Most present with amenorrhoea/oligomenorrhoea and/or hirsutism and acne, shortly after menarche.
Many are overweight or obese.
How is PCOS investigated?
Serum total testosterone
Ovarian USS
What is the commonest drug cause of gynaecomastia?
Spironolactone
