The External Genitalia

Question 1

Category

Answer 1

1. Micropenis, Hypospadias and Absent palpable gonad

2. Clitoromegaly, fusion of labia

Question 2

Steps in examination for external genitalia

Answer 2

1. Description of external genitalia
   • Phallus - size and urethral opening site
   • Labioscrotal fold - Pigmentation, rugae?
   • Goand- ? palpable (look for it from external inguinal ring to scrotum
   • Presence of sexual hair
   • Presence of inguinal hernia
2. Description of anus - its anatomical relationship with genitalia
3. Note the growth parameters of child: ? tall, ? obese
4. Note the general status of child:
   • Hyperpigmentation/ pallor
   • Virilization signs: Acne, Hirsutism and musculization
   • Dysmorphic face
5. Abdominal examination and PR examination after with permission for uterus and ovary
6. Look for breast development (can be gynaecomastia)
7. CNS examination: Visual change/ field defect
8. BP
9. Others:
   • Hand for Polydactyly
   • Cardiac murmur
   • Mentality

Question 3

Causes of Ambiguous external genitalia

Answer 3

1. Male Pseudohermaphrodite
   • Congenital Adrenal Hyperplasia - 3β -Hydroylase and 21-hydroxylase deficency
   • PARTIAL testicular feminization syndrome: 5-hydroxylase deficency

• Testicular failure of any causes
• • Hypopituitarism - Midline defect, Kallman syndrome and pituitary failure
• • Syndromes: Klinefelter’s, Prader willi, Lawrence Moon

2. Female Pseudohermaphrodite
   • Congenital Adrenal Hyperplasia - 21 / 11β / 3β -Hydroylase deficiency
   • Virilizing tumours
   • Maternal Androgen intake (presence in newborn)
3. True Hermaphrodite - presence of ovotestis

N.B.Causes of hypogonadism in Male - as above

Question 4

Gonad development in Fetus

Answer 4

• In fetus, Y chromosome provides the HY antigen that stimulates the fetal gonad to develop into testes: The Sertoli cell secretes Mullerian Inhibitory Factor and Leydig cells secretes Testoseterone.

Question 5

5 alpha reductase deficiency:

Answer 5

5 alpha reductase deficiency: No Testosterone is converted into dihydroxytestosterone which is for virilization and musculinization:
• • Clinical features: Ambiguous similar to male with micropenis, hypospadias, undesended testes and bifid scrotum
• • Patients has normal pubertal change except scanty sex hair/ beard, no acne (As the development of internal male sexual organs depend on testosterone only)

Question 6

Testicular Feminization:

Answer 6

Due to testosterone receptor protein defect, no testosterone effect whatsoever and child with normal female external genitalia. Genetically the child is XY and has MIF that inhibits the Mullerian duct

Question 7

Micropenis

Answer 7

• Definition:

Question 8

Principles in management of Ambiguous external genitalia

Answer 8

1. Determination of one’s genetic sex and functional sex
2. Watch out for salt losing crisis
3. Counselling of parental condition, avoid name and sex first
4. Genetic counselling - can be a AR situation

Question 9

Precocious puberty

Answer 9

Definition:
• Girl - 8 years old (Breast - sex hair - height - mense
• Boy - 9.5 years old (Testis - sex hair - penile growth - height)

Causes:
• True precocious puberty

1. Intracranial pathology
• Brain tumor
• Post encephalitis
• Post meningitis
• Cerebral malformation
• Hydrocephalus
• Spinal bifida

2. Syndromes
   • Neurofibromatosis
   • TS
   • McCune Albright Syndrome
3. Idiopathic
4. Hypothyroidism

• Pseudo-precocious puberty
1. Adrenal
• Adrogen/ oestrogen secreting tumor
• CAH in boys

2. Gonadal
   • Leydig cell tumor in testis in boys
   • Thecoma or teratoma in ovaries in girls
3. Exogenous drugs
4. Ectopic HCG secretion - Choriocarcinoma, Hepatoblastoma

Question 10

Steps in examination of Precocious Puberty

Answer 10

1. Examine the external genitalia and assess the secondary sexual characteristics: Stages of development.
   Significant changes if:
   • Boy : 25ml - macro testes

In girls -
• Note androgen effect- deep voice, hirsutism, clitoromegaly, and acne
• Note oestrogen effect - muscosal redness and secretion of labia and vagina, size of uterus on PR exam

• True precocious puberty has pubertal events in normal sequence.

3. General examination
   • Assess mentality
   • Height measurement
   • Look for signs suggesting hypothyroidism or neurocutaneous syndrome
4. Abdomen for any masses including PR for pelvic mass - e.g. ovarian cyst
5. Test visual acuity and field
6. Measure BP

Question 11

Management of precocious puberty

Answer 11

1. Deal with primary pathology

2. Idiopathic cases: 
• Counselling and explanation
• if Sx distress pt: Upet one's life and pt at risk of final shortness then consider drug - 
• • Progesterone
• •  Cryproterone (Anti-androgen)
• •  LHRH analogue eg Buserelin

• S/Es of Progesterone - GI upset, Wt gain, breast development, acne and jaundice
• S/Es of Cryptoterone - Wt gain, gynaecomastia, galactorrhoea, sedation and depression