Congenital Gynecologic defects and Mullerian anomalies

Question 1

Cardinal steps in mullerian development (devel of ducts)

Answer 1

1. Elongation
2. Fusion
3. Canalization
4. Septal resorption

*2-4 happen simultaneously

Question 2

3 types of vaginal obstruction

Answer 2

1. Imperforate Hymen
2. Transverse vaginal septum
3. Vaginal atresia

Question 3

Imperforate hymens present

Answer 3

Failure of caudel end of sino-vaginal bulbs to canalize

Question 4

How do imperforate hymens present

Answer 4

obstructive symptoms

Hymen becomes perforate (blodd accum behind hymen) or patent in the vast majority of women in fetal life

1. Cyclic pain,
2. growing abdomino-pelvic mass
3. Urinary retension

Question 5

If paramesonephric duct does not develop from top ____ develops

Answer 5

mullerian agenesis or
Unicornate uterus

(no uterus or 1 sided uterus)

failed cardinal step of elongation

Question 6

If two mullerian (paramesonephric) ducts do not fuse ____ develops

Answer 6

Uterine didelphys

• double uterus
• 2 cervix

Question 7

What do you get if septal reabsorption fails?

Answer 7

Septate uterus
- midline uterine septum

(most common uterine anomaly seen and accounts for 55% of all mullerian anomalies)

Question 8

Fibroids (leiomyoma uteri)

Answer 8

extremely common

• esp in AA
• assoc. w/ hysterectomy

Question 9

The Mullerian system (cephalad) has to develop, but it also has to unite with what?

Answer 9

Urogenital sinus (caudad) and the resulting plane of fusion must resorb.

Question 10

How do the mesonephric and para-mesonephric ducts develop?

Answer 10

In tandem.

So many of the embryologic defects of the Mullerian system, (esp the lateral fusion defects), co-evolve with the renal system.

Abnl differentiation of the mesonephric and paramesonephric ducts may also be predictive of abnl renal development.

Question 11

What arises from the mesonephric ducts?

Answer 11

Ureteral buds –>

1. Ureters
2. Renal Calyces
3. Collecting tubules

Question 12

Failure of elongation of the ducts can be Bilateral or Unilateral. What are the resulting conditions of each?

Answer 12

Bilateral elongation –>
Mullerian Agenesis
(no uterus)

Unilateral –>
Unicornuate Uterus
(1 sided uterus)

*1st step failure in cardinal mullerian development

Question 13

Failure in fusion of ducts can result in what conditions?

(ie upper Mullerian system to the caudal urogenital sinus)

Answer 13

Uterine didelphys

Transverse vaginal septum

*2nd step failure in cardinal mullerian development

Question 14

Failure of canalization can result in what condition?

Answer 14

Vaginal agenesis

*3rd step failure in cardinal mullerian development

Question 15

Failure of septal resorption results in what condition?

Answer 15

Septate uterus

*4th step failure in cardinal mullerian development

Question 16

What develops into the vagina?

Answer 16

Upper 2/3: from Mullerian system

Lower 1/3: urogenital sinus

Question 17

Transverse vaginal septum classical presentation + tx

Answer 17

young women with no menses and lower abdominal pain (hematocolpos)
*obstructive due to vaginal septal formation leading to blind vaginal pouch

Tx: skin graft if septum >2cm in order to prevent stricture of vaginal and allow for good mucosal healing.

Question 18

Most common alternate dx to consider when evaluatin pt with a transverse vaginal septum

Answer 18

Imperforate hymen.

also presents with obstructive sx even though its not a mullerian defect

Question 19

Unicornuate uterus

• what is it
• how does this affect renal development?

Answer 19

Unilateral mullerian duct elongation failure
- one duct elongates correctly and other does not
= 1 sided uterus

Renal agenesis on the same side as missing duct occurs in 40% of cases
- poor vascularity

Poor reproductive potential (spontaneous abortion 50%)

Question 20

Lateral fusion defects (during mullerian development) can be complete or partial. Complete failure of fusion results in what?

Answer 20

1. Didelpys: two uterine horns not communicating at all
   - Good reproductive outcome (unlike unicornuate uterus)

or

A longitudinal vaginal septum (not transverse that causes obstruction)

• 2 cervices
• occurs if fusion defect is lower in the vagina
• note that
  1. These defects especially lateral fusion defects co-develop with the renal system

Question 21

Which one has communicating endometrial cavities, didelphic uterus or bicornuate uterus?

Answer 21

Bicornuate
"heart shaped uterus"
- upper pt of mullerian sys fails to fuse (caudal nl)
- 1 uterus w/ 2 horns
- both horns are separated by septum

(reproductive outcomes ok ~30% compared to unicornuate uterus)

Question 22

Most common uterine anomaly seen.

- reproductive potential

Answer 22

septate uterus: failure of septal resorption btwn ducts

• very high first trimester pregnancy loss

Question 23

DES uterine malformation

Answer 23

T shaped uterus due to fetal exposure to diethylstilbestrol (DES)
- intereres with mesenchyme of reproductive tract