Hypoplastic Uterus-MRI

14 year old girl presented with primary amenorrhoea, with normal secondary sexual charectaristics and karyotyping. USG suggested Mullerian ductal developmental anomaly. MR suggest class I, American Fertility Society (AFS) classification anomaly with apparently normal but hypoplastic structures.

Teaching points by Dr MGK Murthy, Dr Sumer Sethi, Mr Hari Om, Mr Sahadev:

Two paired Mullerian ducts form predominant female reproductive system components including fallopian tubes, uterus, cervix and upper 2/3rds of the vagina. Ovaries are formed from Germ cells that migrate from primitive yolk sac to mesenchyme of the peritoneum to subsequently form Ova and supporting cells. Lower 1/3rds of the vagina is formed from sinovaginal bulb.

3 phases of Mullerian ductal developmental anomalies are possible.

a) Phase of Organogenesis in which, one or both ducts may not develop completely leading to complete agenesis / hypoplasia / unicornuate anomalies.

b)  Phase of lateral fusion where the lower segments of the Mullerian ducts fuse to form uterus, cervix and upper 2/3rds vagina. Failure of this could lead to bicornuate or Didelphys anomalies. Vertical fusion is referred to ascending sinovaginal bulb fusion to descending Mullerian system. Complete fusion leads to normal vagina, incomplete would produce imperforate hymen.

i) Septal resorption – After lower Mullerian system fuses, septum which is present gets resorbed naturally. Failure leads to septate uterus anomaly.

AFS classification suggests 7 varieties of Mullerian Ductal anomalies :

Class I – Hypoplasia / Agenesis (Mayor / Rokitansky / Hauser Syndrome refers to complete absence)

Class II – Unicornuate,      III – Didelphys,       IV – Bicornuate,       V – Septate,       VI – Arcuate

  & VII – Diethyl stilbestrol related 'T' shape uterus.