Mechanism?

Failure of paranephric ducts to completely fuse
(Bicornate uterus - note dipped-in outer contour)
What caused this?

Upper UTI with a urea-spliting bacteria, i.e. Staph, Proteus, Pseudomonas, Klebsiella, Mycoplasma
(This is a staghorn calculus, aka struvite calculus, a complication of upper UTIs)
Dx?

Arcuate uterus
(Notice fundus is enlarged but otherwise structurally normal)
Pathogenesis?

Failure of medial walls of caudal portion of Mullerian ducts to resorb
(Septate uterus - notice normal outer contour distinguishes this dx from bicornate uterus)
Treatment?

Usually none if asymptomatic, which most are
(Multiple, white, whorled masses in ovary = leiomyoma)