The ultrasound appearances are in keeping with haematometrocolpos, with a dilated uterine cavity filled with heterogeneous fluid, and a further dilated fluid-filled structure inferior to and contiguous with the uterus.
The uterus is deviated to the right, but no second uterine cavity is visible on the left. The right ovary is normal, but the left is not visualised.
Within the right flank, there are also several simple cystic structures, with no normal right kidney identified.
Conclusion:
Haematometrocolpos - gynaecology opinion recommended.
Possible Mullerian duct abnormality and multicystic dysplastic right kidney - pelvic MRI recommended to further assess.