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Findings reveal a T1 & T2 hyperintense lesion with Rokitansky's nodule noted within the lesion.

Final Diagnosis: Mature Cystic Teratoma

Discussion

Mature teratomas are congenital neoplasms that arise from more than one of the three germ cell layers (endoderm, mesoderm, and ectoderm). The typical imaging appearance of a mature cystic teratoma is a cystic mass with a distinct capsule containing sebaceous fluid that is most often unilocular (88%) but can be multilocular. Mature teratomas characteristically contain components of fat (93%), calcifications (56%) such as teeth or bone, and often floating masses of hair or soft tissue. 
The Rokitansky nodule is the most common finding of a mature teratoma & are described as hyperechoic protrusions arising from the inner surface of a cyst, often containing hair, calcifications (teeth or bone), and fat. 

Reference & Further reading