The etiology of meniscal cysts is controversial. Many authors advocate that trauma, chronic infection, hemorrhage, and mucoid degeneration may lead to the development of these entities9
. Because the fluid found in meniscal cysts is similar to sinovial fluid, the prevailing view is that cysts form from joint fluid that is forced through a peripherally extended meniscal tear and accumulates outside the joint capsule10
. Pain is most likely related to the associated meniscal tears, but discomfort may also be due to stretching of the knee capsule and other parameniscal soft tissues11
. The mass may be multiloculate and demonstrate thin internal septations, and its consistency may vary from soft and fluctuant to firm or bone-hard. MRI is preferred for evaluating meniscal cysts6,12
because it shows structures such as the menisci, cartilage and ligaments and is the most effective modality to evaluate soft-tissue masses. The differential diagnosis for soft-tissue masses of the knee should include sinovial cyst formation, bursal fluid collections, ganglion cysts, severe degenerative changes with osteophytic spurring and soft-tissue masses such as pigmented villonodular sinovitis, lipoma, hemangioma and sarcomas9
. Meniscal cysts tend to recur after aspiration or simple resection6
. Therefore, open or arthroscopic intra-articular surgery to treat the underlying meniscal tear is necessary for successful therapy13–15
. In conclusion, distinguishing meniscal cysts from other cystic lesions is important because meniscal cysts more often require surgery. In our case, the uncommon combination of mass size and location associated with the gender and age of the host led us to report it.