MR findings of meniscal cysts

To characterize MR findings of meniscal cysts of the knee. We retrospectively reviewed knee MR images of surgically confirmed eighteen meniscal cysts. The location and shape of meniscal cysts were evaluated. Six of 18 cases were medial meniscal cysts and 12 of 18 cases were lateral meniscal cysts. Horizontal tears were present in all cases (100%). Four of 18 cases had rounded cysts and 14 of 18 cases had elongated cysts. In 3 of 6 medial meniscal cysts, cysts had dissected into the soft tissues distant from the meniscus, and connecting stalks were visualized. Three of 6 medial meniscal cysts were located adjacent to a meniscal tear. All of the lateral meniscal cysts occurred immediately adjacent to the meniscal tear. Meniscal cysts are associated with horizontal meniscal tear. The shapes of meniscal cysts tend to be elongated rather than rounded. Medial meniscal cysts occurred distant from or adjacent to the meniscal tear according to location of the tear. Lateral meniscal cysts occurred adjacent to the meniscal tear