Symptomatic ring-shaped lateral meniscus.

Abnormalities of the lateral meniscus in humans are a long-known fact. Three different types of discoid menisci are described in Watanabe's atlas, being considered as congenital malformations. For the second time in the literature, a fourth ring-shaped type of discoid lateral meniscus was described as an incidental finding in this Journal by Monllau et al. in 1998. The present case is the first description of a symptomatic, ring-shaped lateral meniscus with a concomitant, recurrent cyst at the lateral aspect of a child's knee.