A Rare Case of Third Metatarsal Pseudoepiphyses in a Pediatric Patient.

We report the case of a 10-year-old boy presenting for evaluation of bilateral arch pain and flatfoot deformity. Foot radiographs revealed a mushroom-shaped cleft traversing the proximal end of the third metatarsals, consistent with a pseudoepiphysis. There is literature suggesting that this is a common finding in the distal first metatarsal as well as pediatric metacarpal bones; however, the incidence in the third metatarsals has not been clearly established. Only one study to date has analyzed accessory proximal growth centers in the second metatarsal, and it reported this anomaly in 6.3% of pediatric radiographs reviewed. To our knowledge, there are no reports in the literature on complete bilateral pseudoepiphyses in the third metatarsals. Recognizing this anomaly is important to prevent misdiagnosing as a malignant or traumatic pathology.