Pedal Intraosseous Epidermoid Inclusion Cysts, a Case Report and Literature Review.

Abstract: Intraosseous epidermoid inclusion cysts (IO-EIC) rarely affect the foot and may be difficult to diagnose in the setting of concomitant infection. We present the first recorded case involving a metatarsal and an “inside out” mode of tissue violation, along with a review of the literature. A search of the PubMed, Embase and Google Scholar databases was undertaken. Only complete or near complete cases were reviewed. Twelve other cases of pedal IO-EIC were found. The majority of cases involved a phalanx of the hallux, were in the older age group and all had a delay in diagnosis necessitating the need for amputation in some. In the setting of infection, antibiotics were only effective when coupled with operative intervention. Careful clinical examination is critical for timely diagnosis of IO-EIC of the foot. Antibiotics for an infected or ruptured cyst are ineffective in isolation. Early surgical excision is recommended as any delay results in significant tissue loss and amputation.