Florid reactive periostitis of the metacarpal and phalanx: 2 case reports.

Florid reactive periostitis is a rare benign fibro-osseous proliferative lesion of soft tissue and is mainly composed of fibrous connective tissue and mature bone. The lesion usually occurs in the finger and seldom in the metacarpal. The lesion mimics malignant and infectious disorders, thus often leading to inappropriate treatment. Radiography usually shows an ossified mass attached to the underlying hand bones without interruption of the cortex. We report 1 case of florid reactive periostitis with unossified mass and underlying bone marrow edema in the metacarpal of hand and 1 case with adjacent cortical destruction in the phalanx. In addition, we describe the imaging findings of computed tomography CT and magnetic resonance imaging MRI and discuss their diagnostic values compared with routine radiographic examination.