RESUMO

Florid reactive periostitis is a benign and rare lesion that is a recurrent diagnostic problem. Its etiopathogenesis remains unknown. Florid reactive periostitis consists of a fibrotic, cartilage-producing tumor accompanied by an aggressive inflammatory periosteal and soft tissue reaction. It typically occurs in adolescents and young adults, mostly female; it often affects hand and foot bones, and it may occur in long bones. Its diagnosis remains a major challenge due to the vast possibility of differential diagnoses. Therefore, careful clinical, radiological, and pathological evaluation is required to establish a proper diagnosis. We report the case of a patient with florid reactive periostitis in the proximal phalanx of the right index finger, who underwent surgical excision with a wide margin, from the second ray to the proximal third of the second metacarpal bone, and evolved without complications, with satisfactory range of motion and strength.