Intramedullary osteosclerosis of the tibia with inflammatory features: Multimodality imaging findings.

Intramedullary osteosclerosis (Ribbing disease) is a rare benign sclerosing bone disorder characterized by diaphyseal cortical thickening and endosteal sclerosis, most commonly involving the tibia. We report the case of a 30-year-old woman presenting with a one-year history of progressive bilateral tibial pain, initially affecting the right side. Radiography and computed tomography demonstrated asymmetric diaphyseal cortical thickening with medullary canal narrowing and metaphyseal sparing. Magnetic resonance imaging revealed marked cortical thickening associated with bone marrow edema and circumferential periosteal reaction, with post-contrast enhancement of the medullary cavity and periosteum. Bone scintigraphy showed increased metabolic activity in both tibial diaphyses. Laboratory findings were unremarkable, and infectious and neoplastic etiologies were excluded. Due to persistent symptoms despite prolonged conservative management, surgical cortical fenestration was performed, resulting in partial clinical improvement. This case highlights an atypical imaging presentation of intramedullary osteosclerosis, demonstrating that inflammatory features such as bone marrow edema and periosteal reaction may be present in symptomatic cases. Recognition of this spectrum is essential to avoid misdiagnosis and to differentiate this entity from infectious and neoplastic processes.