Case presentation
A 53-year-old man with a history of diabetes and hypertension, was followed since 2020 for a severe spontaneous pain on the left leg without triggering factor, mild at first, then getting worse gradually. Pain was prolonged, chronic and recurrent and was worsened by physical activity. He did not report any illness of the right leg. Nonsteroidal anti-inflammatory drugs (NSAID) were ineffective. The patient did not report any notable trauma or infection or familial bone disease history.
At examination, we did not notice local heat, swelling, or redness. Laboratory data were within normal limits: erythrocyte sedimentation rate (ESR) :20 mm, C-reactive protein (CRP) :5 mg/l, normal liver and kidney function, calcemia : 2.3 mmol/l, phosphoremia : 1.18 mmo/l, alkaline phosphatase: 58 UI/L.
Plain Radiographies showed bilateral massive sclerotic intramedullary lesion of tibial shafts, cortical bone thickening, and narrowing of the medullary cavity. No periosteal reaction or soft-tissue abnormality or fracture lines were seen (Figure 1, Figure 2). The diagnosis of IMOS of both tibia shafts was suspected. As etiological diagnosis of the osteosclerosis, we discussed malignant tumors (osteosarcoma, lymphoma, bone metastasis), benign tumors such as multifocal osteoid osteoma, stress fractures, metabolic disorders and hereditary bone diseases. Nevertheless, all these diagnosis were excluded as laboratory findings were normal, no familial bone disease history was present, no extensive periosteal new bone formation and soft-tissue abnormality were noted on the radiography. Indeed, the bilateral characteristics of the process, and the exclusion of other diagnosis were sufficient to retain the diagnosis of IMOS and we did not perform any supplementary exploration. Concerning therapeutic management, the patient received level 2 analgesic and NSAID with a good response. The last outpatient meeting was held on February 2022 and he reported a good evolution.