Résumé
@# OIiier disease is a rare nonhereditary disorder characterized by multiple enchondromas in which malignant changes may occur. We report the case of a 15-year-old male with Ollier disease who presented with a large mass in the left upper arm for several months. Radiography revealed hugelytic mass in the proximal half to two-thrids of the left humerus. Bone scan showed irregularly increased tracer uptake in the head to mid shaft of the left humerus that is suggestive of malignant disease. Pathology analysis demonstrated proximal humeral chondrosarcoma, grade 1. In Ollier disease, bone scan may be used for monitoring the lessions with suspicion for malignant transpormation.
Sujets)
Chondrosarcome , EnchondromatoseRésumé
Bone scan is a sensitive imaging procedure for cancer patients who are at high risk for bone metastases. Despite the high sensitivity, Tc-99m methylene diphosphonate (MDP) is not a specific tracer and its increased uptake may also be seen in extra-osseous areas. In cases where localization of extra-osseous sites of MDP uptake on planar imaging prove to be difficult, single photon emission computed tomography with computed tomography (SPECT/CT) may be useful. A known lung cancer patient was referred for whole body bone scan to detect bone metastasis. Planar images showed tracer accumulation in the left area of the head, suspicious for skull metastasis. SPECT-CT imaging of the head was done for further evaluation, which showed Tc-99m MDP uptake in the left temporoparietal lobe. Magnetic resonance imaging (MRI) of the brain was subsequently done, which showed a subacute brain infarct corresponding to the Tc-99m MDP-avid focus. Thus, SPECT-CT was helpful in proper anatomical localization of the focal Tc-99m MDP uptake in the head, which otherwise might have been easily mistaken for skull metastasis should only planar imaging was used.