Radionuclide Bone Scintigraphy: An Interesting Case Report

It is well established that Technetiummethylene diphosphonate (Tc MDP) whole body bone scintigraphy (WBBS) can demonstrate multiple lesions with increased radiotracer concentration in involved bone. But it is hard to differentiate multiple benign osteolytic lesions from disseminated bone metastases. Even combined with medical history and multiple imaging results, clinical diagnosis of metastatic lesion remains a challenge. This can affect the treatment procedure. Here the role of skeletal scintigraphy in a case of eosinophilic granuloma is evaluated and concluded that additional attention should be given before diagnosing any case as bone metastases. INTRODUCTION Eosinophilic granuloma (EG) of bones is the commonest benign manifestation of HistiocytosisX malady (1). There is a certain predilection to males (2:1) (2). Usually it is asymptomatic but may appear as a palpable, tender mass over the affected area. Tc MDP WBBS is commonly used to detect metastases from malignant tumor as it is more sensitive than X-rays and allow the whole body to be surveyed (3). In bone scintigraphy eosinophilic granuloma, multiple myeloma, disseminated tuberculosis, enchondroma and several other diseases show multiple photopenic lesions that is similar with the findings of malignant bone metastases. Therefore, prior to delivering the report of metastases, benign osteolytic lesions should be considered according to other imaging findings, detailed medical history, or even the preliminary pathology result. A case is reported here where the patient developed EG involving multiple bones.