Diagnostic role of whole body bone scintigraphy in atypical skeletal tuberculosis resembling multiple metastases: a case report

INTRODUCTION Osseous tuberculosis can be present with unifocal or multifocal bony involvement. Although multifocal involvement of the skeletal system in areas where tuberculosis is endemic is not a rare presentation, its exact prevalence is not well known. A case of atypical skeletal tuberculosis mimicking multiple secondary metastases on radiologic and scintigraphic imaging is presented to emphasize the contribution of bone scintigraphy in the assessment of osseous tuberculosis in typical and atypical presentations. CASE PRESENTATION A 73-year-old cachectic Asian man (Iranian) presented with a general feeling of being unwell and an acute loss of vision in his left eye accompanied by a severe headache. A Tc-99 m-methylene diphosphonate bone scan demonstrated multiple regions of intense activity in the appendicular and axial skeleton, suggesting metastatic involvement. Tumor markers (PSA, CA125, CA 19-9 and AFP) were within normal ranges. Based on clinical presentation and laboratory, radiological and scintigraphic findings, a presumptive diagnosis of tuberculosis was made. Quadruple antituberculous chemotherapy was consequently started and the patient later showed marked improvement. CONCLUSION Scintigraphic bone scanning should be kept in mind when assessing bone pain in patients at a high risk of tuberculosis infection or reactivation. We present this unusual case of multifocal skeletal tuberculosis, and stress the related clinical and diagnostic points with the aim of stimulating a high index of suspicion that could facilitate early diagnosis and appropriate treatment.