Multifocal bone tuberculosis simulating metastasis
Multiple skeletal tuberculosis can be the first sign of tuberculosis. In such cases, physicians should consider tuberculosis diagnosis and take biopsies for anatomopathological evidence to make the correct diagnosis.

A 22-year-old undergraduate student suffering from a painful sternal swelling was admitted to our hospital. She has also been complaining of significant weight loss and intermittent fever in the past six months.

There was no history of Koch's or Koch's contagion. General examination of the patient did not reveal any significant abnormality except for localized tenderness over the sternum. No abnormal signs were found in the neurologic examination. Laboratory results were as follows: Routine blood test: WBC 6.1 × 109/L, HGB 94 g/L, PLT 338 × 109/L, and serum albumin level 33.2 g/L. Plasma protein electrophoresis and immunofixation electrophoresis were normal. The erythrocyte sedimentation rate (ESR) and Creactive protein (CRP) level were 73mm/hr (and 110 mg/L (normal value 0–8 mg/L), respectively. Serum tumor markers, including AFP, CEA, CA199, CA 125, and CA 15–3, were all within normal ranges. Hepatitis B surface antigen (HBsAg) and HIV were negative. Tuberculin skin test (TST) and Interferon gamma by T-SPOT were negative.

A computed tomography scan (Figure 1) revealed multiple osteolytic lesions surrounded by peri-lesional condensation of the spine, iliac wings, and left pubis with rupture of the cortical bone and bone sequestration in some places realizing a genuine mass in the sternum. There are multiple abscesses in the sternum, spine, and extension of lesions in the epidural space at L1 level. Enhanced chest computed tomography (CT) studies did not show any parenchymal lung damage or lymphadenopathy.

A body scan revealed multiple osteolytic lesions with intense FDG uptake, supporting the diagnosis of skeletal metastases.

Two fine needle aspiration biopsies of the sternal lesion showed that both bones and cartilages had a small amount of fibrous tissue attached to them.

Surgical biopsy obtained from the iliac lesion identified epithelioid cell nests, multinuclear giant cell, and cheesy necrosis, which were typical manifestations of tuberculosis. The diagnosis of multifocal skeletal tuberculosis was confirmed. After standard anti-TB drug treatment for 12 months, the patient's discomfort was remarkably relieved.