A 63-year-old male farmer of Chinese Han ethnicity presented pain in his left neck, right chest wall and back for 10 months, along with swelling under the right nipple for 1 month. He was admitted to the hospital on November 26, 2014. The left neck pain with no particular predisposing factors was dull and intermittent in the beginning. It gradually progressed and extended to the left upper extremity, where the pain was more serious and accompanied by numbness at night. The pain eventually spread to the chest and back. The patient has no history of exposure to TB or any recent weight loss, cough, low-grade fever, decreased appetite or night sweats.
During the previous 10 months, the patient had been hospitalized first in the department of orthopedics and then in the department of interventional radiology. Enhanced chest computed tomography (CT) studies did not show any parenchymal lung lesions or lympho-adenopathy. Then, CT and magnetic resonance imaging (MRI) both showed multiple osteolytic bone lesions at C4, C5, C6, T10 and T11 vertebrae, which were noted along with similar lesions on the ribs of these vertebrae. The dural sac was pressed at the corresponding surface. A bone marrow biopsy revealed granulocytosis in the bone marrow. A fine needle aspiration biopsy of the 9th rib lesion showed that both bones and cartilages had a small amount of fibrous tissue attached to them. Accordingly, multiple bone metastases were suspected (Fig. 1). Final confirmation of the diagnosis was not performed, and the patient was discharged from the hospital with a prescription of morphine sustained-release tablets to relieve the pain. The diagnosis of the patient could not be confirmed by several hospitals for the following 8 months and no additional biopsies were performed. 
The patient was re-admitted on November 26, 2014 as the conditions worsened with the development of numbness in both legs. A red swollen area appeared on the right side of the chest without obvious predisposing factors 1 month before re-admission. The swelling with obscure boundary and poor mobility grew gradually from the initial size to about 1 cm x 1 cm at the time of re-admission.
The vital signs of the patient were stable at the time of re-admission. No obvious abnormal signs were observed in neurologic examination. Laboratory results were as follows: Routine blood test: WBC 11.7 x 109/L, N 75.8 %, RBC 3.06 x 1012/L, HGB 89 g/L, PLT 232 x 109/L, and serum albumin 38 g/L. Serum protein electrophoresis and immune fixation electrophoresis were normal. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level were 60.08 mm/hr (normal value 0-15 mm/hr) and 37.55 mg/L (normal value 0-8 mg/L), respectively. Serum tumor markers including AFP, CEA, CA199, CA724 and PSA, were all within normal ranges. Interferon gamma by T-SPOT was negative. Hepatitis B surface antigen (HBsAg) and HIV were negative.
A smear test for acid-fast bacilli of pleural effusion was negative on November 27, 2014 (CT didn't show pleural effusion in April, 2014). A routine pleural effusion test showed: yellow, turbid, WBC: 1500/mul (neutrophils 55 %, lymphocytes 45 %), and RBC: 1550/mul. Rivalta's test was positive. Pleural effusion biochemical examination showed: total protein 48.3 g/L, lactate dehydrogenase 188 U/L, adenosine deaminase 12.7 U/L, and glucose 7.08 mmol/L. Malignant cells were not detected in the pleural effusion. 18 F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/computed tomography (CT) revealed that there were multiple metastases in the bilateral pleural effusion, whole bone, bilateral hilar lymph nodes, mediastinal lymph node and chest wall (Fig. 2). But a primary tumor location was not detected. 
On December 2, 2014, the swelling soft tissue under the right nipple ulcerated. Both a smear test of acid-fast bacilli and a polymerase chain reaction (PCR) of TB-DNA of the pus were positive. As a result, the diagnosis was corrected to multiple musculoskeletal tuberculosis. After 1 month of anti-tuberculosis combination therapy (rifampicin, isoniazid, pyrazinamide and ethambutol), the swelling significantly decreased and the back pain was reduced. After 3 months of treatment, the numbness in the arms resolved.