A 30-year-old man, of East African origin, was admitted to our hospital for a constrictive chest pain. The patient's history included acute methanol intoxication with bilateral permanent blindness, due to necrosis in bilateral putamen demonstrated on magnetic resonance imaging (MRI). The patient was followed in the rheumatology outpatient clinic for AS. There was no history of smoking or illicit drug consumption but the patient admitted drinking alcohol occasionally. The patient reported low inflammatory back pain for more than one year, good response to nonsteroid anti-inflammatory drugs (NSAIDs) and computer tomography imaging (CT) of bilateral sacroiliitis (grade 2), leading to the diagnosis of AS according to the ASAS criteria (Figure 1).
The initial physical examination revealed a satisfactory general condition, no fever, normal vital signs, and synovitis of the knees. The cardiopulmonary examination was normal. Initial blood examination showed increased ESR at 80 mm/h (N < 20 mm/h) and CRP 5.8 mg/dL (N < 0.5 mg/dL), moderate hepatic cytolysis (<2X Normal values), and anicteric cholestasis. Total bilirubin, hematological tests, and renal function were normal. Troponin level was initially increased to 0.091 mg/dL; it decreased after 3 hours to 0.023 mg/dL. Chest radiography revealed no abnormalities. An electrocardiogram revealed widespread concave S-T elevation and a P-R depression (D2 D3). Cardiac echography was normal. Myocardial infarction was ruled out, and the patient was treated with NSAIDs with good clinical response.
Because of the persistence of increased inflammatory markers and negative biological infectious investigations and first imaging studies (chest X-Ray and abdominal ultrasound), a whole-body positron emission tomography combined with a computed tomography (PET/CT) using F18-fluorodeoxyglucose as radiotracer (18F-FDG) was performed to detect any occult infectious or inflammatory sites. The 18F-FDG-PET/CT revealed mediastinal, hilar pulmonary, supraclavicular and cervical bilateral hypermetabolic lymph nodes, hypermetabolic condensation in the right lung, multiple hypermetabolic lesions of axial skeleton (Figure 2(a)), in particular the thoracic spine, rib cage, and bilateral sacroiliac joints (Figure 3). This was suggestive of either DT or lymphoma. A tuberculin skin test was done and was highly positive (22 x 27 mm), whereas analysis for TB was negative in the sputum and urine. Bronchoscopy with biopsy of the right pulmonary lesion was performed. Histological analysis of the lesions showed the presence of necrotic granuloma, and microbiological examination revealed mycobacterium tuberculosis. The diagnosis of DT with axial skeleton, lung, and lymph node involvement was retained, and the patient was treated with Isoniazid 300 mg/d, Rifampicin 300 mg bid, Pyrazinamide 500 mg/d, and Ethambutol 400 mg qid. 18FDG-PET/CT was repeated after 1 year of treatment and showed total disappearance of the aforementioned lesions (Figure 2(b)).