In June 2014, a 36-year-old female was admitted to the Central University Hospital of Asturias, after 72 h of diffuse abdominal pain and fever. She reported a dry cough, night sweats, diarrhea, asthenia, hyporexia, and an 8-kg weight loss accompanied by swelling and pain in both wrists, knees, and elbows that limited her mobility during the day for the past 3 months. She had no known toxic habits. The patient was diagnosed with Crohn's disease in May 2014. Since the diagnosis, she had been on proton pump inhibitors and a prednisone treatment without clinical improvement. She had no past surgical or medical history of interest. The physical examination was normal, except for the pulmonary auscultation. Crackles were found in the right upper lobe. A chest X-ray showed bilateral interstitial and alveolar infiltrates that were distributed predominantly in the right lung parenchyma with cavitations in the right upper lobe (Fig. 1A). It is important to mention that a chest X-ray was not performed in May when the patient was diagnosed with Crohn's disease, therefore we were not able to ascertain if the chest infiltrates were present before starting treatment with corticosteroids. Computed tomography of her chest showed bilateral pseudonodular infiltrates that were located predominantly in the right lung (Fig. 1B).
Her laboratory tests (complete blood count, biochemical, and basic coagulation) were within normal ranges, except for her C-reactive protein (CRP) levels, which were 14 mg/L. Bronchoscopy showed a 90% stenosis of the segmental bronchi of the right upper lobe (Fig. 2A). The bacilloscopy, PCR, and culture from the bronchoaspirate (BAS) identified M. tuberculosis. The isolate was sensitive to all tuberculostatic drugs. The patient was treated with oral rifampicin, isoniazid, ethambutol, pyrazinamide, and corticosteroids, all of which were well tolerated. Gastroenterologists re-evaluated the patient during admission and noted important granulomatous inflammation with granulomas localized in the submucosa and adipose serous tissue. Mycobacterium tuberculosis grew from a biopsy culture, and the Crohn's disease diagnosis was modified. An intestinal tuberculosis diagnosis was finally confirmed. One week after the patient was discharged, she was admitted again with a diagnosis of peritonitis because of jejunal perforation secondary to intestinal tuberculosis. A jejunal resection and anastomosis were performed without complications. The patient was discharged, and her biopsies again confirmed M. tuberculosis growth.
The patient was referred to the Rheumatology department because of migratory arthralgia in her elbows, wrists, and knee joints, particularly in the left knee joint, without definitive associated synovitis. The patient reported clinical improvement immediately after the tuberculosis treatment, which had been initiated 2 weeks previously. A clinical examination revealed monoarthritis of the left knee joint. A full blood count, liver function tests, and plasma urate levels, in addition to the erythrocyte sedimentation rate and C-reactive protein levels, were normal. The patient was negative for rheumatoid factor against cyclic citrullinated peptide antibodies (ACPA), antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies (ANCA), and antistreptolysin O antibodies (ASO). Her serum levels of angiotensin-converting enzyme and calcium were normal. The microscopy of synovial fluid aspirated from the left knee joint revealed 0.1 x 109 leukocytes/L (normal range <0.2 x 109/L) with a predominance of lymphocytes and no crystals.
The synovial biopsy revealed a mild chronic inflammatory cell infiltrate, but no histological feature characteristics of tuberculosis were present. The results from the synovial fluid, tissue cultures, and acid-fast bacilli (AFB) smears for the presence of M. tuberculosis were all negative. The patient was then diagnosed with Poncet's disease. She continued treatment with rifampicin, isoniazid, pyrazinamide, and ethambutol. Within a month of initiating this therapy, the joint pains had completely resolved. A control chest X-ray that was performed in December 2014 showed a loss of volume in the right lung. The previously observed infiltrate and cavitation in the right upper lobe had significantly improved (Fig. 2B). The patient was well at the 4-month and 6-month follow-up visits.
(B) The CT showed a loss of volume in the right lung and bilateral pseudonodular infiltrates predominantly localized in the right lung.