A 30-year-old female patient presented to the surgery outpatient clinic of our institution with complaints of non-radiating epigastric pain accompanied by mildly painful epigastric swelling which had been gradually progressing for the past 4 months. There was a history of undocumented/unconfirmed episodes of pyrexia. There was no history of trauma, significant weight loss, chronic medical illness or family history of tuberculosis. On examination, a mildly fluctuant and tender midline epigastric swelling, 3x2.5 cm in size, was seen in the epigastric region. Overlying skin was unremarkable. Axillary examination was normal. The patient was sent for an abdominal ultrasound as a suspected case of an incompletely treated liver abscess.
Ultrasound of the abdomen using curvilinear transducer (3-5 MHz) revealed no evidence of hepatomegaly or liver abscess or any other abdominal pathology. Examination of the epigastric region using a high-frequency transducer (7-9 MHz) revealed subcutaneous tissue thickening with an irregular hypoechoic collection measuring 9x9.8x10 mm in the lower plane. The hypoechoic collection showed linear echogenic bone fragments located on its posterior aspect (Figure 1). Osteomyelitis of the xiphisternum likely to be of tubercular etiology was considered at this stage. Simultaneously, blood samples were obtained and laboratory examination showed marginally raised total leucocyte count (13600/cumm) with lymphocytosis (42%) and raised erythrocyte sedimentation rate (85 mm at the end of the first hour using Wintrobe's method) and C-reactive protein levels. Patient was HIV-negative. Mantoux test was positive (20x20 mm) after 72 hours.
Subsequently, Lateral chest radiographs focused at the distal sternum were obtained, demonstrating lytic destruction of the xiphisternum (Figure 2). Contrast enhanced Multidetector computed tomography (MDCT) of the thorax and abdomen was obtained to exclude mediastinal/abdominal extension of the disease. CT examination of the thorax revealed almost complete erosion of the xiphoid process of the sternum. The surrounding soft tissue revealed poorly-enhancing inflammatory changes in the form of stranding (Figure 3). The lung window view showed patchy fibrotic nodules in both lungs. Additionally, traction brochiolectasis was observed in the right upper lobe and left lower lobe suggesting an old infective etiology (Figure 4). There was no other focus of tubercular infection in the chest and abdomen on CT scan. Contrast-enhanced MRI demonstrated abscess formation in the soft tissue of the xiphisternal region (Figure 5A, 5B). MRI also helped to exclude concurrent spinal tuberculosis.
Sonography-guided antigravity aspiration was carried out on two occasions which revealed scant blood mixed aspirate. The samples were subjected to microbiological and pathological analyses. Microscopic findings were suggestive of non-specific inflammation. The aspirate did not show pyogenic organisms on gram's staining or acid-fast bacilli on Ziehl-Neelsen staining. ADA levels were 367 IU/L in the tissue aspirate. Culture for pyogenic organisms was negative after 48 hours of incubation. Polymerase Chain Reaction (PCR) for Mycobacterium tuberculosis and Amplified Mycobacterium tuberculosis DNA test (AMT-DT) were also performed and were positive for tuberculosis. The sputum examination was negative for acid-fast bacilli. Enzyme-linked immunosorbant assay (ELISA) was negative for HIV I & II antibodies. The patient's immune status was normal with no other focus of infection either clinically or radiologically.
Standard multidrug antitubercular chemotherapy (Isoniazide 5 mg/kg; Rifampicin 10 mg/kg; Pyrazinamide 25 mg/kg; Ethambutol 15 mg/kg; along with pyridoxine 20 mg) was administered to the patient. The constitutional symptoms and pain subsided over the next 12 weeks and the size of swelling gradually decreased over 6 months. The drug therapy was continued for a period of 12 months. The patient was asymptomatic when last seen in the outpatient department, which was 18 months post therapy. The patient was informed that data concerning her case would be submitted for publication, and therefore a written, informed consent was obtained.
CT thorax: coronal reformatted lung window view, shows traction bronchiolectasis along the horizontal fissure in the right lung and posterior basal segment of the left lung (white arrows) with multiple fibrotic nodules in bilateral lung parenchyma.