INTRODUCTION: Empyema necessitatis occurs when infected pleural fluid dissects spontaneously into the chest wall resulting from bronchopleural extension of a peripheral lung infection or inadequate treatment of an empyema, after a necrotizing pneumonia/abscess. Infections with Streptococcus milleri, anaerobes, Staphylococcus aureus and Actinomyces are associated with this presentation. We discuss a case of tuberculous empyema necessitatis presenting to a cancer center with bone lesions and a back mass.
CASE PRESENTATION: This 70 year old woman had a phalloides tumor of the breast nine years ago. She presented with thoracic spine and right rib cage pain without cough, fever, sweats, chills or weight loss. Dyspnea of unclear etiology had been present for several months and she had been placed on oxygen. Spine MRI showed a lytic lesion at T7 with a paraspinal mass without cord compression. Needle aspirate showed purulent material with negative cultures/cytology and open resection was planned. Prior to surgery, rapid growth of a right subscapular mass was noted, with no new symptoms. PMH: Tuberculosis (TB) as a child in Russia, treated with pneumothorax; asthma and atrial fibrillation. No history of smoking. PE: Normal except a right 12 × 8cm subscapular mass on the right posterior hemithorax, soft to palpation without skin inflammatory changes. LAB: PFTs showed severe mixed obstructive/restrictive ventilatory defects. Blood work was normal except for an elevated bicarbonate. Chest CT scan (Figure 1) revealed right hemithorax volume loss, borderline mediastinal nodes, large pleural based mass with dense calcifications, adjacent component of loculated fluid measuring 11.3 × 4.0cm, bone destruction at the level of T7 with a paraspinal mass measuring 4.3 × 2.5cm, continuous with low density necrotic mass in the chest wall 12.0 × 5.11cm. Approximately 500cc of pus was aspirated from the subcutaneous mass. Stains were negative and broad spectrum antibiotics were started. Clinical Diagnosis: Tuberculous Empyema Necessitatis with Osteomyelitis and Paraspinal Space Abscess. Clinical Course: Surgery was performed with evacuation of the abscess cavity, resection of posterior portions of the 7th and 8th ribs with creation of an Eloesser flap. Granulomatous inflammation of the subcutaneous tissue (Figure 2) with osteomyelitis of the ribs and acid fast bacilli (AFB) on Fite stain were seen; cultures grew Mycobacterium Tuberculosis. Antituberculous regimen was started and drainage from the pleural cavity continues. There is on going destruction of the T 7 vertebrae with movement of fluid toward T 7 neural foramina but no spinal cord involvement: neurosurgical evaluation ongoing.
DISCUSSIONS: TB is the most common cause of pleural effusions worldwide (30–60%) and accounts for 2 to 5% of all pleural effusions in the United States. Tuberculous empyema is rare and often asymptomatic, until fluid drains outside the pleural space. A hallmark of TB empyema necessitatis is a chest wall mass without inflammatory signs or systemic symptoms as in our patient. Findings of purulent pleural fluid with organisms on AFB stain, WBC > 100,000/ul; neutrophil predominant, low pH and glucose and an elevated protein and LDH are usually seen. Extension of fluid to paraspinal and epidural space can occur from empyema or osteomyelitis.
CONCLUSION: Empyema necessitatis is rare but can be due to TB. Chest CT findings are often diagnostic, although fistula may not be seen. Chest wall findings and chest CT in our patient with past TB were virtually diagnostic. Open drainage is needed in addition to chemotherapy.
DISCLOSURE: Shilpa DeSouza, No Financial Disclosure Information; No Product/Research Disclosure Information