INTRODUCTION: Empyema necessitatis (EN) occurs when an empyema extends through the parietal pleura into the surrounding tissues. EN has become less common with the routine drainage of empyema and antibiotic use. Most cases reported in the modern literature have been in immunocompromised patients.
CASE PRESENTATION: A homeless 59-year-old African-American man with chronic hepatitis C and hypertension presents with a finger abscess. During the interview, he mentions a left sided chest mass that has been present and slowly enlarging for several months. He reports a cough productive of yellowish sputum and weight loss of about thirty pounds over the past three months. He has no history of tobacco, alcohol, drug abuse, HIV or immunodeficiency. Upon exam, the patient has a soft, nontender, nonulcerated mass located on the anterior left chest wall measuring 14 cm in diameter. Blood counts and metabolic panels are within normal limits. HIV testing is negative. A chest radiograph and CT scan are performed. The Chest CT demonstrates a large mass communicating with the pleural space. The lung parenchyema has some nodular areas and areas of cavitation. Sputum sample reveal acid fast bacilli (AFB) and PCR confirms mycobacterium tuberculosis.
DISCUSSIONS: EN is a rare complication of pulmonary infection. EN is usually located on the anterior chest wall between the second and sixth intercostal spaces. However, this complication has been reported to occur in the bronchi, esophagus, breasts, diaphragm, retroperitoneum, and groin. The most common causative agent is mycobacterium tuberculosis with actinomyces being the next most likely. Cases have been described with streptococcus pneumoniae, staphylococcus aureus, gram negative bacilli, polymicrobial infections, blastomycosis, and neoplasia. Chest imaging usually shows a calcified well defined encapsulated pleural mass associated with an extra pleural mass. Our case highlights the connection between the pleural and extra-pleural collections, which is rarely seen due to the small size of the connection. Treatment consists of antimicrobials and drainage of the abscess. Before antibiotics, mortality was as high as 87% among those with tuberculosis as the causative agent.Our patient was started on antibiotic therapy with ethambutol, isoniazid, pyrazinamide, and rifampin. The chest wall abscess was drained by cardiothoracic surgery. Material from the abscess was AFB positive. Antibiotics were continued at a local tuberculosis hotel under direct supervision with follow-up by the health department and the infectious disease team.
CONCLUSION: Empyema necessitatis is a rare complication most often associated with tuberculosis infection. EN should be included in the differential when evaluating a chest wall mass, especially in a patient with constitutional symptoms, risk factors for tuberculosis infection or immune compromise.
DISCLOSURE: Scott Kellie, No Financial Disclosure Information; No Product/Research Disclosure Information