Answer: Staphylococcus aureus Pulmonary infection due to Staphylococcus aureus can occur among individuals with Staphylococcus aureus colonization of the skin or nares, either in the community or in the hospital setting. Staphylococcus aureus pneumonia can also occur following viral pneumonia [2, 3] or in the setting of right-sided endocarditis with septic emboli. Community-acquired Staphylococcus aureus pneumonia frequently affects immunocompetent hosts without significant prior exposure to the health care system. Pneumonia in these patients is frequently preceded by extra-pulmonary staphylococcal infection, particularly skin infection. This patient had no prodrome of viral pneumonia, and right-sided endocarditis was not supported by blood cultures or transthoracic echocardiogram. Therefore, the source of infection is theorized to be the bee-sting and subsequent soft tissue infection he had sustained the week before presentation, which may have caused a transient Staphylococcus aureus baceteremia. The patient subsequently received right decortication, right tube thoracostomy, and right upper lobe wedge excision for treatment of a pulmonary abscess and bilateral empyema. The pathology of the excised tissue demonstrated Methicillin-resistant Staphylococcus aureus (MRSA). The patient improved after the procedures, and he was discharged on an extended course of outpatient intravenous Vancomycin therapy. A. Wegener's granulomatosis is a systemic vasculitis that almost always involves the upper and lower respiratory tract. Pulmonary nodules and infiltrates are frequent manifestations in the lung, and cavitation may accompany these findings. C. Radiographically, Klebsiella pneumonia starts with lung consolidation and bulging interlobar fissures, followed by the development of multiple small cavities. Alcoholism and smoking are important risk factors for community-acquired Klebsiella pneumonia. However, a growing proportion of patients are immunocompromised and acquire this infection in the hospital. In this patient, the history of acute onset and rapid progression, lack of typical systemic symptoms, and absence of dynamic features on the chest radiograph make Klebsiella pneumonia unlikely. D. Acute Blastomycosis presents with a sudden onset of fever and cough, accompanied by alveolar infiltrates on chest radiography. Occasionally, nodular densities may also be detected on chest radiography. Cavitation is an uncommon finding in acute disease. . E. Pulmonary tuberculosis generally presents subacutely with weeks to months of fever, night sweats, weight loss, and productive cough, with a late finding of hemoptysis. The chest radiograph typically reveals pulmonary infiltrates, often associated with cavitation, in the apical lobes. Acknowledgements We thank Dr. Anurag Duggal and Dr. Rajiv Sahni, Division of Infectious Diseases, Akron General Medical Center, for reviewing the case. References 1. Gadkowski LB, Stout JE. Cavitary Pulmonary Disease. Clin Microbiol Rev. 2008; 21: 305–333. 2. Gillet Y, Issartel B, Vanhems P, et al. Association between Staphylococcus aureus strains carrying gene for Panton-Valentine leukocidin and highly lethal necrotising pneumonia in young immunocompetent patients. Lancet. 2002; 359:753-759. 3. Morens DM, Taubenberger JK, Fauci AS. Predominant role of bacterial pneumonia as a cause of death in pandemic influenza: implications for pandemic influenza preparedness. J Infect Dis. 2008; 198:962-970. Biographies: Yuanjie Mao is a second year resident in Internal Medicine at Cleveland Clinic Akron General Medical Center, OH. Rupesh Raina is an attending physician in Nephrology at Cleveland Clinic Akron General Medical Center, OH. Figure Legends Figure 1 Left: Chest X ray showed bilateral pleural effusion, status post left tube thoracostomy. Middle and right: chest computed tomography indicated right apical cavity, right loculated plural effusion, and left plural effusion status post left tube thoracostomy.