This case illustrates the presentation of primary pulmonary large B-cell lymphoma as large cavitating lesions.
Although the gross cavitating lesions were initially thought to be infectious in nature (the first bronchoscopy isolated Klebsiella), the patient did not have any septic symptoms at that time and was relatively well for the degree of lung involvement.
Bronchoscopy was then repeated and confirmed lymphoma. The PET showed that the disease was confined to the chest.
This large cavitating lesion is an atypical presentation for lung lymphoma. Cavitations are known to arise from pure necrosis in the majority of cases but have also been attributed to having a component from concurrent bacterial colonization in the necrotic center of tumors 2.
The patient has started chemotherapy with a good response within a few months (followup CT not shown).