CASE PRESENTATION: The patient is a 67 year old man with history of hypothyroidism and low grade B cell lymphoma initially treated with Bendamustine and Rituximab who presented with recurrence. He began treatment with Ibrutinib and developed bilateral lung infiltrates with a large nodular opacity in the right upper lobe (RUL) on re-staging CT chest. He experienced dyspnea on exertion, non-productive cough, and 30 lbs unintentional weight loss. The RUL nodule grew rapidly over a six-month period and measured 3.6 cm x 2.6 cm. It had an uptake of 11.2 SUV on PET/CT. BAL cultures grew E. coli, K. pneumonia, and MRSA. Cytology and transbronchial biopsy were negative for malignant cells. A prolonged course of antibiotics did not result in symptom resolution. A wedge resection of the RUL mass was performed. Histopathology was negative for malignancy and infection. However, areas of organizing pneumonia and fibrosis were noted. A course of oral corticosteroids resulted in symptomatic improvement and radiologic improvement in the appearance of the RUL mass.