Herein, we report a rare case of primary lung lymphoma in a 61 year-old woman with a history of 6-month nonspecific symptoms like dry cough, fever, chills and weight loss. She was admitted to a hospital and received broad-spectrum antibiotics but discharged without full recovery. In her second hospital admission, a bronchoscopic evaluation and transbronchial biopsy were performed, which were not diagnostic. Finally, an open lung biopsy was done. Immunohistochemical (IHC) staining of the specimen suggested pulmonary Hodgkin lymphoma. Because of disease recurrence, a second bronchoscopy was performed and endobronchial biopsy revealed transformation to anaplastic lymphoma. In the second recurrence, we decided to reevaluate the last biopsy specimens in greater details. Finally, after conduction of several staining patterns, the diagnosis of primary composite lymphoma of the lung was made.