A 62-year-old male patient with history of chronic lymphocytic leukemia presented with cough, shortness of breath, cervical lymphadenopathy and sweating for the last 3 months. A cervical excisional biopsy showed undifferentiated carcinoma and infiltration with small lymphocytes consistent with chronic lymphocytic leukemia. A PET/CT which was ordered for staging and detection of primary tumor revealed hypermetabolic mass at the right hilar region. Also, metastatic bilateral cervical, supraclavicular, bilateral axillary, abdominal, pelvic lymphadenopathies in addition to multiple liver and widespread bone marrow metastasis were detected (Fig. 5). Although complete blood count was normal, diffuse bone marrow involvement prompted us to attempt a bone marrow biopsy. Biopsy showed poorly differentiated large cell carcinoma of the lung.