CASE PRESENTATION: A 57 year old male presented with dyspnea and cough for 2 days. He had experienced malaise for 1-2 weeks, with fever to 101 F. His history was significant for MI, GERD and 50 pack year smoking history. On admission he had O2 saturations of 78% and chest x-ray revealing bilateral pulmonary edema. Labs showed a WBC count of 9200 cells/mm3 with an eosinophilia of 18.9%. He quickly decompensated, was intubated with repeat CXR consistent with ARDS. CTA showed hilar and mediastinal lymphadenopathy with emphysema and extensive ground-glass changes. Bronchoscopy demonstrated 24% eosinophils on BAL. No evidence of infectious etiology was found and cytology was negative. He was treated with IV steroids for a suspected acute eosinophilic pneumonia with initial improvement. Unfortunately, he decompensated due to VAP and ARF. No other etiology was found for his eosinophilia. Ultimately, a bone marrow biopsy revealed metastatic poorly differentiated neuroendocrine small cell of pulmonary origin. He continued to decline and goals of care were shifted to comfort focus. An autopsy revealed widely disseminated SCLC of the left lung with metastases to the pleura, hilar lymph nodes, right pleura, right lung, bone marrow, adrenals, left kidney, thoracic and paraaortic lymph nodes.