Abstract Introduction Small-cell lung carcinoma (SCLC) is the most aggressive and the most common neuroendocrine tumor of the lung. It usually presents as a centrally-located mass or mediastinal lesion with pleural metastasis and metastatic pleural effusion (MPE) being less common. Primary pleural involvement without lung lesion is extremely rare in SCLC. We report the case of a nonsmoker male with history of asbestos exposure, found to have pleural effusion and nodular pleural thickening on imaging without any lung mass or mediastinal lymphadenopathy. Cytology of pleural fluid confirmed SCLC. Case Description A 66-year-old nonsmoker male without any medical history presents with a 3-month history of progressively worsening shortness of breath, cough, pleuritic chest pain and a 20 lbs weight loss. Patient denied any associated hemoptysis, night sweats or loss of appetite. Patient worked as a plumber with a 25 year history of asbestos exposure. He was hemodynamically stable. Examination revealed decreased air entry on left with dullness to percussion and decreased tactile fremitus without cyanosis, clubbing, edema or lymphadenopathy. Laboratory data was unremarkable. Imaging studies showed a massive left-sided pleural effusion (Figure 1a) with nodular pleural thickening without any lymphadenopathy. Findings were concerning for mesothelioma. Thoracocentesis yielded exudative lymphocyte-predominant fluid with cytology consistent with SCLC (Figure 1b). Subsequent imaging failed to show any parenchymal abnormality or evidence of distant metastasis. Patient was started on ciplastin and etoposide. He had rapid re-accumulation of pleural effusion requiring chemical pleurodesis. Discussion Significant pleural effusion requiring thoracocentesis is present in less than 3% patients with SCLC. Pleural effusion in SCLC is mostly secondary to atelectasis of the lung caused by endobronchial lesion or due to external compression of the lymphatics caused by mass. Pleural metastasis and MPE are uncommon with isolated pleural SCLC being rare and with only a few cases reported. Recognition of SCLC cells in pleural fluid with staining positive for chromogranin, synaptophysin and TTF-1 has proven extremely helpful in establishing diagnosis. Treatment approach in patients with isolated pleural SCLC should be similar to those with limited disease SCLC involving chemoptherapy and thoracic radiation. Treatment should also focus on symptom control and preventing recurrence of effusion. Conclusion This case highlights the importance of considering SCLC in the differential for isolated unexplained exudative pleural effusion, even in the absence of associated parenchymal or mediastinal abnormalities. Establishing early diagnosis will have implications on prognostication and management as isolated pleural SCLC should be treated similar to limited-stage SCLC. This abstract is funded by: None
C Ganson (Fri,) studied this question.