Abstract Pleural effusion is the accumulation of fluid in the pleural space, and can be caused by pulmonary, pleural, or extrapulmonary etiologies. Effusions may present unilaterally or bilaterally, with bilateral effusions often being transudative secondary to systemic processes such as heart failure, cirrhosis, or nephrotic syndrome. Malignant pleural effusions typically present as exudative, unilateral effusions; however, up to 10-13% may present bilaterally. This case highlights the importance of maintaining suspicion for malignancy in the setting of bilateral pleural effusions. A 66-year-old female presented with progressive dyspnea over several weeks. Initial chest x-ray revealed complete opacification of the left hemithorax. Chest CT showed a massive left pleural effusion with left lung collapse, mild mediastinal shift, and a small right pleural effusion. Diagnostic and therapeutic left-sided thoracentesis removed 1.8 L of serosanguinous fluid, showing an exudative effusion with pH 7.18, suspicious for parapneumonic effusion given left lower lobe pneumonia and scattered right-sided infiltrates. Bilateral pleural effusions, ascites, and a micronodular liver contour raised suspicion for hepatic hydrothorax or decompensated heart failure. The patient was initiated on antibiotics and diuretics with clinical improvement, and discharged without complication. Less than three weeks later, she returned with recurrent dyspnea and was found to have bilateral pleural effusions with compressive atelectasis of both lower lobes on chest CT. Review of prior cytology from the initial thoracentesis identified malignant cells consistent with metastatic carcinoma. Patient underwent a right-sided thoracentesis, yielding removal of 1.4 L, which confirmed exudative effusion with elevated LDH. Immunostaining suggested adenocarcinoma favoring a primary gynecologic source, likely ovarian or uterine in origin. The patient had recurrent pleural effusions with multiple hospitalizations for dyspnea and therapeutic thoracenteses. Chemotherapy was initiated but poorly tolerated, thus the patient ultimately elected hospice care. Malignant pleural effusions are typically unilateral and occur in advanced malignancy with poor prognosis. Bilateral malignant pleural effusions are uncommon, often misattributed to transudative processes like heart failure or cirrhosis, potentially delaying recognition of malignancy. This case highlights the diagnostic challenge of coexisting liver disease obscuring underlying malignancy. Clinicians must maintain high suspicion for malignancy, especially with exudative, serosanguinous pleural fluid and concerning cytology. Early recognition and prompt diagnosis allow for timely oncologic referral and prevent delays in appropriate care. This case illustrates the critical role of cytologic evaluation in bilateral pleural effusions and reinforces the importance of early diagnosis to guide management, intervention, and palliative care. This abstract is funded by: None
Bharwani et al. (Fri,) studied this question.