Persistent Left Sided Pleural Effusion Due to a Large Splenic Cyst - A Cross Compartment Trigger.

Persistent left-sided pleural effusion with high output chest drainage may often be triggered by an extrathoracic etiology. We discuss the case of a 5-year-old girl presenting with dull-aching abdominal pain, progressively worsening over 10 days associated with shortness of breath. She eventually progressed to develop respiratory failure requiring mechanical ventilation. Initial investigations revealed large left-sided pleural effusion with persistent high output intercostal tube drainage. Ultrasound and computed tomography scan of the chest and abdomen identified a 5.5-cm diameter splenic cyst and also a large-sized pleural effusion (left side) with multiple septic emboli causing necrotizing pneumonia in both lungs. Investigations for probable etiologies such as pulmonary lymphohistiocytosis, lymphangioleomyomatosis, Echinococcus infection, and disseminated tuberculosis were negative. A laparotomy (diagnostic and therapeutic) was planned due to the mass effect, persisting abdominal pain, and refractory high intercostal chest drain output. Cystectomy with splenic preservation was done. Histopathological examination confirmed an epithelial splenic cyst. Intercostal drain output reduced after cystectomy and appropriate antibiotics based on microorganisms isolated. Prompt identification of an intra-abdominal source, in this case a splenic pathology, which was the trigger for persistent high output left-sided pleural fluid drainage, was an important diagnostic insight in this case.