An 88-year-old man presented with a 2-week history of gradually progressive breathlessness and dry cough. There was no associated fever, loss of weight, or appetite. He denied any edema of the feet and orthopnea.
His history was remarkable for hypertension and coronary artery bypass grafting done 8 years ago. He was diagnosed with GIST 4 months ago when he presented with gastric discomfort and a computed tomography (CT) scan of the abdomen showed a 12 cm x 11 cm x 8.5 cm posterior mediastinal mass. A subsequent endoscopic ultrasound-guided biopsy showed tumor cells positive for C-Kit and DOG-1. He was commenced on tablet imatinib 400 mg/day for his GIST, but after 1 month of the treatment, he began to complain of breathlessness on exertion. He was a lifelong nonsmoker. There was no history of tuberculosis or tuberculosis contact.
On examination, he was mildly tachycardic with a pulse rate of 90/min. His blood pressure was normal and jugular venous pressure was not raised. He had no pallor, icterus, cyanosis, clubbing, lymphadenopathy, or pedal edema. His respiratory system examination revealed diminished breath sounds in the right infrascapular and infraaxillary area. His abdomen was soft on palpation and no organomegaly was felt.
His complete blood count, renal function tests, and liver function tests were all normal. His transthoracic two-dimensional echocardiogram showed normal left ventricular (LV) ejection fraction of 55%. A chest radiograph [Figure 1] showed a right pleural effusion and high-resolution CT chest [Figure 2] showed a large right-sided pleural effusion and unchanged posterior mediastinal mass with no consolidation or lymphadenopathy.
He underwent a thoracentesis of the pleural fluid; 1100 ml was aspirated. Results of pleural fluid aspiration were: protein: 3.3 g/dl (total serum protein: 5.4 g/dl); lactate dehydrogenase (LDH): 223 IU/L (serum LDH: 280 IU/L); white blood cell count: 1040/mm3 (50% lymphocytic); adenosine deaminase (ADA): 4.1 (normal: 0-40 U/L). His pleural fluid cytology showed lymphocyte predominance and no malignant cells. Pleural fluid aerobic and tuberculosis cultures and GeneXpert were all negative. He was diagnosed to have an exudative effusion with a low ADA. An oncologist's opinion was sought who ruled out metastasis as a cause of the effusion.
In the absence of other causes of pleural effusion, a diagnosis of imatinib-induced pleural effusion was made. Imatinib was withdrawn; the patient gradually improved and a repeat chest X-ray at 3 months poststoppage of drug showed complete resolution and no refilling of the fluid [Figure 3]. The patient declined any further treatment for his GIST and was not put on any other medication. He remains under regular chest radiograph and sonography follow-up over 1 year and has no recurrence of his effusion.