Pyothorax-associated lymphoma diagnosed by preoperative pleural effusion aspiration cytology: a case report

Pyothorax-associated lymphoma (PAL) is a comparatively rare tumor, and it is difficult to definitively diagnose it preoperatively, especially in patients with only pleural thickening without mass formation. Pleural effusion aspiration cytology is a useful and easy diagnostic method for a large number of chest diseases. However, the cytologic findings of PAL have been rarely described. Here we report on the cytologic findings in a patient with PAL, manifested by pleural thickening without mass formation, and which was diagnosed preoperatively by pleural effusion aspiration cytology.

A 64-year-old man was admitted to our hospital because of pleural thickening involving an empyema sac located in the left thorax and rapidly increasing pleural effusion. He had a 30-year history of chronic empyema and a 10-year history of diabetes mellitus. Left pleural effusion aspiration cytology showed malignant lymphoma. The patient was admitted to our hospital for PAL treatment. Because of poor respiratory function, he only underwent decortication with complete resection of the thickening pleural peel. However, he was well, without recurrence, 5 years after the operation. The histologic examination revealed that lymphoma cells were located only in the thickening pleural peel.

This is a very rare case of PAL diagnosed by preoperative aspiration cytology for an increasing pleural effusion. This report demonstrates that pleural effusion aspiration cytology can be valuable for the diagnosis of PAL.