Pseudo-tumor mimicking indwelling pleural catheter tract metastasis in mesothelioma.

Patients with malignant mesothelioma are known to be at risk of developing needle tract metastasis from seeding of malignant cells at the pleural intervention site. Histologic confirmation of needle tract metastases is seldom sought. The diagnosis and management (often radiotherapy) are almost always based on clinical judgment of new subcutaneous lesions at prior pleural puncture sites in mesothelioma patients. We report 2 patients with mesothelioma who developed new subcutaneous nodules at their indwelling pleural catheter insertion site, mimicking tract metastases. Biopsies of both lesions revealed benign etiologies and both resolved without requiring irradiation. These cases remind clinicians that new subcutaneous lesions can be benign even when arising at pleural puncture sites of malignant pleural mesothelioma patients. Percutaneous biopsy can clarify the diagnosis in suitable cases.

A pleural effusion of multiple causes.

Multiple medical disorders can lead to the development of pleural effusions. Most effusions are given a single diagnosis in clinical practice. However, the cause of the effusion can change during the disease course, and concomitant yet distinct causes are often underrecognized. We highlight this point by reporting a complex case of recurrent pleural effusions with different predominant causes during the disease course. Five causes for the pleural effusion were diagnosed, namely malignant pleural effusion, empyema, chylothorax, transudative pleural effusion secondary to hypoalbuminemia, and esophagopleural fistula. This case serves as a reminder to clinicians that recurrent pleural effusion, even within the same pleural space, can arise from different causes and, whenever clinically appropriate, reinvestigation of the pleural effusion may be needed.