Diagnosing Mesothelioma from Pleural Fluid: The Cell Block Technique

Turkish researchers say a method for concentrating cancer cells from the lung fluid of mesothelioma and lung cancer patients into a single “block” for examination may result in a more accurate diagnosis than traditional fluid analysis.

Pleural effusion or excess lung fluid is often one of the first signs of mesothelioma. Patients may experience this fluid collection as chest pressure, pain, or inability to take a full breath. Suspected mesothelioma patients with pleural effusion will often undergo thoracentesis, a technique for removing some of the fluid for examination.

In the current study, researchers compared the traditional method of analyzing cancer cells in pleural fluid with a method that involves concentrating those scattered cells into a “block” that can be cut through and examined like a solid tissue sample. Ten milliliters of pleural fluid were taken from each of 194 patients suspected of having mesothelioma or another type of cancer. The samples were then divided into two parts – one for examining in the conventional way and the other for examining with the cell block method.

Cells evaluated using the conventional examination method were classified as either benign, malignant or undetermined. Using this method, 154 samples were reported as benign, 33 as malignant and 7 as suspicious for malignancy.

When the cell block method was used to evaluate cells collected from the pleural fluid, the results were much more specific. With the cell block technique, 147 samples were reported as benign, 12 as metastatic, 4 as squamous cell carcinoma (a form of skin cancer), 26 as different types of lung cancers, 3 as lymphoma, and 2 as mesothelioma.

Writing in the Asian Pacific Journal of Cancer Prevention, the authors conclude that the cell block diagnostic method “increases the diagnostic yield” from pleural effusions that accompany cancers like mesothelioma. Mesothelioma is an extremely rare cancer and one of the most difficult to diagnose. Along with symptoms like coughing, shortness of breath, chest pain and fatigue, a history of asbestos exposure is usually a key reason to suspect mesothelioma.

Source:

Ugurluoglu, C et al, “Importance of the cell block technique in diagnosing patients with non-small cell carcinoma accompanied by pleural effusion”, 2015, Asian Pacific Journal of Cancer Prevention, pp. 3057-3060.