Imprint Cytology of Thoracoscopic Pleural Biopsy Tissue for Early Etiological Diagnosis of Pleural Effusion: A Pilot Study From India.

Thoracoscopic pleural biopsy provides the highest diagnostic yield in both malignant and tubercular pleural effusions. However histopathologic report takes 3 to 5 days to provide the diagnosis, resulting in a delay of further management plans like pleurodesis or chest tube removal. Imprint cytology of biopsy tissue can provide early information about the etiological diagnosis. Thus, we conducted this pilot study in 66 patients of exudative pleural effusions undergoing medical thoracoscopy. One or 2 biopsy pieces obtained during medical thoracoscopy from pleural nodules were used to prepare imprint cytology slides in the thoracoscopy suite. In comparison to thoracoscopic pleural biopsy, the diagnostic yield of imprint cytology of pleural tissue was 92% (49 of 53 cases) in cases of malignant pleural effusion and 75% (9 of 12 cases) in cases of tuberculosis pleural effusions. Imprint cytology provided a definite idea about the type of diagnosis, about 2.5 days before the histopathology results. By providing early etiological diagnosis, it may also decrease the duration of hospital stay and health care expenditure. A large prospective trial has been planned in our center to confirm this hypothesis.