Background Primary pleural or secondary malignancy is a common cause of pleural effusion. The incidence is about 200000 cases per year. Pleural biopsy remains gold standard investigation of choice. Those with negative biopsies are either discharged or have follow up depending on the multidisciplinary team decision.

Objective To review the outcome of all patients with negative pleural biopsy including any follow up imaging for up to two years.

Methods Retrospective analysis of 162 consecutive patients who underwent video-assisted thoracoscopic surgery (VATS) (100) and local anaesthetic thoracoscopy (62) between January 2011 and December 2012 across two large UK tertiary referral centres. Patients referred from peripheral centres were excluded.

Results Of the 162 patients, male:female ratio was 109/53; average age was 69. Pleural biopsy histology was malignant in 63% (100); mesothelioma 43%, lung cancer 35%, extra pulmonary 22%. Granulomatous inflammation 6% (9). Benign 31% (53); chronic inflammation 28, fibrosis/thickening 8, reactive 13 and others 4. See Table 1.

Of the 53 benign, 11 (21%) developed malignancy before 2 years. 6 (55%) required repeat biopsy. Patients alive at the end of 2 years – 1 Malignant and 26 benign of the 53.

Imaging performed during 2 years follow up at 6, 12, and 24 months: plain chest radiograph 22 (42%), 12 (23%), 13 (25%) and CT scan was done at 5 (9%), 8 (16%), 2 (4%) respectively.

Conclusion Our data suggests that 21% of patients were diagnosed as malignant within 2 years of initial negative biopsy, which is higher than expected.¹ There is a need for early follow up and imaging in patients with negative pleural biopsy. Further studies are required to establish the follow up interval and imaging modality.

Reference

1. Janssen J, Ramlal S, Mravunac M. The long-term follow up of exudative pleural effusion after nondiagnostic thoracoscopy. J Bronchol 2004;11(3):169–174.