Residual pleural thickening (RPT) is the most common complication of tuberculous pleurisy (TP), despite adequate anti-tuberculous chemotherapy. At the conclusion of treatment, 43-50% of patients present RPT, with its incidence varying according to the time of evaluation. To assess the spontaneous resolution of RPT, the RPT at the completion of treatment was compared with that at the final follow-up. The factors related to the development of RPT after the completion of treatment were also studied.

The medical records of sixty four patients, diagnosed with TP between March 2001 and June 2003, were retrospectively. The RPT was measured at the completion of treatment and at the time of the final follow-up and the degree and frequency of RPT compared between the two measurements. Each time, the patients were divided into two groups: those with and without RPT. The clinical characteristics and the radiographic and pleural fluid findings of the two groups were compared.

Thirty six (56%) and 27 patients had RPT at the completion of treatment and at the time of the final follow-up, respectively (median follow up period: 8 months). Spontaneous resolution of the RPT was found in 9 patients (24%), and had decrease below 10mm in 15 (42%) during the follow-up period after treatment. The patients were initially divided into two groups: 36 and 27 patients with and without RPT, respectively. There was no predicting factor of RPT, with the exception of the presence of CRP, between the two groups. The patients were also separated into two groups at the time of final visit: 27 and 37 patients with and without RPT, respectively. The patients with RPT were found to have a lower total WBC count in pleural fluid.

57% of patients with RPT were found to have spontaneous resolution of the residual pleural thickening after completion of the chemotherapy. The time of evaluation for RPT and its predicting factors were decided after adequate follow-up, irrespective of the completion of treatment.