11th January 2024

A 71-year-old lady with known small cell lung carcinoma is admitted for elective drainage of a known malignant pleural effusion.

A 71-year-old lady with known small cell lung carcinoma is admitted for elective drainage of a known malignant pleural effusion. She undergoes the procedure on the ward, and over the course of 48 hours, 2.5L of fluid is drained without apparent complication. The drain continues to swing appropriately, but she remains symptomatic with shortness of breath and pain on deep inspiration. A repeat chest x-ray is completed, which shows resolution of the effusion; however, a 2cm rim of air is noted. 

Given the underlying aetiology and management, what is the most likely explanation of these findings?

Select the SINGLE most appropriate option from the list below. Select ONE option only.