Mesothelial cell proliferation and localized pleural pseudotumour associated with Mycoplasma pneumoniae infection.

A 9-year-old boy had serological evidence of Mycoplasma pneumoniae infection. Mycoplasma organisms were cultured from throat swabs. A chest X-ray and computed tomography revealed a localized pleural tumour with pleural fluid containing mesothelial cells. It is suggested that mesothelial cell hyperplasia developed as a "reactive change" following M. pneumoniae infection.