Hemithorax

A hemithorax is one side, either left or right, of the chest cavity. Each hemithorax contains a lung, its pleural lining, and the space between them, and is separated from the other side by the mediastinum (the central compartment holding the heart, esophagus, and great vessels). In medical reports, doctors describe findings as being in the "right hemithorax" or "left hemithorax" to specify which side is affected.

Origin

From the Greek hemi- meaning "half" and thorax meaning "chest" or "breastplate." The term has been used in anatomical and clinical writing since the 19th century to designate one side of the divided chest cavity.

Significance in Asbestos Context

For patients with pleural mesothelioma or asbestos-related pleural disease, the hemithorax is the anatomical "unit" doctors use to describe where disease is located and how extensive it is. Most pleural mesotheliomas begin in and remain confined to one hemithorax for much of their course, which is why imaging reports, surgical plans (such as pleurectomy/decortication or extrapleural pneumonectomy), and radiation fields are all described in terms of the involved hemithorax. Terms patients will see in their records ("right hemithorax opacification," "volume loss of the left hemithorax," "trapped lung in the affected hemithorax") all describe how the tumor or pleural fluid is changing one side of the chest. Tracking whether disease crosses to the opposite hemithorax, the diaphragm, or the mediastinum is a key part of staging and prognosis.

Example Sentence

The CT report stated that there was a large pleural effusion and nodular thickening throughout the right hemithorax, with no involvement of the left side.

Related Terms

Pleura, Pleural Effusion, Mediastinum, Pleural Mesothelioma, Extrapleural Pneumonectomy, Pleurectomy/Decortication

Notes

• When reading imaging reports, note which hemithorax is involved and whether subsequent scans show new findings on the opposite side. Bilateral involvement changes staging and treatment options.
• Ask your thoracic surgeon or oncologist whether disease is confined to one hemithorax, as this directly affects eligibility for surgical procedures like pleurectomy/decortication.
• Keep copies of all CT, PET, and MRI reports; the descriptions of hemithorax volume, fluid, and pleural thickening over time are important evidence of disease progression for both medical care and legal claims.