Pleural Mesothelioma, Mesothelioma Awareness

Treatment continues to be challenging and long term survival poor. Single modality treatment (surgery, radiotherapy, chemotherapy, immunotherapy and even photodynamic therapy) have not shown to improve survival 3. More recently multi-modality mesotehlioma treatment has had some impact on favourable sub groups (early disease, and epithelioid histology). Treatment includes:

   1. extrapleural pneumonectomy
   2. adjuvant chemotherapy
   3. radiotherapy

Prognosis is poor for all tumour types with an overall medial survival without treatment of 4 - 12 months 3. In favourable patient sub-groups up to 45% 5 year survival may be achievable 3, however even with aggressive multi-modality mesothelioma therapy overall 5 year survival remains poor (3 - 18%) 3 with an median survival time of approximately 18 months 4.
Differential diagnoses
The differential is dependant on the exact nature of tumour involvment and the modality. General considerations include

    * pleural effusion (espeically if loculated) : on plain film
    * benign asbestos related pleural disease
    * pleural metastases
    * peripheral bronchogenic carcinoma
    * solitary fibrous tumour of pleura
    * pleural fibrosis from infective / inflammatory source (e.g. actinomyctes, tuberculosis)
The appearance is that of soft tissue attenuation nodular mass which mesothelioma spreads along pleural surfaces including into pleural fissures and often creating a pleural rind.

Calcification is seen in 20% of cases which usually represents engulfed calcified pleural plaques rather than true tumour calcification 4. Sarcomatoid variants may demonstrate osteosarcoma or chondrosarcomatous components which may also be calcified.

An uncommon variant is the solitary mediastinal malignant mesothelioma which has appearances reminiscent of a solitary fibrous tumour of the pleura 1.

Mesotheliomas have a predilection of direct invasion of adjacent structures (chest wall, diaphragm and mediastinal content) but also frequently metastasise to contralateral lung and local nodes1-2,4.

To confidently predict chest wall invasion the extrapleural fat plane should be seen to be infiltrated and / or direct extension in bone or muscle identified 4.