Malignant mesothelioma

1) Extensive nodular or lobular thickening of the pleura which may conglomerate to form a circumferential lobular sheet of  soft tissue density encasing the lung
  - Often runs into fissures accompanied with varying amounts of pleural fluid
   * neoplastic encasement of lung fixes the mediastinum ,so  mediastinal shift away from the site of effusion is not seen in MM
 2) Ipsilateral volume loss
 3) On CT- soft tissue density of tumor tissue is easily distinguished from adjacent pleural effusion ; but when nodules are tiny the only CT feature may be pleural effusion
 4) Calcification -rare