Pleural Tumors

Localized Fibrous Tumors of Pleura

• • Previously called "localized mesotheliomas"

  • Arise from subpleural fibroblasts

  • Cause pulmonary nodules to pleural masses

  • Involvement of visceral pleura more common than parietal

  • Benign (70%) patterns

  • -Fibrous

    -Cellular

    -Mixed

  • Malignant (30%) patterns

  • -Tubulopapillary

    -Fibrous

    -Dimorphic

  • Behave as sarcomas

Diffuse Malignant Pleural Mesothelioma

• • Most common primary tumor of pleura

  • 4 histologic variants

  • -Epithelial or rubopapillary (35-40%): Associated with pleural effusions, better prognosis

    -Fibrosarcomatous/mesenchymal (20%) "dry" mesotheliomas

    -Mixed (35-40%)

    -Undifferentiated (5-10%)

Epidemiology

Diffuse Malignant Pleural Mesothelioma

• • Strong link to asbestos exposure: 300 × increased risk

  • Amphibole fibers (crocidolite, amosite, etc) and soil silicate zeolite lodge in terminal airways migrate to pleura

  • Latency after asbestos exposure: 15-50 years

  • Right hemithorax (60%) affected more than left (35%), bilateral (5%)

Symptoms and Signs

Localized Fibrous Tumors of Pleura

• • Most asymptomatic

  • Large tumors may produce symptoms of bronchial compression

  • -Dyspnea

    -Cough

    -Chest heaviness

  • Rarely, hypoglycemia from production of insulin-like peptide (4%)

  • Clubbing, hypertrophic pulmonary osteoarthropathy (20-35%)

Diffuse Malignant Pleural Mesothelioma

• • Dyspnea on exertion common

  • Chest wall discomfort common

  • Cough, fever, malaise, weight loss, dysphagia

  • Advanced disease:

  • -Pain

    -Abdominal distention

    -Pericardial tamponade

    -Superior vena cava (SVC) syndrome

Imaging Findings

Localized Fibrous Tumors of Pleura

• • Chest film: Well circumscribed mass, may move with changes in position

  • Pleural effusion in 15%

Diffuse Malignant Pleural Mesothelioma

• • Chest film: Pleural thickening, effusion (75%), narrowing of intercostals spaces

  • CT scan: Diffuse irregular pleural thickening

Localized Fibrous Tumors of Pleura

• • Fine-needle aspiration (FNA) may be suggestive

  • Surgical excision often necessary for diagnosis

Diffuse Malignant Pleural Mesothelioma

• • FNA usually inadequate

  • Biopsy via small incision or video-assisted thoracoscopic surgery (VATS)

  • Immunohistochemistry stains for carcinoembryonic antigen (CEA), LeuM1, B72.3, BerEP4, negative; vimentin and keratin stains positive

  • Calretinin stain (specific for mesothelial cells) usually positive

• • Chest x-ray

  • Chest CT scan

  • Fluorodeoxyglucose positron emission tomography(FDG-PET) scan sometimes useful

Localized Fibrous Tumors of Pleura

• • Complete resection; lobectomy usually not required, wedge resection recommended if visceral pleural involved

  • If arises from parietal pleura, chest wall resection necessary

  • After excision, no further therapy needed

Diffuse Malignant Pleural Mesothelioma

• • Radiation and chemotherapy alone have no impact on survival

  • Surgery: 2 approaches

  • 1. Radical pleuropneumonectomy

    2. Parietal pleurectomy with decortication: Better outcome and lower morbidity when combined with radiation therapy

  • Chemotherapy, photodynamic therapy, immunotherapy, gene ...