Approximately 95% of pleural masses (tumors) are of metastatic origin. Primary pleural tumors are rare, and their frequency is 0.3%-3.5%. 90% of primary pleural tumors are mesothelioma, 5% are solitary fibrous tumors, and 5% are others.
Benign Pleural Lesions
- Pleural Plaques
- Extrapleural Fat
- Localized Solitary Fibrous Tumor
Malignant Pleural Lesions
- Malignant Mesothelioma
Pleural plaques can cause diffuse or local pleural thickening. They can have smooth or irregular surfaces. These plaques are associated with infections such as tuberculosis, pleural pathologies such as hemothorax or empyema, and asbestos exposure and drugs.
The most common cause of bilateral pleural thickening is asbestos exposure. These calcified plaques are usually benign lesions that do not need surgery and are followed up. If malignancy is suspected, VATS Biopsy is performed.
The thickening of the fatty tissue in the extrapleural space is most common in the posterior, mainly between the 4th and 8th ribs. They are silent and do not require surgery.
Lipomas are often asymptomatic. Since lipomas contain homogeneous fat densities, they can be easily diagnosed with CT. Malignant liposarcoma is suspected in heterogeneous masses. MRI can show the fat content in heterogeneous masses.
Localized Solitary Fibrous Tumor
80% of these tumors originate from the visceral pleura, and 20% from the parietal pleura, mediastinum, or diaphragm. They may reach dimensions that fill the hemithorax. Tumors from the visceral pleura are connected to the lung by a pedicle. Although solitary fibrous tumors are benign features, 12% of these tumors are malignant. The indicators of malignancy are infiltration into the surrounding tissue and tumors extending into the lung tissue.
Diagnosis of Pleural Masses
PA chest X-ray
- Tumor may not be clear on chest X-ray.
- On thorax CT, they appear as well-circumscribed, non-invasive lesions.
- Although the role of PET-CT in the evaluation of these tumors is unknown, moderate FDG uptake is common in case reports.
- Biopsy with invasive methods for histopathological examination is a must.
- Tru-cut biopsy
- Thoracoscopic (VATS) biopsy
Solitary fibrous tumor diagnosis is made by immunohistochemical examination of the surgically removed specimen.
Pleural Masses Treatment
Treatment of solitary fibrous tumors is complete surgical removal.
At least 2 cm of normal tissue from the tumor margin is the recommended resection according to the guidelines.
If it is attached to the thoracic wall, we perform extrapleural dissection.
Segmental resection or lobectomy of tumors may also be considered in some cases.
The long-term recurrence rate in benign tumors is 8%, and we perform resection in case of recurrence. Long-term survival in benign tumors is excellent.
Recurrence is common in malignant tumors.
Adjuvant therapy is not recommended in stage 0-2 patients. Adjuvant therapy is for stage 3 patients, and radiological follow-up should be performed every six months for two years.
90% of primary pleural tumors are mesothelioma. Malignant mesothelioma is discussed in another section.
Many cancers in the body can metastasize to the pleura. The most common metastasis to pleura is caused by lung cancer, breast cancer, gastrointestinal system, kidney, and ovarian tumors.
Treatment of pleural metastases varies depending on the cancer type. Surgery is generally avoided. Oncological treatment is arranged. Surgery is recommended only for certain types of cancer. For example, we recommend resection for lung metastasis of thymoma. If there is a pleural effusion, we drain it with a catheter and perform (talc) pleurodesis.