Mesothelioma Therapy Diagnosis and Biomarkers for Mesothelioma 1 — Questions and Answers
Question 1: Which imaging modality is typically performed first when mesothelioma is clinically suspected?
- PET-CT scan
- MRI of the chest
- Chest X-ray (Correct answer)
- Echocardiogram
Correct answer: Chest X-ray
Chest X-ray is the standard initial imaging study when mesothelioma is suspected, commonly revealing unilateral pleural effusion or pleural thickening.
Question 2: Which CT finding is most characteristic of pleural mesothelioma?
- Bilateral hilar lymphadenopathy
- Circumferential pleural thickening encasing the lung (Correct answer)
- Solitary pulmonary nodule in the upper lobe
- Bilateral ground-glass opacities in the lower lobes
Correct answer: Circumferential pleural thickening encasing the lung
Circumferential pleural thickening that encases the lung is the classic CT appearance of pleural mesothelioma, distinguishing it from localized lung cancer.
Question 3: What is the primary role of PET-CT in the evaluation of mesothelioma?
- It serves as the gold standard for initial tissue diagnosis
- It assesses metabolic activity of pleural disease and detects distant metastases for staging (Correct answer)
- It replaces the need for tissue biopsy
- It directly measures pleural fluid composition and volume
Correct answer: It assesses metabolic activity of pleural disease and detects distant metastases for staging
PET-CT assesses the metabolic activity of pleural thickening, evaluates regional lymph nodes, and detects occult distant metastases, making it essential for accurate staging.
Question 4: Which MRI sequences are most useful for evaluating diaphragmatic and chest wall invasion in mesothelioma?
- T1-weighted without contrast only
- T2-weighted and contrast-enhanced T1-weighted sequences (Correct answer)
- Diffusion-weighted imaging alone
- Proton density sequences
Correct answer: T2-weighted and contrast-enhanced T1-weighted sequences
T2-weighted and contrast-enhanced T1-weighted MRI sequences provide superior soft tissue contrast and enhancement patterns that best delineate invasion of the diaphragm and chest wall.
Question 5: What is the most common radiographic finding on initial chest X-ray in patients with pleural mesothelioma?
- Spontaneous pneumothorax
- Calcified pleural plaques
- Unilateral pleural effusion (Correct answer)
- Bilateral mediastinal widening
Correct answer: Unilateral pleural effusion
Unilateral pleural effusion is the most common initial radiographic finding in pleural mesothelioma, often prompting further diagnostic workup.
Question 6: Which nuclear medicine study is most useful for detecting occult distant metastases in mesothelioma staging?
- Technetium-99m bone scintigraphy
- FDG-PET scan (Correct answer)
- Gallium-67 scan
- MIBI myocardial perfusion scan
Correct answer: FDG-PET scan
FDG-PET scan is the most sensitive nuclear medicine study for identifying metabolically active distant metastases and comprehensively assessing disease extent in mesothelioma.
Question 7: Which CT feature is most suggestive of malignant rather than benign pleural disease?
- Small bilateral pleural effusions
- Pleural thickening greater than 1 cm with nodularity or mediastinal pleural involvement (Correct answer)
- Isolated pleural calcifications without associated thickening
- Unilateral blunting of the costophrenic angle alone
Correct answer: Pleural thickening greater than 1 cm with nodularity or mediastinal pleural involvement
Pleural thickening exceeding 1 cm with nodularity or involvement of the mediastinal pleura on CT is highly suggestive of malignant pleural disease, including mesothelioma.
Mesothelioma Therapy Diagnosis and Biomarkers for Mesothelioma 1
Which imaging modality is typically performed first when mesothelioma is clinically suspected?