Mesothelioma Diagnosis Biomarkers and Lab Tests 2 — Questions and Answers
Question 1: Which laboratory finding in pleural fluid analysis is characteristic of a malignant exudative effusion?
- High LDH and high protein (Correct answer)
- Low LDH and low protein
- Low glucose and high amylase
- Normal LDH and low pH
Correct answer: High LDH and high protein
Malignant pleural effusions are exudates characterized by high LDH (>200 IU/L) and high protein (>3 g/dL) using Light's criteria.
Question 2: Which complete blood count (CBC) finding is associated with advanced mesothelioma and poor prognosis?
- Thrombocytosis (Correct answer)
- Neutropenia
- Eosinophilia
- Lymphocytosis
Correct answer: Thrombocytosis
Paraneoplastic thrombocytosis (elevated platelet count) is common in advanced mesothelioma and is associated with poor survival outcomes.
Question 3: What does an elevated serum CRP (C-reactive protein) indicate in the context of mesothelioma?
- Active systemic inflammation associated with worse prognosis (Correct answer)
- Presence of sarcomatoid differentiation
- Response to chemotherapy
- Benign reactive pleural disease
Correct answer: Active systemic inflammation associated with worse prognosis
Elevated CRP reflects tumor-driven systemic inflammation in mesothelioma and is an independent predictor of poor prognosis.
Question 4: Hyaluronan (hyaluronic acid) levels are elevated in pleural fluid of mesothelioma patients. This is because:
- Mesothelioma cells produce large amounts of hyaluronan (Correct answer)
- Bacteria in the pleural space produce it
- Lung cancer metastases secrete it
- It reflects liver dysfunction
Correct answer: Mesothelioma cells produce large amounts of hyaluronan
Malignant mesothelial cells actively secrete hyaluronan into pleural fluid, and markedly elevated levels support a mesothelioma diagnosis.
Question 5: Which germline mutation significantly increases the lifetime risk of developing mesothelioma?
- BAP1 mutation (Correct answer)
- BRCA1 mutation
- MLH1 mutation
- RB1 mutation
Correct answer: BAP1 mutation
Germline BAP1 mutations define the BAP1 tumor predisposition syndrome, which markedly increases the risk of mesothelioma, uveal melanoma, and other cancers.
Question 6: What is the role of next-generation sequencing (NGS) in mesothelioma diagnosis?
- Identifying actionable mutations and confirming malignancy (Correct answer)
- Measuring mesothelin expression
- Assessing asbestos burden in tissue
- Replacing IHC for routine diagnosis
Correct answer: Identifying actionable mutations and confirming malignancy
NGS identifies somatic mutations (e.g., BAP1, NF2, CDKN2A) that confirm malignancy and may reveal targetable alterations for clinical trials.
Mesothelioma Diagnosis Biomarkers and Lab Tests 2
Which laboratory finding in pleural fluid analysis is characteristic of a malignant exudative effusion?