Mesothelioma Diagnosis Clinical Knowledge Assessment — Questions and Answers

Question 1: Ultrasound of the chest in mesothelioma is most useful for which clinical application?

Lymph node mapping
Guiding thoracentesis and pleural biopsy (Correct answer)
Mediastinal assessment
Full tumor staging

Correct answer: Guiding thoracentesis and pleural biopsy

Ultrasound is primarily used at the bedside to guide thoracentesis (fluid drainage) and image-guided pleural biopsy safely.

Question 2: Which MRI sequence is most useful for characterizing the relationship of pleural mesothelioma to the diaphragm?

T1-weighted post-contrast
T2-weighted imaging (Correct answer)
Diffusion-weighted imaging
STIR sequence

Correct answer: T2-weighted imaging

T2-weighted MRI provides excellent contrast between tumor and adjacent structures, helping delineate diaphragmatic involvement.

Question 3: CT-guided core needle biopsy of a pleural mass in suspected mesothelioma is preferred over fine needle aspiration (FNA) because:

It is less invasive
It provides faster results
It provides tissue architecture needed for subtyping (Correct answer)
It avoids radiation exposure

Correct answer: It provides tissue architecture needed for subtyping

Core needle biopsy preserves tissue architecture, which is essential for immunohistochemical subtyping (epithelioid vs. sarcomatoid) of mesothelioma.

Question 4: A patient with peritoneal mesothelioma is most likely to present with which of the following?

Hemoptysis and pleurisy
Hematuria and flank pain
Abdominal distension and ascites (Correct answer)
Jaundice and hepatomegaly

Correct answer: Abdominal distension and ascites

Peritoneal mesothelioma typically presents with abdominal distension due to malignant ascites and diffuse peritoneal involvement.

Question 5: What is the significance of the NF2 gene mutation in mesothelioma pathology?

It is found only in pericardial mesothelioma
It indicates asbestos-free etiology
It is one of the most common somatic mutations found in mesothelioma (Correct answer)
It predicts response to immunotherapy

Correct answer: It is one of the most common somatic mutations found in mesothelioma

NF2 (merlin) mutation is among the most frequently identified somatic mutations in malignant mesothelioma, found in approximately 40% of tumors.

Question 6: VEGF (vascular endothelial growth factor) serum levels in mesothelioma are elevated and correlate with:

Sarcomatoid cell type only
Response to surgery
Pleural effusion volume and tumor angiogenesis (Correct answer)
BAP1 mutation status

Correct answer: Pleural effusion volume and tumor angiogenesis

Elevated VEGF promotes tumor angiogenesis and is associated with larger pleural effusions; it has been explored as a therapeutic target in mesothelioma.

Question 7: Which occupational group carries the highest risk of presenting with mesothelioma symptoms?

Healthcare workers
Office administrative workers
Insulation and shipyard workers with asbestos exposure (Correct answer)
Agricultural field workers

Correct answer: Insulation and shipyard workers with asbestos exposure

Insulation workers, shipyard workers, and others with direct asbestos exposure have the highest lifetime risk of developing mesothelioma.

Question 8: Which biomarker found in pleural fluid is used to differentiate malignant from benign pleural effusions?

pH
Mesothelin (Correct answer)
Lactate dehydrogenase (LDH)
Glucose

Correct answer: Mesothelin

Elevated mesothelin levels in pleural fluid support a malignant mesothelioma diagnosis and help distinguish it from benign causes of effusion.

Question 9: Which radiologic sign on chest X-ray suggests mesothelioma has encased and contracted the affected hemithorax?

Bilateral pleural effusions
Apical pleural capping
Contralateral mediastinal shift
Ipsilateral volume loss with pleural thickening (Correct answer)

Correct answer: Ipsilateral volume loss with pleural thickening

Mesothelioma often causes ipsilateral volume loss because the tumor encases and constricts the lung, rather than pushing the mediastinum to the opposite side.

Question 10: Serum osteopontin has been proposed as a mesothelioma screening biomarker in asbestos-exposed individuals because:

It is specific for peritoneal disease
It is only elevated after symptoms begin
It is elevated in asbestos-exposed individuals who develop mesothelioma compared to exposed but disease-free individuals (Correct answer)
It replaces imaging in annual surveillance

Correct answer: It is elevated in asbestos-exposed individuals who develop mesothelioma compared to exposed but disease-free individuals

Serum osteopontin is significantly elevated in asbestos-exposed individuals who develop mesothelioma, suggesting a role in surveillance of high-risk populations.

Question 11: Which characteristic morphological feature differentiates epithelioid mesothelioma from reactive mesothelial hyperplasia on histology?

Mitotic rate alone
Stromal invasion (Correct answer)
Nuclear pleomorphism alone
Cell size

Correct answer: Stromal invasion

Stromal invasion is the definitive histological feature of malignancy; reactive mesothelial cells may appear atypical but do not invade underlying stroma.

Question 12: On CT imaging, which feature is most suggestive of peritoneal mesothelioma?

Single large abdominal mass
Isolated hepatic lesion
Diffuse peritoneal thickening with ascites (Correct answer)
Retroperitoneal lymphadenopathy alone

Correct answer: Diffuse peritoneal thickening with ascites

Peritoneal mesothelioma typically appears on CT as diffuse peritoneal thickening or nodularity accompanied by ascites.

Question 13: Which inflammatory marker ratio is used as a prognostic tool in mesothelioma?

ESR alone
Neutrophil-to-lymphocyte ratio (NLR) (Correct answer)
Ferritin level
Procalcitonin

Correct answer: Neutrophil-to-lymphocyte ratio (NLR)

An elevated neutrophil-to-lymphocyte ratio (NLR) reflects systemic inflammation and immune suppression and is an independent prognostic marker in mesothelioma.

Question 14: Horner's syndrome appearing in a patient with pleural mesothelioma most likely indicates:

Superior vena cava syndrome
Apical tumor involvement with invasion of the sympathetic chain (Correct answer)
Chemotherapy-induced peripheral neuropathy
Paraneoplastic neurological involvement

Correct answer: Apical tumor involvement with invasion of the sympathetic chain

Horner's syndrome (ptosis, miosis, anhidrosis) in mesothelioma results from tumor invasion of the sympathetic chain near the apex of the chest.

Question 15: Which imaging finding would most likely prompt a change from surgical to palliative management in pleural mesothelioma?

Single pleural nodule without invasion
Mediastinal lymph node involvement on PET/CT (Correct answer)
Pleural thickening less than 5 mm
Small ipsilateral pleural effusion

Correct answer: Mediastinal lymph node involvement on PET/CT

Mediastinal nodal involvement (N2 disease) indicates unresectable disease in most staging systems, often redirecting management toward palliative intent.

Question 16: Localized malignant mesothelioma is distinguished from diffuse malignant mesothelioma primarily by:

Cell type — always sarcomatoid
Its discrete, localized mass without diffuse pleural spread (Correct answer)
Requirement for HIPEC treatment
Earlier lymph node involvement

Correct answer: Its discrete, localized mass without diffuse pleural spread

Localized malignant mesothelioma presents as a distinct mass without the diffuse pleural coating typical of diffuse mesothelioma, and is potentially curable with surgery.

Question 17: Which type of chest pain is most characteristically associated with pleural mesothelioma?

Sharp pleuritic pain that worsens with deep inspiration
Central crushing chest pain
Dull, persistent, non-pleuritic chest pain (Correct answer)
Intermittent anginal pain relieved by rest

Correct answer: Dull, persistent, non-pleuritic chest pain

Pleural mesothelioma typically causes a dull, persistent, non-pleuritic chest pain due to direct tumor involvement of the chest wall and parietal pleura.

Question 18: Why is pleural biopsy via Abrams needle less preferred than VATS for mesothelioma diagnosis?

It cannot reach the pleura
It causes more patient discomfort
It requires general anesthesia
It provides smaller, less representative samples with lower diagnostic yield (Correct answer)

Correct answer: It provides smaller, less representative samples with lower diagnostic yield

Blind Abrams needle biopsy has a lower diagnostic yield (~20–40%) compared to VATS, which allows directed biopsies of visible tumor areas.

Question 19: A patient presents with progressive dyspnea and is found to have a large right-sided pleural effusion. After thoracentesis, the fluid rapidly re-accumulates within two weeks. This pattern is most consistent with:

Transudative effusion from heart failure
Malignant pleural effusion from mesothelioma (Correct answer)
Parapneumonic effusion from pneumonia
Chylothorax from lymphatic obstruction

Correct answer: Malignant pleural effusion from mesothelioma

Rapid re-accumulation of pleural fluid after thoracentesis is a hallmark of malignant pleural effusion, commonly seen in mesothelioma.

Question 20: Pleural plaques seen on CT are important in mesothelioma diagnosis because they indicate:

Current active tumor
Autoimmune pleuritis
Prior asbestos exposure (Correct answer)
Bacterial infection

Correct answer: Prior asbestos exposure

Calcified pleural plaques are a marker of prior asbestos exposure and, while benign themselves, raise suspicion for asbestos-related malignancy.

Question 21: MicroRNA-625-3p in pleural effusion has been studied as a mesothelioma biomarker because:

It indicates BAP1 loss
It predicts surgical margins
It is elevated in malignant effusions and may improve cytological diagnosis (Correct answer)
It measures asbestos-induced DNA damage

Correct answer: It is elevated in malignant effusions and may improve cytological diagnosis

MicroRNA-625-3p levels are elevated in pleural fluid from mesothelioma patients and may augment cytological diagnosis in indeterminate cases.

Question 22: A pleural biopsy showing diffuse large B-cell lymphoma cells would be differentiated from mesothelioma by which finding?

Calretinin positivity
CDKN2A deletion
CD20 positivity and cytokeratin negativity (Correct answer)
BAP1 loss

Correct answer: CD20 positivity and cytokeratin negativity

DLBCL expresses B-cell marker CD20 and lacks cytokeratin expression, which is the opposite of mesothelioma's keratin-positive, CD20-negative profile.

Question 23: Benign multicystic peritoneal mesothelioma is distinguished from malignant peritoneal mesothelioma by which feature?

It does not respond to surgery
It is non-invasive and has a favorable prognosis (Correct answer)
It contains sarcomatoid cells
It spreads to the pleura more rapidly

Correct answer: It is non-invasive and has a favorable prognosis

Benign multicystic peritoneal mesothelioma is a non-invasive cystic lesion of the peritoneum with an excellent prognosis compared to its malignant counterpart.

Question 24: What is the role of next-generation sequencing (NGS) in mesothelioma diagnosis?

Measuring mesothelin expression
Identifying actionable mutations and confirming malignancy (Correct answer)
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.

Question 25: Which IHC profile helps distinguish pleural mesothelioma (positive) from metastatic adenocarcinoma (negative)?

MOC-31 positive, D2-40 negative
Calretinin positive, CEA negative (Correct answer)
CEA positive, WT1 negative
TTF-1 positive, calretinin negative

Correct answer: Calretinin positive, CEA negative

Mesothelioma characteristically stains positive for calretinin and negative for CEA, while the reverse pattern is seen in metastatic adenocarcinoma.

Question 26: Solitary fibrous tumor of the pleura (SFTP) is distinguished from mesothelioma by which key feature?

It always occurs in asbestos-exposed workers
It is usually localized and has a pedunculated attachment to the pleura (Correct answer)
It is always malignant
It is diffuse and bilateral

Correct answer: It is usually localized and has a pedunculated attachment to the pleura

SFTP is typically a well-circumscribed, pedunculated, localized mass attached to the pleura by a stalk, in contrast to the diffuse pleural involvement of mesothelioma.

Question 27: Which finding would most strongly suggest mesothelioma over benign asbestos-related pleural disease on CT?

Pleural nodularity with thickening >1 cm (Correct answer)
Costophrenic angle blunting alone
Small free-flowing pleural effusion
Bilateral calcified pleural plaques

Correct answer: Pleural nodularity with thickening >1 cm

Irregular pleural nodularity and thickening greater than 1 cm are hallmarks of malignancy, while bilateral calcified plaques alone indicate asbestos exposure without malignancy.

Question 28: Which malignancy most commonly mimics pleural mesothelioma on imaging and requires IHC for differentiation?

Metastatic lung adenocarcinoma (Correct answer)
Primary pleural lymphoma
Pulmonary carcinoid
Primary lung squamous cell carcinoma

Correct answer: Metastatic lung adenocarcinoma

Metastatic lung adenocarcinoma to the pleura can produce diffuse pleural thickening identical to mesothelioma on imaging, requiring IHC to differentiate.

Question 29: Elevated serum SMRP is most specific for which mesothelioma cell type?

Epithelioid (Correct answer)
Biphasic
Desmoplastic
Sarcomatoid

Correct answer: Epithelioid

SMRP is primarily expressed by epithelioid mesothelioma cells; sarcomatoid tumors express little to no mesothelin, reducing biomarker sensitivity in those cases.

Question 30: Which IHC marker strongly supports synovial sarcoma over sarcomatoid mesothelioma in a chest wall/pleural spindle cell tumor?

TLE1 positivity with SYT-SSX fusion on FISH (Correct answer)
BAP1 loss
Pancytokeratin positivity alone
D2-40 positivity

Correct answer: TLE1 positivity with SYT-SSX fusion on FISH

TLE1 is a sensitive marker for synovial sarcoma, and the SYT-SSX translocation confirmed by FISH definitively distinguishes it from sarcomatoid mesothelioma.

Mesothelioma Diagnosis Clinical Knowledge Assessment

Assesses clinical competency in diagnosing malignant mesothelioma, covering diagnostic imaging, biopsy and pathology, biomarker interpretation, and differential diagnosis from adenocarcinoma and benign conditions.

Questions

35 min

Time Limit

70%

To Pass

Checking for saved progress...

Exam Rules

You can skip questions and return to them later
Flag questions for review before submitting
No feedback shown until you submit the entire exam
Unanswered questions count as wrong — answer everything
10 pretest questions are mixed in and don't affect your score
Timer auto-submits when time runs out
Your progress is auto-saved every 30 seconds