MCQs: Low-Density Lymphadenopathy
1. What is the most common cause of low-density lymphadenopathy in the chest?
A. Sarcoidosis
B. Tuberculosis
C. Amyloidosis
D. Castleman disease
Answer: B. Tuberculosis
Comment: Tuberculosis frequently causes caseating necrosis in lymph nodes, leading to hypodense or low-density appearance on imaging.
“Caseating necrosis within lymph nodes is a hallmark of tuberculosis, resulting in hypodense regions on imaging.”
Reference: Radiopaedia: Necrotic Lymph Nodes
2. Which imaging feature is most indicative of necrotic lymph nodes?
A. Rim enhancement on contrast-enhanced CT
B. Uniform density within the lymph node
C. Diffuse calcifications
D. Hyperechogenicity on ultrasound
Answer: A. Rim enhancement on contrast-enhanced CT
Comment: Rim enhancement on CT is a classic feature of necrotic lymph nodes, often seen in infections or malignancies.
“Necrotic lymph nodes typically demonstrate central hypodensity with rim enhancement on contrast-enhanced CT.”
Reference: PubMed: Necrotic Lymphadenopathy
3. Infections such as tuberculosis cause low-density lymphadenopathy through which mechanism?
A. Amyloid deposition
B. Caseating necrosis
C. Lipid accumulation
D. Cystic transformation
Answer: B. Caseating necrosis
Comment: Caseating necrosis is caused by granulomatous inflammation, leading to central low-density areas in lymph nodes.
“Caseating necrosis, often associated with granulomatous infections like tuberculosis, results in low-density lymph nodes on imaging.”
Reference: Radiographics: Granulomatous Infections
4. Which of the following malignancies most commonly causes low-density lymphadenopathy?
A. Papillary thyroid carcinoma
B. Lymphoma
C. Squamous cell carcinoma
D. Small cell lung cancer
Answer: B. Lymphoma
Comment: Lymphoma often causes low-density lymphadenopathy due to necrosis or liquefaction within involved nodes.
“Lymphoma is a common cause of low-density lymphadenopathy, reflecting areas of necrosis or fluid accumulation within the nodes.”
Reference: Radiopaedia: Lymphoma Imaging
5. Which imaging modality is most useful for differentiating benign from malignant low-density lymphadenopathy?
A. MRI
B. High-resolution CT (HRCT)
C. PET-CT
D. Ultrasound
Answer: C. PET-CT
Comment: PET-CT is highly effective for distinguishing benign from malignant lymphadenopathy by assessing metabolic activity.
“PET-CT is invaluable in evaluating low-density lymphadenopathy, with high FDG uptake indicating malignancy or active infection.”
Reference: PubMed: PET-CT in Lymphadenopathy
6. What is the primary cause of cystic transformation in lymph nodes?
A. Congenital lymphangioma
B. Sarcoidosis
C. Fungal infections
D. Metastatic carcinoma
Answer: A. Congenital lymphangioma
Comment: Cystic transformation is commonly seen in congenital lymphangiomas or as a result of chronic inflammation.
“Cystic transformation in lymph nodes may occur in congenital conditions such as lymphangiomas or chronic inflammatory processes.”
Reference: Radiographics: Cystic Lymphadenopathy
7. Which of the following conditions is associated with low-density lymphadenopathy due to lipid infiltration?
A. Sarcoidosis
B. Castleman disease
C. Amyloidosis
D. Hodgkin’s lymphoma
Answer: B. Castleman disease
Comment: Castleman disease can cause low-density lymphadenopathy due to lipid or proteinaceous infiltration within nodes.
“Castleman disease is characterized by lymphadenopathy, with occasional low-density regions due to lipid-rich infiltrates.”
Reference: Radiopaedia: Castleman Disease
8. In amyloidosis, what is the primary cause of low-density lymphadenopathy?
A. Caseating necrosis
B. Proteinaceous infiltration
C. Cystic transformation
D. Granulomatous inflammation
Answer: B. Proteinaceous infiltration
Comment: Amyloidosis leads to protein deposition within lymph nodes, causing low-density areas on imaging.
“Amyloidosis causes low-density lymphadenopathy due to the deposition of proteinaceous material in nodal tissue.”
Reference: Radiographics: Amyloidosis
9. Which finding suggests metastatic disease in low-density lymphadenopathy?
A. Central hypodensity with rim enhancement
B. Eccentric calcifications
C. Uniform low attenuation
D. Peripheral hyperattenuation
Answer: B. Eccentric calcifications
Comment: Eccentric calcifications in low-density lymph nodes often indicate metastatic disease or post-treatment changes.
“Eccentric calcifications are associated with metastatic lymphadenopathy, reflecting dystrophic calcification within nodes.”
Reference: Radiopaedia: Metastatic Calcifications
10. Which of the following infections is most commonly associated with low-density lymphadenopathy?
A. Sarcoidosis
B. Tuberculosis
C. Epstein-Barr virus (EBV)
D. Histoplasmosis
Answer: B. Tuberculosis
Comment: Tuberculosis is a frequent cause of low-density lymphadenopathy, particularly in endemic regions, due to caseating necrosis.
“Low-density lymphadenopathy in tuberculosis results from caseating necrosis, commonly seen in endemic areas.”
Reference: Radiopaedia: Tuberculosis Imaging