Nodules/Masses

Question 1

Nodule with fat attenuation

Answer 1

• Hamartoma - popcorn calcs, (-40 to -120 HU); no increase on FDG/PET
• Fat pneumonia - mainly in lower lung bases; large and spiculated

Question 2

Lobulated, solitary nodule

Answer 2

• Bronchogenic cancer i.e.: adenocarcinoma - doubling time, size, and borders determine malignant potential (double time is most concerning)
• Hamartoma
• Granuloma
• Round pneumonia
• Callus around rib

Question 3

Well-defined nodule of similar density to muscle

Answer 3

• Granuloma
• Hamartoma
• Adenocarcinoma spectrum
• Carcinoid tumour
• Mets

Question 4

Soft tissue hilar nodule with previous osteosarcoma

Answer 4

• Mets - 10% are solitary mets (colon ca, melanoma, RCC, testicular, sarcoma)
• Adenocarcinoma spectrum
• Fungal infection
• Carcinoid tumour (if endobronchial)
• Inflammatory myofibroblastic tumour

Question 5

Mildly enhancing bronchial soft tissue mass with atelectasis

Answer 5

• Carcinoid tumour - neuroendocrine tumours; round, lobulated, well-defined and close prox to bronchus; eccentric calcs; mild enhancement
• SCC
• Mets
• Minor salivary gland tumours
• Granuloma
• Hamartoma

Question 6

Calcified lesion in bronchus with post-obstructive atelectasis

Answer 6

• Foreign body
• Broncholithiasis
• Carcinoid tumour

Question 7

Solitary cavitary lesion with lymphadenopathy

cavitary = round/ovoid lesion containing air with >4mm wall thickness

Answer 7

• Squamous cell carcinoma (usually cavitate)
• Mets
• Infection (bacterial, fungal, parasitic)
• Wegener’s
• Churgg-Strauss
• Sequestration

Question 8

Multiple cavitary nodules with ground glass rims/halo (due to hemorrhage)

Answer 8

• Septic emboli - infectious hx
• Angioinvasive aspergillus - immune compromised hx
• Mets (melanoma, angiosarcoma)
• Wegener’s
• Churgg-Strauss

Question 9

Numerous tiny cavitary nodules “Cheerio sign”

Answer 9

• Septic emboli
• Fungal
• Adenocarcinoma spectrum
• Mets (other adenocarcinoma)
• Vasculitis
• Langerhans cell histiocytosis