Multiple well-defined, round, basal-predominant nodules of different sizes in a patient with cancer — count, measure the target lesions, and describe the variants (cavitating, calcified, haemorrhagic halo, miliary) that point to the primary.
Orient first
- Haematogenous spread gives random, basal, subpleural nodules.
- Cavitating: squamous cell carcinoma, sarcoma; calcified: osteosarcoma, mucinous adenocarcinoma, treated tumours; haemorrhagic halo: melanoma, choriocarcinoma, angiosarcoma.
- Miliary: thyroid, renal, melanoma.
Acquire the study
- Contrast-enhanced CT chest (thin sections); MIP reconstructions increase detection.
The manoeuvre
- Lung window with MIP slabs: count nodules; size of the largest in mm.
- Distribution: random vs perilymphatic vs centrilobular (helps separate from other causes).
- Target lesions for RECIST (≥ 10 mm, maximum 2 per organ — use the calculator).
- Variants: cavitation, calcification, halo.
- Compare with prior study over the interval.
What confirms it
- New or growing multiple nodules in a patient with a known primary.
What licenses you to exclude it
- A few stable tiny nodules over two years in a patient without cancer are usually benign.
The classic misread
- Calling granulomas metastases in endemic TB regions — calcification and stability help.