Which radiologic features are indicative of malignancy in a solitary pulmonary nodule?

Which radiologic features are indicative of malignancy in a solitary pulmonary nodule?

• A. Diameter >10 mm, upper lobe location, irregular or spiculated borders, no calcifications, a ground-glass appearance, and increasing size over time
• B. Diameter >10 mm with smooth borders in the lower lobes and calcifications, stable size
• C. Diameter ≤5 mm, peripheral location, well-defined rounded border, calcifications, decreasing size
• D. Diameter >20 mm, central location, smooth borders, calcifications, stable size

Answer: (A)

A malignant solitary pulmonary nodule tends to be larger, have irregular or spiculated edges, often lack calcifications, and show growth over time. The described pattern fits best because the nodule is bigger than 10 mm, typically a higher-risk size, and the irregular or spiculated borders reflect invasive growth into surrounding lung tissue. The absence of calcifications removes a common benign clue, and a ground-glass component can be seen with certain adenocarcinomas, especially when there is a solid part and progression over time. Growing size is one of the strongest indicators of malignancy. In contrast, nodules with smooth borders, presence of calcifications (especially in benign patterns), and stability in size over time are much more suggestive of a benign process. Very small nodules, or those with decreasing size, also tend to be less concerning for cancer.

A malignant solitary pulmonary nodule tends to be larger, have irregular or spiculated edges, often lack calcifications, and show growth over time. The described pattern fits best because the nodule is bigger than 10 mm, typically a higher-risk size, and the irregular or spiculated borders reflect invasive growth into surrounding lung tissue. The absence of calcifications removes a common benign clue, and a ground-glass component can be seen with certain adenocarcinomas, especially when there is a solid part and progression over time. Growing size is one of the strongest indicators of malignancy.

In contrast, nodules with smooth borders, presence of calcifications (especially in benign patterns), and stability in size over time are much more suggestive of a benign process. Very small nodules, or those with decreasing size, also tend to be less concerning for cancer.