Spiculated Lung Nodule
A spiculated lung nodule is a term you may see on a radiology report after having a chest CT scan or X-ray. This description refers to a lung nodule— a small, round, or irregular mass in the lung— that has spiky or radiating edges. Unlike smooth or well-defined nodules, a spiculated appearance can be concerning because it may suggest an underlying malignant process. However, not all spiculated nodules are cancerous.
Understanding the significance of a spiculated lung nodule can help guide further medical decisions, including whether additional imaging or a biopsy is needed.
What Does a Spiculated Lung Nodule Look Like on Imaging?
Radiologists identify spiculated nodules by their irregular, star-like borders that extend outward from the central mass. This appearance can be seen on:
- Chest X-rays: Spiculated nodules may appear as irregularly shaped opacities but are harder to detect due to overlapping structures in the lungs.
- CT scans: A CT scan provides a detailed, cross-sectional view of the lungs, making it the preferred method for assessing nodule shape, size, and spiculation.
In my practice, I often see patients referred for further evaluation of a nodule that is seen on chest X-rays. A CT scan is usually needed because a chest X-ray can not completely evaluate the edges and tissue composition of a nodule.
Causes of Spiculated Lung Nodules
Several conditions can cause a lung nodule to develop spiculated features, including:
Lung Cancer
A spiculated lung nodule is considered a high-risk feature for malignancy. Many lung cancers, especially adenocarcinoma, present with this type of irregular border due to tumor infiltration into surrounding lung tissue.
Benign Causes
Not all spiculated nodules are cancerous. Some inflammatory and infectious processes can also create a spiculated appearance, including:
- Granulomas: Past infections, such as tuberculosis or fungal infections, can leave behind calcified nodules with irregular edges.
- Scar tissue: Lung scarring from previous infections or conditions like pulmonary fibrosis can mimic malignancy.
- Active infections and inflammatory disease like fungal infection or sarcoidosis.
- Hamartomas: benign tumors that can sometimes have irregular margins
How Do Radiologists Evaluate a Spiculated Lung Nodule?
Size Matters
The size of the nodule is an important factor. Smaller nodules, particularly those under 6 mm, are less likely to be cancerous, whereas those over 10 mm have a higher malignancy risk.
Growth Over Time
A stable nodule over two years is usually benign. If a nodule grows between imaging studies, it raises suspicion for malignancy.
Density and Composition
- Solid nodules with spiculated edges are more concerning than fat containing nodules.
- Calcifications within the nodule can suggest a benign cause, such as a healed granuloma.
PET Scan for Further Assessment
If a nodule is suspicious, a positron emission tomography (PET) scan may be used. Cancerous nodules tend to show increased metabolic activity, meaning they look brighter on PET scans.
Next Steps: What Happens After a Spiculated Nodule Is Found?
Follow-Up Imaging
If a spiculated nodule is small and not clearly cancerous, doctors may recommend serial CT scans to monitor for changes.
Biopsy or Further Testing
If a nodule is large, growing, or highly suspicious, a biopsy may be necessary. This can be done through:
- CT-guided needle biopsy
- Bronchoscopy with biopsy
- Surgical removal in some cases
Multidisciplinary Review
Some cases are discussed in a tumor board with specialists in radiology, pulmonology, and oncology to determine the best course of action.
Key Takeaways: Should You Be Concerned?
A spiculated lung nodule is a finding that requires careful evaluation, but it is not always cancer. The next steps depend on:
- Size and shape
- Growth over time
- Patient risk factors (e.g., smoking history, age, prior infections)
If you or a loved one has been diagnosed with a spiculated lung nodule, it is important to have a discussion with your doctor about next steps. Early detection of spiculated nodules plays an important role in successful treatment outcomes.
References:
- https://go2.org/wp-content/uploads/2017/09/
- https://my.clevelandclinic.org/health/diseases/14799-pulmonary-nodules
- https://www.atsjournals.org/doi/10.1164/rccm.201104-0679CI