Patient will present as → a 35-year-old female who was found to have a small (2.5 cm) pulmonary lesion on chest radiograph found incidentally after a screening exam for a positive PPD at work. The patient has no significant past medical history and is asymptomatic.
< 3 cm is a nodule if > 3 cm the lesion is considered a mass
- Smooth well-defined edges are more likely to be benign
- Ill-defined, lobular, or spiculated suggests cancer
- Pulmonary nodules are also known as coin lesions
The goal of initial testing is to estimate the malignant potential of the solitary pulmonary nodule. The first step is a review of plain x-rays and then usually obtain a CT
- Incidental finding on CXR → compare to older CXR if available →
- Send for CT →
- If suspicious (depending on radiographic findings below) will need a biopsy
- Ill-defined, lobular, or spiculated suggests cancer
- If not suspicious < 1 cm it should be monitored at 3 mo, 6 mo, and then yearly for 2 yr
- Calcification, smooth well-defined edges, suggests benign disease
The Fleischner Society pulmonary nodule recommendations pertain to the follow-up and management of indeterminate pulmonary nodules detected incidentally on CT and are published by the Fleischner Society.
Solid nodules
Single
Single solid nodule <6 mm (<100 mm3)
- low-risk patients: no routine follow-up required
- high-risk patients: optional CT at 12 months (particularly with suspicious nodule morphology and/or upper lobe location; see “risk assessment” below)
Solitary solid nodule 6-8 mm (100-250 mm3)
- low-risk patients: CT at 6-12 months, then consider CT at 18-24 months
- high-risk patients: CT at 6-12 months, then CT at 18-24 months
Solitary solid nodule >8 mm (>250 mm3)
- low-risk and high-risk patients: consider CT at 3 months, PET/CT, or tissue sampling
Multiple
Multiple solid nodules <6 mm (<100 mm3)
- low-risk patients: no routine follow-up required
- high-risk patients: optional CT at 12 months
Multiple solid nodules >6 mm (>100 mm3)
- low-risk patients: CT at 3-6 months, then consider CT at 18-24 months
- high-risk patients: CT at 3-6 months, then CT at 18-24 months
When multiple nodules are present, the most suspicious nodule should guide further individualized management.
Subsolid nodules
Single
Single ground glass nodule <6 mm (<100 mm3)
- no routine follow-up required
Single ground glass nodule ≥6 mm (>100 mm3)
- CT at 6-12 months, then if persistent, CT every 2 years until 5 years
Single part-solid nodule ≥6 mm (>100 mm3)
- CT at 3-6 months, then if persistent and solid component remains <6 mm, annual CT until 5 years
Multiple
Multiple subsolid nodules <6 mm (<100 mm3)
- CT at 3-6 months, then if stable consider CT at 2 and 4 years in high-risk patients
Multiple subsolid nodules ≥6 mm (>100 mm3)
- CT at 3-6 months, then subsequent management based on the most suspicious nodule(s)
The guideline does not apply to lung cancer screening, patients younger than 35 years, or patients with a history of primary cancer or immunosuppression.
Radiographic characteristics help define the malignant potential of a solitary pulmonary nodule
- Growth rate is determined by comparison with previous chest x-ray or CT, if available
- A lesion that has not enlarged in ≥ 2 yr suggests a benign etiology
- Tumors that have volume doubling times from 21 to 40 days are likely to be malignant
- Small nodules (< 1 cm) should be monitored at 3 mo, 6 mo, and then yearly for 2 yr
- Calcification suggests benign disease, particularly if it is central (tuberculoma, histoplasmoma), concentric (healed histoplasmosis), or in a popcorn configuration (hamartoma).
- Margins that are spiculated or irregular (scalloped) are more indicative of cancer
- Diameter < 1.5 cm strongly suggests a benign etiology; diameter > 5.3 cm strongly suggests cancer. However, nonmalignant exceptions include lung abscess, Wegener's granulomatosis, and hydatid cyst
Management depends on radiological findings - if malignant potential should be biopsied or if benign-appearing can be followed as outlined in the previous section
Chest X-ray showing a solitary pulmonary nodule (indicated by a black box) in the left upper lobe
Question 1 |
CT scan of the chest | |
Needle biopsy of the lesion Hint: A needle biopsy would be indicated for a person greater than 35 years old and/or with a history of smoking to evaluate a solitary pulmonary nodule. | |
Positron emission tomography of the chest Hint: Positron emission tomography (PET scan) would be indicated if the CT scan was nonconclusive. | |
Fiberoptic bronchoscopy Hint: Fiberoptic bronchoscopy would be indicated only in the presence of a history of tobacco use or if the lesion was suggestive of malignancy. |
Question 2 |
Bone scan Hint: Bone scanning is indicated for evaluation of bone metastases, most commonly secondary to cancer of the breast or prostate. | |
Thoracotomy Hint: Diagnostic thoracotomy is indicated for biopsy of the lesion should the CT scan of the chest indicate a suspicious malignant lesion that is inaccessible to thoracoscopy. | |
Mediastinoscopy Hint: Mediastinoscopy can be utilized to further evaluate any enlarged mediastinal lymph nodes that may be found on the CT scan of the chest, but is not indicated prior to the CT scan. | |
CT scan of chest |
Question 3 |
Review old radiographs | |
Order chest CT | |
Schedule lung biopsy Hint: See A for explanation. | |
Prepare for surgical lung resection Hint: See A for explanation. |
|
List |
References: Merck Manual · UpToDate
