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
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
CT scan of the chest
Needle biopsy of the lesion
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
Positron emission tomography (PET scan) would be indicated if the CT scan was nonconclusive.
Fiberoptic bronchoscopy would be indicated only in the presence of a history of tobacco use or if the lesion was suggestive of malignancy.
Bone scanning is indicated for evaluation of bone metastases, most commonly secondary to cancer of the breast or prostate.
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 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
Review old radiographs
Order chest CT
Schedule lung biopsy
See A for explanation.
Prepare for surgical lung resection
See A for explanation.