Definition and Etiology
- ♦
Solitary pulmonary nodule (SPN)
- ▴
No standard definition is available for SPN. Size criteria vary, but they are usually considered smaller than 3 cm in diameter. Other definitions include characteristics of density on computed tomography (CT) imaging and the absence of cavitation and air bronchograms leading to lesion.
- ▴
There must be an absence of additional radiographic findings on imaging (e.g., no lymphadenopathy, other nodules).
- ▴
SPNs are within the lung parenchyma and either peripheral or central within the lung, often determining the operative approach.
- ▴
- ♦
The causes of SPNs are many:
- ▴
Malignant processes comprise 70% to 80% of SPNs.
- •
Non–small cell lung cancer
- •
Small cell lung cancer (rarely)
- ▪
Metastatic lesions to the lung (e.g., sarcoma, colon cancer, breast cancer, renal cell cancer) can present as SPN, although are often found as multiple nodules.
- ▪
- •
Pulmonary carcinoid tumors
- •
- ▴
Infectious
- •
Infectious granulomas (e.g., histoplasmosis, coccidioidomycosis, blastomycosis, aspergillosis)
- •
Mycobacterium spp.
- •
Pneumocystis (immunocompromised patients)
- •
- ▴
Benign
- •
Hamartoma
- •
Lipoma, leiomyoma
- •
Noncalcified lymph node
- •
- ▴
Step 1
Surgical Anatomy
- ♦
Location of the SPN within lung parenchyma is critical in planning the resection of the nodule.
- ▴
Peripheral nodules allow for wedge resection ( Fig. 2-1 ). With peripheral pulmonary nodules, a margin must be maintained around the lesion and the lesion not compromised with the resection.
Figure 2-1
- ▴
More central nodules may require anatomic resection ( Fig. 2-2 ) in the form of either a lobectomy or segmentectomy.
Figure 2-2
- ▴
Step 2
Preoperative Considerations
- ♦
Several standardized management algorithms are available; included here is the Massachusetts General Hospital algorithm ( Fig. 2-3 ).
- ▴
If available, all current imaging must be compared with any previous imaging.
- •
It allows for assessment of growth or change in the characteristics of the nodule. With an increase in size, one must consider intervention in the form of resection.
- •
With no previous imaging available, the first choice is CT, and a thorough clinical evaluation always includes a history of malignancy and current and previous tobacco history.
- •
Positron emission tomography may have a role in the evaluation of SPNs larger than 1 cm in diameter, with a reasonably high sensitivity for malignancy but a low specificity.
- •
Figure 2-3
- ▴
- ♦
Preoperative localization of lesion (video-assisted thoracoscopic surgery [VATS])
- ▴
It may be difficult to visualize or palpate the nodule during the VATS procedure.
- ▴
Preoperative guidance can come in several forms, often placed before the procedure:
- •
CT-guided wire-hook placement
- •
Placement of metallic microcoils
- •
Navigational bronchoscopy
- •
Percutaneous staining of lesion with methylene blue
- •
Intraoperative ultrasound guidance
- •
Transthoracic injection of radiolabeled tracer with intraoperative localization
- •
Intraoperative real-time CT imaging
- •
- ▴
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
