The Solitary Pulmonary Nodule

Abstract

which becomes increasingly frequent as the number of CT examinations rises. The workup of these nodules is rather expensive and emotionally burdensome, especially when the patient has risk factors for bronchial carcinoma. SPN are noted in up to 0.2% of chest radiographs [4,5] , whereas 27.3% of patients undergoing the National Lung Screening Trial (NLST) had at least one SPN with a diameter >4 mm on their CT examination [6] . Differential diagnosis is extensive, but the majority of the identified nodules are comprised of granulomas, lung cancers and hamartomas [7,8] . Against the background of potential malignancy and the poor prognosis of advanced lung cancer, rapid identification and resection of malignant SPN is crucial, leading to a 5-year survival rate of 60-80% in stage I [9, 10] non-small-cell lung carcinoma (NSCLC). Nonetheless, even in a population at high-risk for lung cancer, the vast majority of small SPN are benign. In the lung screening study of the National Cancer Institute, the lung cancer diagnosis rates were <5, 21.3 and 34.5% for nodules <10, 11-19 and >20 mm in diameter, respectively [11] . The management of an SPN should aim to identify malignancy as fast as possible in order to provide the option of potentially curative surgical treatment whilst avoiding invasive diagnostic procedures in the case of benign lesions. Numerous articles have been published addressing the optimal strategy of evaluating individuals with lung nodules, including the most recently published ACCP guideline for the diagnosis and management of lung cancer [12] . Those strategies are generally based on the individual's risk of developing lung cancer, the pulmonary nodule characteristics and the capability of the current diagnostic and therapeutic approaches. Key WordsSolitary pulmonary nodule · Lung cancer · Screening · Management · Biopsy · Surgical approaches Abstract Due to the high etiological diversity and the potential for malignancy, pulmonary nodules represent a clinical challenge, becoming increasingly frequent as the number of CT examinations rises. The topic gains even more importance as clear evidence for the effectiveness of CT screening was provided by the National Lung Screening Trial (NLST). Yet, the results were tempered by the high false-positive rate and the requirement of performing further diagnostic procedures. The management of those detected solitary pulmonary nodules is currently based on the individuals' risk of developing lung cancer, the pulmonary nodule characteristics and the capability of diagnostic and therapeutic approaches.

Differential diagnosis of solitary pulmonary nodules with dual-source spiral computed tomography

“…Tumor cells gained the capacity for infiltrative growth along alveolar walls, lymphatic vessels, and blood vessels and this was the main factor contributing to the formation of spicule signs (17). The causes of pleural indentation include (18), fibrotic contraction within the tumor body, accompanied or unaccompanied by pleural thickening and adhesion. Tumors can directly invade the pleural edge, and the affected direction of the pleural indentation sign was identical with the direction of bronchial blood vessel bundles of the pulmonary lobe where the lump was located.…”

Use of PET/CT to aid clinical decision-making in cases of solitary pulmonary nodule: a probabilistic approach

“…A solitary pulmonary nodule (SPN) is a round or oval pulmonary opacity of up to 3 cm in diameter, surrounded by normal lung parenchyma, that is not accompanied by on its pre-test probability of malignancy (1,4,5) . Cases with low probability of malignancy (< 5%) are usually managed by active surveillance, whereas those with high probability (> 65%) biopsy or surgery is indicated (1,5) . Cases with intermediate probability of malignancy are usually biopsied for diagnostic clarification (6) .…”

“…However, biopsy is an invasive procedure that can lead to a significant number of false-negative results (7) . The use of PET/CT with 18 F-FDG ( 18 F-FDG-PET/CT) can help to define the management of intermediate cases by reclassifying them as having low, intermediate, or high probability of malignancy (1) , thus reducing the number of invasive procedures and the total cost of treatment (8) . However, there are no studies evaluating the frequency with which 18 F-FDG-PET/CT determines a change in the probability of malignancy classification of SPNs, from intermediate to low or high.…”

Navigation Bronchoscopy-Guided Radiofrequency Ablation for Nonsurgical Peripheral Pulmonary Tumors

“…However, not all patients are eligible for surgical resection due to comorbidities or other contraindications. Stereotactic body radiotherapy and radiofrequency ablation (RFA) are recommended for patients medically inoperable as local therapy [4,5] . Stereotactic body radiotherapy is an effective, noninvasive treatment modality but is limited by respiratory movements, requirements for multiple treatments, cost, and the complication of radiation pneumonitis.…”