solitary pulmonary nodule


solitary pulmonary nodule

(sol'i-tār-ē pul'mō-nār-ē), an isolated density usually smaller than 3 cm in diameter found on a plain chest radiograph (some clinicians would include CT scan), completely surrounded by aerated lung and not associated with atelectasis or adenopathy.
A rounded, circumscribed nodule measuring < 4 cm that may be surrounded by well-aerated pulmonary parenchyma, which often—about half of cases identified in the US—appears as an incidental finding in an otherwise unremarkable plain chest X-ray
Diagnosis Age, smoking history, geographic location, history of previous malignancy
Aetiology Infection (abscesses, aspergilloma, bacteria, coccidioidomycosis, echinococcal cysts, Dirofilaria immitis, histoplasmosis, TB), benign masses (bronchial adenoma, chondroma, diaphragmatic hernia, benign mesothelioma), neurogenic tumour, sarcoidosis, sclerosing hemangioma, Wegener’s granulomatosis, rheumatoid nodules; malignant masses—1º lung cancer—which comprise 35%, metastases ± 10%, sarcoma, myeloma, Hodgkin’s disease, choriocarcinoma

solitary pulmonary nodule

Any isolated mass lesion found in the lung, usually during an x-ray study performed for another reason. Most small masses that are identified in this way are benign, although smokers, patients already known to have cancer in another organ system, and older patients have an increased risk that a solitary nodule will be a new malignancy or a metastasis from another source.

Patient care

The first step in evaluating a solitary lung nodule is to search for prior chest x-ray films. If the nodule can be found on films done many months or years earlier and has not changed in size, shape, or calcification, it is likely to be benign and can be followed conservatively. Newly identified lesions within the lung that were not previously present usually are evaluated with further studies, such as computed tomography of the lungs, sputum studies, or biopsies.

See also: nodule