Our purpose was to evaluate whether pseudocavitation, characterized by round or oval areas of low attenuation in a lesion on computed tomography (CT), can help distinguish adenocarcinoma from other types of non–small cell lung cancer (NSCLC). We also sought to determine whether pseudocavitation is associated with lepidic growth on histopathology.
Materials and Methods:
This retrospective HIPAA-compliant study was approved by our institutional review board. The need for informed consent was waived. CT scans and pathology records from 158 NSCLCs in 149 patients were retrospectively reviewed. The frequency of pseudocavitation was compared among types of NSCLC, specifically adenocarcinoma versus other types of NSCLC. Subgroup analysis of adenocarcinomas was performed to identify any difference in the frequency of pseudocavitation between adenocarcinomas with reported lepidic growth and those without lepidic growth.
There was a significantly greater frequency of pseudocavitation in adenocarcinomas versus other types of NSCLC [19/86 (22.1%) vs. 4/72 (5.6%), P=0.007]. The sensitivity and specificity of the pseudocavitation sign for adenocarcinoma were 0.22 and 0.94, respectively. Among adenocarcinomas, the pseudocavitation sign was more frequent in tumors with lepidic growth versus those without lepidic growth [10/24 (41.7%) vs. 9/62 (14.5%), P=0.015].
Pseudocavitation at CT is more common in primary lung adenocarcinoma than in other types of NSCLC. It is also more common in adenocarcinomas with lepidic growth, suggesting a correlation between the imaging finding of pseudocavitation and the pathologic finding of lepidic growth. As the subtype of NSCLC guides treatment, predicting tumor pathology by imaging may improve diagnostic workup for patients with NSCLC.