Can pseudocavitation in lung tumors predict the diagnosis of adenocarcinoma with lepidic growth?

To determine the prevalence of pseudocavitation in lung tumors and whether its presence makes it possible to predict the diagnosis of adenocarcinoma with lepidic growth.

We retrospectively reviewed chest CT studies for 212 consecutive lung tumors included in a CT perfusion database and for 351 consecutive adenocarcinomas diagnosed between July 2007 and September 2017. Two radiologists blinded to the pathology report determined whether air cysts were present in the tumors, excluding lesions with necrosis and those surrounded by bullae or emphysema. We analyzed whether the presence of pseudocavitation was associated with the histologic type, size, or EGFR positivity of the tumor as well as with the age or sex of the patient. We also evaluated the relationship with the histologic subtype of the tumor in patients who underwent surgery. We used the chi-square test for categorical variables and logistic regression for continuous variables.

Pseudocavitation was present in 15% of the tumors and was significantly more common in adenocarcinomas (24.1%), p=0.003, although it was also observed in 9.8% of the epidermoid carcinomas and in 3% of the microcytic carcinomas. For the diagnosis of adenocarcinoma, the presence of pseudocavitation yielded 92.4% specificity, 24% sensitivity, 73.3% PPV, 58.4% NPV, and 37.6% accuracy. In the resected adenocarcinomas, 65% of the tumors with pseudocavitation had lepidic growth; the prevalence of pseudocavitation was 40.6% in tumors with lepidic growth, 31.5% in those with acinar growth, and 33% in those with papillary growth. Pseudocavitation was significantly more common in women (29%); no differences were found with respect to age, size, or EGFR positivity.

Pseudocavitation is more common in adenocarcinomas with lepidic growth and in women.