Diagnostic utility of cryobiopsy for invasive mucinous lung adenocarcinoma

Invasive mucinous lung adenocarcinoma (IMA) is challenging to diagnose via bronchoscopy due to its distinct histopathological characteristics, including poorly atypical tumor cells with abundant mucins. Given that cryobiopsy facilitates high-quality and quantity tissue sampling, we hypothesized that it could improve diagnostic success. This retrospective study aimed to determine whether cryobiopsy is a valid diagnostic tool for IMA.

We retrospectively reviewed consecutive patients who underwent surgical resection for lung cancer at our institution between March 2017 and July 2024. Among them, patients diagnosed with IMA were selected. Those who had undergone a diagnostic biopsy for peripheral pulmonary lesions (PPLs) were included in the study. These patients were divided into two groups: cryo and conventional, based on whether cryobiopsy was performed. The diagnostic yield and safety profiles of both groups were compared.

Of 5,053 surgeries for lung cancer, 201 (4.0%) were diagnosed with IMA. Among them, 106 patients who had undergone bronchoscopy for PPLs were included in the analyses: 46 in the cryo group and 60 in the conventional group. The diagnostic yield was significantly higher in the cryo group than in the conventional group (93.5% vs. 73.3%, P=0.01). Multivariable analysis showed cryobiopsy was significantly associated with higher yield [adjusted odds ratio (OR), 5.07; 95% confidence interval (CI): 1.33-19.40; P=0.02]. Although not fatal, complications like bleeding and pneumonia were more frequent in the cryo group.

Cryobiopsy is a valid technique for making a diagnosis of IMA.