To explore the CT findings, follow-up changes of primary nodular mass pulmonary mucinous adenocarcinoma, so as to improve the understanding of the disease.

The pathological, clinical and imaging data of 80 patients with primary nodular mass lung mucinous adenocarcinoma confirmed by pathology were retrospectively analyzed. All patients underwent chest CT examination, of which 57 patients underwent enhanced chest CT examination, and 8 patients had follow-up CT with more than 2 weeks interval. Analyze the imaging signs and dynamic CT follow-up changes of the lesions.

There were 7 cases of minimally invasive pulmonary mucinous adenocarcinoma and 73 cases of invasive pulmonary mucinous adenocarcinoma. There were 78 cases with a single lesion and 2 cases with multiple primary lesions. There were 20 cases of mixed ground glass nodules and 60 cases of solid lesions. 69 cases (86.2%) were located under the pleura and 49 cases (61.2%) were located in the lower lobe of the lung.These features accounted for more than 50% of all CT signs in 80 cases, including round shape in 46 cases(57.5%), clear and rough interface in 45 cases(56.2%), lobulation in 70 cases(87.5%), ground-glass opacity sign in 43 cases(53.8%). The density of lesions on non-enhanced CT was lower than that of muscle. There were 19 cases with mild enhancement, 30 cases with moderate enhancement, 8 case with obvious enhancement, 17 cases with non-enhanced liquid areas, and 15 cases with angiographic signs. CT dynamic follow-up changes are diverse, which can remain stable or grow rapidly in the short term, or the solid component will decrease and the ground glass component will increase in the short term, or remain unchanged or grow slowly for a long time.

Primary nodular-mass type pulmonary mucinous adenocarcinoma usually occurs in the lower lobes of the lungs and under the pleura. It is mostly round-shaped, and the tumor-lung interface is clear and rough, often accompanied by lobular signs and ground glass signs. Mainly with mild to moderate enhancement degree .CT dynamic follow-up changes are diverse. Combining the HRCT signs, CT enhancement and follow-up changes of the lesions has certain suggestive significance for the diagnosis of lung mucinous adenocarcinoma.