Clinical, pathological, and radiological characteristics of solitary ground-glass opacity lung nodules on high-resolution computed tomography

Abstract

Background: Lung nodules are being detected at an increasing rate year by year with high-resolution computed tomography (HRCT) being widely used. Ground-glass opacity nodule is one of the special types of pulmonary nodules that is confirmed to be closely associated with early stage of lung cancer. Very little is known about solitary ground-glass opacity nodules (SGGNs). In this study, we analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT.

Methods: A total of 95 resected SGGNs were evaluated with HRCT scan. The clinical, pathological, and radiological characteristics of these cases were analyzed.

Results: Eighty-one adenocarcinoma and 14 benign nodules were observed. The nodules included 12 (15%) adenocarcinoma in situ (AIS), 14 (17%) minimally invasive adenocarcinoma (MIA), and 55 (68%) invasive adenocarcinoma (IA). No patients with recurrence till date have been identified. The positive expression rates of anaplastic lymphoma kinase and ROS-1 (proto-oncogene tyrosine-protein kinase ROS) were only 2.5% and 8.6%, respectively. The specificity and accuracy of HRCT of invasive lung adenocarcinoma were 85.2% and 87.4%. The standard uptake values of only two patients determined by 18F-FDG positron emission tomography/computed tomography (PET/CT) were above 2.5. The size, density, shape, and pleural tag of nodules were significant factors that differentiated IA from AIS and MIA. Moreover, the size, shape, margin, pleural tag, vascular cluster, bubble-like sign, and air bronchogram of nodules were significant determinants for mixed ground-glass opacity nodules (all P<0.05).

Conclusion: We analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT and found that the size, density, shape, and pleural tag of SGGNs on HRCT are found to be the determinant factors of IA. In conclusion, detection of anaplastic lymphoma kinase expression and performance of PET/CT scan are not routinely recommended.

Keywords: HRCT; SGGNs; adenocarcinoma; clinical; pathological.

Figure 1

Adenocarcinoma in situ in a 44-year-old woman. Notes: (A) A solitary ground-glass opacity nodule on the superior lobe of left lung was found at the time of her health checkup. She was a nonsmoker, did not have any individual history of cancer and no family history of cancer, and her blood tumor markers were negative. (B) On reexamination by HRCT after 3 months, no obvious change was noted. Hence, she decided to undergo surgical resection. Pathological diagnosis indicated that she had adenocarcinoma in situ. Immunohistochemistry: ALK-V (−), ROS-1 (−). (C) Low-magnification (hematoxylin and eosin, original magnification ×40) photomicrograph demonstrates uniform cuboidal cell proliferation (arrows) involving thickened alveolar walls (lepidic tumor growth). (D) High magnification of (C) (original magnification ×200). Abbreviations: ALK, anaplastic lymphoma kinase; HRCT, high-resolution computed tomography.

Figure 2

Minimally invasive adenocarcinoma in a 55-year-old woman. Notes: (A) A solitary ground-glass opacity nodule on the superior lobe of right lung was observed at the time of her health checkup. She was a nonsmoker, did not have any individual history of cancer and no family history of cancer, and the level of her blood tumor markers CEA was 5.34 ng/mL. She underwent reexamination by HRCT two times and no obvious change was noted (B and C). Afterward, she decided to undergo surgical resection. Pathological diagnosis indicated that she had a minimally invasive adenocarcinoma. Immunohistochemistry: ALK-V (−), ROS-1 (−). (D) Low magnification photomicrographs (hematoxylin and eosin, original magnification ×40) demonstrates lesion consisting of predominantly lepidic tumor growth with several foci (arrows) of invasive acinar components <5 mm in thickness. (E) High magnification of (D) (original magnification ×200). Abbreviations: ALK, anaplastic lymphoma kinase; HRCT, high-resolution computed tomography.

Figure 3

Invasive adenocarcinoma in a 66-year-old man. Notes: (A) A solitary ground-glass opacity nodule on the superior lobe of right lung was observed at the time of his medical examination. He had a smoking history of more than 30 years and no individual history of other cancers; his father had colorectal cancer, and his blood tumor markers were negative. The solid composition of the nodule was found to be increased when he was reexamined by HRCT after 3 months (B). Therefore, he decided to undergo surgical resection. Pathological diagnosis indicated that it was an invasive adenocarcinoma. Immunohistochemistry: ALK-V (−), ROS-1 (−). (C) Low magnification (hematoxylin and eosin, original magnification ×40) shows round-to oval-shaped invasive adenocarcinoma (arrows). (D) High magnification of (C) (original magnification ×200). Abbreviations: ALK, anaplastic lymphoma kinase; HRCT, high-resolution computed tomography.