Tumor size and computed tomography attenuation of pulmonary pure ground-glass nodules are useful for predicting pathological invasiveness.
OBJECTIVE
Pulmonary ground-glass nodules (GGNs) are occasionally diagnosed as invasive adenocarcinomas. This study aimed to evaluate the clinicopathological features of patients with pulmonary GGNs to identify factors predictive of pathological invasion.


METHODS
We retrospectively evaluated 101 pulmonary GGNs resected between July 2006 and November 2013 and pathologically classified them as adenocarcinoma in situ (AIS; n = 47), minimally invasive adenocarcinoma (MIA; n = 30), or invasive adenocarcinoma (I-ADC; n = 24). The age, sex, smoking history, tumor size, and computed tomography (CT) attenuation of the 3 groups were compared. Receiver operating characteristic (ROC) curve analyses were performed to identify factors that could predict the presence of pathologically invasive adenocarcinomas.


RESULTS
Tumor size was significantly larger in the MIA and I-ADC groups than in the AIS group. CT attenuation was significantly greater in the I-ADC group than in the AIS and MIA groups. In ROC curve analyses, the sensitivity and specificity of tumor size (cutoff, 11 mm) were 95.8% and 46.8%, respectively, and those for CT attenuation (cutoff, -680 HU) were 95.8% and 35.1%, respectively; the areas under the curve (AUC) were 0.75 and 0.77, respectively. A combination of tumor size and CT attenuation (cutoffs of 11 mm and -680 HU for tumor size and CT attenuation, respectively) yielded in a sensitivity and specificity of 91.7% and 71.4%, respectively, with an AUC of 0.82.


CONCLUSIONS
Tumor size and CT attenuation were predictive factors of pathological invasiveness for pulmonary GGNs. Use of a combination of tumor size and CT attenuation facilitated more accurate prediction of invasive adenocarcinoma than the use of these factors independently.
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Takashi
T
Eguchi
Department of Pathology, Shinshu University, Matsumoto, Japan.
Akihiko
A
Yoshizawa
Department of Radiology, Shinshu University, Matsumoto, Japan.
Satoshi
S
Kawakami
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Hirotaka
H
Kumeda
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Tetsuya
T
Umesaki
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Hiroyuki
H
Agatsuma
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Takao
T
Sakaizawa
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Yoshiaki
Y
Tominaga
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Masayuki
M
Toishi
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Masahiro
M
Hashizume
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Takayuki
T
Shiina
Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
Kazuo
K
Yoshida
Department of Pathology, Shinshu University, Matsumoto, Japan.
Shiho
S
Asaka
Department of Radiology, Shinshu University, Matsumoto, Japan.
Mina
M
Matsushita
Comprehensive Cancer Center, Shinshu University, Matsumoto, Japan.
Tomonobu
T
Koizumi
D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000368:Aged; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden