Comparison of thin-section CT and pathological findings in small solid-density type pulmonary adenocarcinoma: prognostic factors from CT findings.
OBJECTIVE
We divided pulmonary adenocarcinoma of ≤ 20 mm into air-containing and solid-density types based on a percentage reduction of the maximum tumor diameter in the mediastinal window image compared to the area in the lung window image on thin-section (TS) CT of ≥ 50% (air-containing type) and <50% (solid-density type). No relapse occurred in patients with air-containing type. The prognosis of solid-density type may be poor even when the tumor size is 20mm or smaller. We investigated whether CT findings for these tumors could serve as prognostic factors.


METHODS
The subjects were 105 patients with solid-density type pulmonary adenocarcinoma that was identified on TSCT and found to have a diameter of 20mm or smaller after surgical resection during the period from April 1997 to November 2004. Notches, air bronchogram, pleural retraction, spiculation, venous involvement, and ground glass opacity were examined on TSCT, and their associations with pathological findings (i.e., pleural invasion, lymphatic permeation, vascular invasion, lymph node metastasis, and Noguchi's classification) and relapse were investigated using chi-square test and Cox proportional hazards model.


RESULTS
The incidence of relapse was significantly higher in cases with notches. The incidence of notches increased with tumor growth and notches were frequent in Noguchi type D tumors, reflecting poorly differentiated adenocarcinoma. Lymphatic permeation and type D cases were independent factors associated with a poor prognosis using Cox proportional hazards model.


CONCLUSIONS
TSCT findings may be useful for prediction of the prognosis of solid-density type pulmonary adenocarcinoma.
Division of Respiratory Diseases, Department of Internal Medicine, Federation of National Public Service Personnel Mutual Aid Associations, Hirakata Kohsai Hospital, Japan. mizukiikehara@aol.com
Mizuki
M
Ikehara
Haruhiro
H
Saito
Tetsuro
T
Kondo
Shuji
S
Murakami
Hiroyuki
H
Ito
Masahiro
M
Tsuboi
Fumihiro
F
Oshita
Kazumasa
K
Noda
Haruhiko
H
Nakayama
Tomoyuki
T
Yokose
Yoichi
Y
Kameda
Kouzo
K
Yamada
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000401:mortality*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis* / Q000401:mortality*; D016019:Survival Analysis; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*