Prognostic significance of frequent acidophilic nuclear inclusions in adenocarcinoma of the lung with immunohistochemical and ultrastructural studies.
BACKGROUND
Adenocarcinoma of the lung occasionally has acidophilic nuclear inclusions (ANIs). Some studies have reported that the incidence of ANIs was higher in well differentiated tumor types and have suggested that adenocarcinoma patients with ANIs might have a more favorable prognosis; however, to the authors' knowledge, statistically significant prognostic findings were not reported. The objective of the current study was to assess the prognostic significance of ANI in patients with pulmonary adenocarcinoma and, moreover, to characterize ANI immunohistochemically and ultrastructurally.


METHODS
Surgically resected tumor specimens from 147 patients with primary pure adenocarcinoma of the lung were examined. Only obvious ANIs surrounded by a clear halo on hematoxylin and eosin-stained slides were counted; the authors classified cases with > or = 10 ANIs per 10 high-power fields (/10 HPF) as frequent-ANI cases, cases with < 10 ANIs/10 HPF as infrequent-ANI cases, and cases without ANIs as non-ANI cases in the current study.


RESULTS
Nineteen frequent-ANI cases (12.9%) and 16 infrequent-ANI cases (10.9%) were found; the remaining 112 cases (76.2%) were considered to be non-ANI cases. The majority of ANIs immunohistochemically contained surfactant apoprotein and ultrastructurally corresponded to invagination of the inner nuclear membrane, showing a tubular or amorphous configuration. Frequent-ANI patients showed significantly better prognosis than the other two groups on both overall univariate analysis and univariate analysis limited to patients with International Union Against Cancer Stage I disease (P = 0.0096 and P = 0.0095, respectively). However, on the multivariate analysis only disease stage was shown to be a significant prognostic factor and frequent-ANI showed borderline significance (P = 0.0956).


CONCLUSIONS
Frequent ANIs appear to be of limited value in clarifying the prognosis of patients with lung adenocarcinoma.
Aida
S
S
Department of Laboratory Medicine, National Defense Medical College Hospital, Tokorozawa, Saitama, Japan. aidas@me.ndmc.ac.jp
Shimazaki
H
H
Sato
K
K
Sato
M
M
Deguchi
H
H
Ozeki
Y
Y
Tamai
S
S
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000648:ultrastructure; D000368:Aged; D002467:Cell Nucleus / Q000648:ultrastructure*; D004801:Eosine Yellowish-(YS); D005260:Female; D006416:Hematoxylin; D006801:Humans; D007124:Immunoenzyme Techniques; D002479:Inclusion Bodies / Q000648:ultrastructure*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis
D004801:Eosine Yellowish-(YS); D006416:Hematoxylin