Small cell carcinoma of the lung and large cell neuroendocrine carcinoma interobserver variability.
OBJECTIVE
To test the hypothesis that the published morphological criteria permit reliable segregation of small cell carcinoma of the lung (SCLC) and large cell neuroendocrine carcinoma (LCNEC) cases by determining the interobserver variation.


RESULTS
One hundred and seventy cases of SCLC, LCNEC and cases diagnosed as neuroendocrine lung carcinoma before LCNEC had been established as a diagnostic category were retrieved from the archives of the assessor's institutes. A representative haematoxylin and eosin section from each case was selected for review. Batches of cases were circulated among nine pathologists with a special interest in pulmonary pathology. Participants were asked to classify the cases histologically according to the 2004 World Health Organization (WHO) criteria. The diagnoses were collected and kappa values calculated. Unanimity of diagnosis was achieved for only 20 cases; a majority diagnosis was reached for 115 cases. In 35 cases no consensus diagnosis could be reached. There was striking variability amongst assessors in diagnosing SCLC and LCNEC. The overall level of agreement for all cases included in this study was fair (kappa=0.40).


CONCLUSIONS
Using non-preselected cases, the morphological WHO criteria for diagnosing SCLC and LCNEC leave room for subjective pathological interpretation, which results in imprecise categorization of SCLC and LCNEC cases.
den Bakker
Michael A
MA
Department of Pathology, Erasmus MC, PO Box 2040, 3000 CA, Rotterdam, the Netherlands. m.denbakker@erasmusmc.nl
Willemsen
Sten
S
Grünberg
Katrien
K
Noorduijn
L Arnold
LA
van Oosterhout
Matthijs F M
MF
van Suylen
Robert J
RJ
Timens
Wim
W
Vrugt
Bart
B
Wiersma-van Tilburg
Anne
A
Thunnissen
Frederik B J M
FB
D018287:Carcinoma, Large Cell / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D018278:Carcinoma, Neuroendocrine / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*; D015588:Observer Variation; D055752:Small Cell Lung Carcinoma / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*