Flow cytometric DNA analysis of 20 bronchopulmonary neuroendocrine tumours

Deoxyribonucleic acid (DNA) content of bronchopulmonary neuroendocrine tumours was measured by flow cytometry in order to investigate correlations between ploidy, S-phase fraction (SPF) and two histological classifications (World Health Organization (WHO), Warren and Gould), and clinical staging. A paraffin-embedded technique was used on 20 surgical specimens. Cases comprised (according to the classification of Warren and Gould) 7 carcinoids, 3 well-differentiated neuroendocrine carcinomas (WDNC), 6 intermediate neuroendocrine carcinomas (INC), and 4 small cell neuroendocrine carcinomas (SCNC). DNA aneuploidy was demonstrated in 3 out of 7 of the carcinoids, 3 out of 9 of the WDNCs and INCs, and 2 out of 4 of the SCNCs. A variable SPF was found in each group, except for the SCNCs which showed a constantly high SPF. In our small series, no correlation was noted between high SPF or aneuploidy and metastases. In conclusion, we observed no diagnostic value of malignancy for DNA aneuploidy. The SCNC group appeared to be an homogeneous group according to the SPF compared to the small cell carcinoma (SCC) group of the WHO classification. This and the prognostic incidence of high SPF need to be further studied.