Well-differentiated Neuroendocrine Carcinoma: A Designation Comes of Age

Abstract

In this issue (see page 1053), Lequaglie and co-workers describe a retrospective analysis of their ten-year experience with resected, well-differentiated neuroendocrine carcinoma (WDNC). Their work confirms and extends the observations of others that WDNC is a clinicopathologic entity distinct from other neuroendocrine tumors of the lung, including carcinoid tumor and small cell lung carcinoma (SCLC). 1 Memoli VA Maurer LH. Retrospective histologic classification of long-term survivors with small cell carcinoma.. Lung Cancer. 1986; 2: 56 Google Scholar 2 Warren WH Memoli VA Jordan AG Gould VE. Re-evaluation of pulmonary neoplasms resected as small cell carcinoma: significance of distinguishing between well-differentiated and small cell neuroendocrine carcinomas.. Cancer. 1990; 65: 1003-1010 Crossref PubMed Scopus (34) Google Scholar Utilizing morphologic criteria defined by Gould et al, 3 Gould VE Linnoila RI Memoli VA Warren WH. Neuroendocrine components of the bronchopulmonary tract: hyperplasias, dysplasias and neoplasms.. Lab Invest. 1983; 49: 519-537 PubMed Google Scholar the authors identify 19 cases of resected WDNC. Significantly, while six of the first 12 cases were diagnosed as atypical carcinoids, the remaining six cases had originally been diagnosed as SCLC, thereby reinforcing the observation that some WDNCs are mistaken for SCLC. Refinements in the morphologic diagnosis of WDNC by Warren and co-workers 2 Warren WH Memoli VA Jordan AG Gould VE. Re-evaluation of pulmonary neoplasms resected as small cell carcinoma: significance of distinguishing between well-differentiated and small cell neuroendocrine carcinomas.. Cancer. 1990; 65: 1003-1010 Crossref PubMed Scopus (34) Google Scholar clearly demonstrate that, while the WDNC category encompasses tumors originally diagnosed as atypical carcinoids, it also includes tumors that may be incorrectly diagnosed as SCLC, particularly when diagnostic material is limited to small bronchoscopic biopsy specimens or cytologic preparations. In our experience, 1 Memoli VA Maurer LH. Retrospective histologic classification of long-term survivors with small cell carcinoma.. Lung Cancer. 1986; 2: 56 Google Scholar these cases represent a large majority of long-term survivors with a diagnosis of SCLC. Similar morphologic observations have been made in cytologic studies of bronchial specimens, and criteria have been established for the cytodiagnosis of WDNC. 4 Jordan AG Predmore L Sullivan MM Memoli VA. The cytodiagnosis of well differentiated neuroendocrine carcinoma.. Acta Cytol. 1987; 31: 464-470 PubMed Google Scholar