Appendiceal Goblet Cell Carcinoid: Common Errors in Staging and Clinical Interpretation with a Proposal for an Improved Terminology

Publication date: Available online 24 May 2017
Source:Human Pathology
Author(s): Kwun Wah Wen, Gillian Hale, Nafis Shafizadeh, Mojgan Hosseini, Anne Huang, Sanjay Kakar
Goblet cell carcinoid (GCC) is staged and treated as adenocarcinoma (AC) and not as neuroendocrine tumor (NET) or neuroendocrine carcinoma. The term 'carcinoid' may lead to incorrect interpretation as NET. To explore pitfalls in staging and clinical interpretation of GCC and mixed GCC-AC, and propose strategies to avoid common errors. Diagnostic terminology, staging and clinical interpretation were evaluated in 58 cases (27 GCC, 31 mixed GCC-AC). Opinions were collected from 23 pathologists using a survey. Clinical notes were reviewed to assess the interpretation of pathology diagnoses by oncologists. NET staging was incorrectly used for 25% GCC and 5% mixed GCC-AC. In the survey, 43% of pathologists incorrectly indicated that NET staging is applicable to GCC and 43% incorrectly responded that Ki-67 proliferation index is necessary for GCC grading. Two cases each of GCC and mixed GCC-AC were incorrectly interpreted as neuroendocrine neoplasms by oncologists, and platinum-based therapy was considered for 2 GCC-AC cases due to the mistaken impression of neuroendocrine carcinoma created by use of the World Health Organization (WHO) 2010 term 'mixed adenoneuroendocrine carcinoma' (MANEC). The term 'carcinoid' in GCC and use of MANEC for mixed GCC-AC leads to errors in staging and treatment. We propose that 'goblet cell carcinoid' should be changed to 'goblet cell carcinoma', while GCC with AC should be referred to as 'mixed GCC-AC' with a comment about the proportion of each component and the histologic subtype of AC. This terminology will facilitate appropriate staging and clinical management, and avoid errors in interpretation.



http://ift.tt/2rzk3LJ