[1237] Laryngeal Large Cell Neuroendocrine Carcinoma – A Defining Multi-Institutional Study

JS Lewis, Jr, DC Spence, M Brandwein-Gensler, EL Barnes, SI Chiosea, SK El-Mofty. Washington University School of Medicine, St. Louis, MO; Montefiore Medical Center, Bronx, NY; University of Pittsburgh School of Medicine, Pittsburgh, PA

Background: The WHO classifies laryngeal neuroendocrine carcinomas as typical carcinoid, atypical carcinoid (AC) or small cell carcinoma. The 5 and 10 year survival rates for laryngeal AC are 50% and 34%, respectively, and for small cell carcinoma are far worse. We hypothesized that a distinct laryngeal large cell neuroendocrine carcinoma (LCNEC) can be identified by the WHO pulmonary classification scheme that is associated with a poorer outcome than AC. Our objective was to identify new cases as well as adequately documented reported cases of LCNEC, and to correlate findings with demographic and survival data.
Design: We searched the pathology files of Washington University for the term "neuroendocrine" and anatomic site "larynx". The following histologic criteria were requisite: neuroendocrine morphology, moderate to abundant cytoplasm, high mitotic rate (>10/2mm2), and positive neuroendocrine marker immunohistochemistry (IHC). Small cell carcinoma was excluded. A literature search was also performed for cases of laryngeal neuroendocrine carcinoma, and cases which could be clearly classified as LCNEC were captured. Cases were also solicited from the larger head and neck pathology community.
Results: Six new cases of LCNEC were identified (from 1984 to 2009), along with four cases previously reported in the literature. There were 8 men and two women and 86% were smokers. Eight of 10 patients (80%) presented with lymph node metastases. Nine tumors were supraglottic and one glottic. Histologically, LCNEC was composed of large, pleomorphic tumor cells within the submucosa. Mitotic activity ranged from 48 to 158 per 10 high power fields (average 90). Necrosis ranged from spotty to extensive. Six of 8(75%) developed distant metastases, all to lung or liver. Six of 9 (66%) died of disease, all within three years. Three-year overall survival was 25%. By comparison, the 3 year survival for AC is around 50% (Wenig, Woodruff).
Conclusions: Laryngeal LCNEC is a rare entity and distinct from AC. The sole criterion to distinguish it from AC is mitotic rate, but other histologic features are usually different as well. We recommend that laryngeal tumors fulfilling these criteria not be classified as variants of AC, but rather as a form of high grade (or poorly-differentiated) neuroendocrine carcinoma, as the prognosis is poor.
Category: Head & Neck

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 155, Wednesday Morning


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