Genomic profiling of a combined large cell neuroendocrine carcinoma of the submandibular gland

Abstract

A 69-year-old female with no previous medical history presented with a rapidly growing submandibular mass. Fine needle aspiration cytology suggested a small-cell carcinoma and PET-CT showed increased 18-FDG uptake in the submandibular mass as well as in a lung mass. Submandibular resection and selective neck dissection was performed and histopathologic examination revealed a combined large-cell neuroendocrine carcinoma (LCNEC) with a squamous component and without lymph node metastases. Resection of the lung tumor revealed a papillary adenocarcinoma that was morphologically distinctly different from the LCNEC. The patient died of her lung cancer after 19 months without evidence of recurrence of the LCNEC. Genomic profiling of the salivary gland LCNEC revealed a hypodiploid genome predominated by losses of whole chromosomes or chromosome arms involving chromosomes 3p, 4, 7q, 10, 11, 13, 16q and gains of 3q and 16p. In addition, there was a segmental gain of 9p23-p22.3 including the NFIB oncogene. Continued studies of salivary gland LCNEC may provide new knowledge concerning potential diagnostic biomarkers and may ultimately also lead to the identification of new treatment targets for patients with these aggressive carcinomas.