Combined large cell neuroendocrine carcinoma and squamous cell carcinoma of the oropharynx: A collision course of tumors

Oropharyngeal Mixed Neuroendocrine-Nonneuroendocrine Neoplasm (MiNEN): A Case Report and Literature Review

Mixed neuroendocrine-nonneuroendocrine (MiNEN) neoplasms in the head and neck are exceptionally rare biphasic tumors with unclear pathogenesis and an aggressive clinical behavior. This is the first reported case of an oropharyngeal MiNEN with the nonneuroendocrine component being an HPV-associated adenocarcinoma. The tumor arose in a 56 year-old male with history of long-term cigarette smoking and was composed of an adenocarcinoma intermixed with a small cell neuroendocrine carcinoma. P16 immunohistochemical stain and HPV16/18 in-situ hybridization were strongly and diffusely expressed in both components.

Primary Oral Mixed Neuroendocrine-Non-neuroendocrine Neoplasm (MiNEN): A Rare Case Report and Review of the Literature

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) are rare tumors recently characterized by the presence of both neuroendocrine and non-neuroendocrine components within the same tumor tissue. Although MiNEN found their place in the WHO classification for various organs, this composite tumor in the head and neck region remains exceptionally rare. We present a case of primary oral MiNEN in a 64-year-old male located on the left side of lower gingiva. Biopsy raised suspicion of neuroendocrine carcinoma (NEC) and the patient underwent partial mandibulectomy. The resected specimen showed two distinct components of NEC and squamous cell carcinoma (SCC) with the confirmation of immunohistochemical markers. There has been no sign of recurrence nor metastasis 6 years after the surgery. In addition, we have conducted a review of published cases with potential relevance to this entity, resulting in five cases. The diverse terminology reinforces the need for a standardized classification system of oral/head and neck MiNENs.