Human papillomavirus-associated small cell carcinoma/neuroendocrine carcinoma of the oropharynx: a report of two cases

INTRODUCTION Small cell carcinoma/neuroendocrine carcinoma (SCNEC) of the oropharynx is uncommon. Two cases of SCNEC in an 81-year-old woman and in a 54-year-old man are presented here. CASE DESCRIPTION We have documented two cases of SCNEC arising in the oropharynx with evidence of high-risk human papillomavirus (HPV) infection. Histologically, both cases were classified as poorly differentiated SCNEC with high nuclear-to-cytoplasmic ratios and nuclear molding. Observations using a transmission electron microscope revealed membrane-bound neuroendocrine granules in some tumor cells. Both tumors expressed high levels of p16, a surrogate marker for high-risk HPV infection. HPV infection was confirmed in both cases using HPV polymerase chain reaction analysis; HPV subtype 16 was identified in one case and HPV subtype 18 in the other. DISCUSSION AND EVALUATION SCNEC of the oropharynx is a rare and novel HPV-associated disease with neuroendocrine granules and aggressive clinical behavior. CONCLUSIONS Herein, we present two cases of SCNEC, focusing on its histologic features and treatment modalities. More studies are required to elucidate the pathophysiology of HPV-associated SCNEC in different organ systems.