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


METHODS
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.


RESULTS
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.
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Kiyoshi
K
Misawa
Department of Regenerative and Infectious Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Hideya
H
Kawasaki
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Rieko
R
Matsuo
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Kenichi
K
Sugiyama
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Daiki
D
Mochizuki
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Shiori
S
Endo
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Atushi
A
Imai
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Yuki
Y
Misawa
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Takashi
T
Yamatodani
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Kunihiro
K
Mizuta
Department of Otolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192 Japan.
Hiroyuki
H
Mineta