Author(s)

Kayo Kuyama, Hirotaka Oomine, Yan Sun, Masanobu Wakami, Hirotsugu Yamamoto

Department of Crown and Bridge Prosthodontics, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
Department of Diagnostic Pathology, Hospital of Nihon University School of Dentistry at Matsudo, Matsudo, Japan.
Department of Maxillo-Facial Orthodontics, Nihon University School of Dentistry at Matsudo.
Department of Oral Pathology, Nihon University School of Dentistry at Matsudo, Matsudo, Japan.

Palisaded encapsulated neuroma (PEN; solitary circumscribed neuroma) is a benign and hyperplastic lesion consisting of Schwann cells. PEN of the lower lip was reported by Tomich and Moll [1] 35 years ago. However, the accumulation of the information about PEN which occurred in the oral mucosa was not enough. This article describes a case of a PEN on the upper lip of a 41-year-old woman. The lesion with 0.7 cm diameter was performed excisional biopsy. Histologically, the tumor was almost circumscribed by thin fibrous capsule, and consisted of diffusely and dense proliferation of the spindle shape cells arranged in interlacing fascicles. Focal suggestions of nuclear pal-isaded growth were indicated within the tumor. Immunohistochemicallly, the fascicles of tumor cells were positive for S-100 protein, and vimentin and negative for α-actin and GFAP. A few numbers of axons were demonstrated by anti-neurofilament antibody in this lesion. Therefore, the definitive diagnosis was PEN.

Palisaded Encapsulated Neuroma; Solitary Circumscribed Neuroma; Immunohistochemistry

Kuyama, K. , Oomine, H. , Sun, Y. , Wakami, M. and Yamamoto, H. (2012) Palisaded encapsulated neuroma of the upper lip. Open Journal of Stomatology, 2, 228-233. doi: 10.4236/ojst.2012.23040.