ABSTRACT 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  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.
Cite this paper
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.
 Tomich, C.D. and Moll, M.C. (1976) Palisaded, encapsulated neuroma of the lip. Journal of Oral Surgery, 34, 265-268.
 Reed, R.J., Fine, R.M. and Meltze, H.D. (1972) Palisaded, encapsulated neuromas of the skin. Archives of Dermatology, 106, 865-870.
 Koutlas, I.G. and Scheithauer, B.W. (2010) Palisaded encapsulated (“solitary circumscribe”) neuroma of the oral cavity: A review of 55 cases. Head and Neck Pathology, 4, 15-26. doi:10.1007/s12105-010-0162-x
 Magnusson, B. (1996) Palisaded encapsulated neuroma (solitary circumscribed neuroma) of the oral mucosa. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology, 82, 302-304.
 Mayorga, M., Acebo, E. and Val-Bernal, J. (1998) Palisaded encapsulated neuroma of the nasal fossa. Otolaryngology—Head and Neck Surgery, 119, 141-143.
 Navarro, M., Vilata, J., Requena, C. and Aliaga, A. (2000) Palisaded encapsulated neuroma (solitary circumscribed neuroma) of the glans penis. British Journal of Dermatology, 142, 1061-1062.
 Chauvin, P.J., Wysocki, G.P., Daley, T.D. and Pringle, G.A. (1992) Palisaded encapsulated neuroma of oral mucosa. Oral Surgery, Oral Medicine, Oral Pathology, 73, 71-74.
 Chrysomali, E., Papanicolaou, S.I., Dekker, N.P. and Regezi, J.A. (1997) Benign neural tumors of the oral cavity: A comparative immunohistochemical study. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology, 84, 381-390.
 Dover, J.S., From, L. and Lewis, A. (1989) Palisaded encapsulated neuromas: A clinicopathologic study. Archives of Dermatology, 125, 386-389.
 Fletcher, C.D.M. (1989) Solitary circumscribed neuroma of the skin (so-called palisaded, encapsulated neuroma): A clinicopathologic and immunohistochemical study. American Journal of Surgical Pathology, 13, 574-580.
 Scheithauer, B.W., Woodruff, J.M. and Erlandson, R.A. (1997) Reactive lesions, inflammatory and infectious lesions simulating tumors of the nerve, hyperplastic lesions, hamartoma and choristoma, schwannoma, neurofibroma and miscellaneous benign neurogenic tumors. In: Tumors of the Peripheral Nerve System, Armed Forces Institute of Pathology, Washington DC, 25-282.
 Argenyi, Z. (1990) Immunohistochemical characterization of palisaded, encapsulated neuroma. Journal of Cutaneous Pathology, 17, 329-335.
 Zelgar, B., Stainer, H., Kutner, H., Rütten, A. and Zelger, B. (1997) Verocay body-prominent cutaneous schwannoma. American Journal of Dermatopathology, 19, 242- 249. doi:10.1097/00000372-199706000-00007
 Dover, J., From, L. and Lewis, A. (1989) Palisaded encapsulated neuromas: A clinicopathologic study. Archives of Dermatology, 125, 386-389.
 Albrecht, S., Kahn, H.J. and From, L. (1989) Palisaded encapsulated neuroma: An immunohistochemical study. Modern Pathology, 2, 403-406.