Plexiform Schwannoma: A Report of Two Unusual Cases, and a Review of the Literature

Shabnum Ali,Philip Stenhouse,Leandros Vassiliou

doi:10.4236/ojst.2014.44026

Abstract

Plexiform schwannoma is a benign tumour arising from the sheath of myelinated nerve fibres that may occur in any part of the body. It is very rare in the head and neck region and poses diagnostic challenges. Here we present two unusual cases. The first is about a fifteen-year-old boy with a large plexiform schwannoma in the right retro maxillary region, extending up to but not invading the orbit. Initial cytology reported it as a pleomorphic adenoma, but histological findings after excision confirmed it to be a benign plexiform schwannoma. A zygomatic osteotomy was required to excise the tumour in its entirety. The second reported case is about solitary lesion on the tongue of a 46-year-old Chinese man, clinically mimicking a mucocoele. This case report highlights the diagnostic challenges posed by plexiform schwannoma, and the role of imaging and cytopathology, as well as the importance of definitive histopathological analysis. It also describes the surgical management of these lesions, and provides a review of the literature, in particular of cases occurring in the head and neck region.

Highlights

IntroductionHow to cite this paper: Ali, S., Vassiliou, L. and Stenhouse, P. (2014) Plexiform Schwannoma: A Report of Two Unusual Cases, and a Review of the Literature
Schwannoma is a benign tumour arising from the sheath of myelinated nerve fibres that may occur in any part ofHow to cite this paper: Ali, S., Vassiliou, L. and Stenhouse, P. (2014) Plexiform Schwannoma: A Report of Two Unusual Cases, and a Review of the Literature
Plexiform schwannoma is a rare variant of schwannoma that accounts for only 5% of all schwannomas, and typically shows a plexiform or multinodular growth pattern [2]

Summary

Introduction

How to cite this paper: Ali, S., Vassiliou, L. and Stenhouse, P. (2014) Plexiform Schwannoma: A Report of Two Unusual Cases, and a Review of the Literature. Plexiform schwannoma is a rare variant of schwannoma that accounts for only 5% of all schwannomas, and typically shows a plexiform or multinodular growth pattern [2] It was first described by Harkin and Reed in 1978 [3], and very few cases had since been reported. Plexiform schwannoma usually develops in the dermis or subcutaneous tissue, and it is uncommon for the schwannoma to develop in deep seated nerves It is a benign, sporadic neoplasm and is characterized histologically by small, round lesional cells surrounding collagenous cores forming rosette-like structures [4]. Sporadic neoplasm and is characterized histologically by small, round lesional cells surrounding collagenous cores forming rosette-like structures [4] This rare benign tumour is worthy of recognition because it can be misdiagnosed as plexiform neurofibroma. In contrast, not necessarily associated with von Recklinghausen disease [neurofibromatosis type I] and malignant transformation has never been observed [5]

Case Report 1

Case Report 2

Findings

Discussion