原文題目

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口腔病理科 On-Line KMU Student Bulletin

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原文題目(出處)： Unusual intramandibular plexiform schwannoma. Oral Surg 2011;4:51-5.

原文作者姓名： Bavle RM, Thambiah LJ, Nanda Kumar H, Srinath N, Paremala K, Sudhakara M

通訊作者學校： Krishnadevaraya College of Dental Sciences and Hospital, Department of Oral Pathology, Hunasamaranahalli, (via) Yelahanka Bangalore, Bangalore, Karnataka, India

報告者姓名(組別)：蔡豐駿 Intern I 組

報告日期： 2011/4/11

內文：

Introduction

 Neoplasms of peripheral nerve in the head and neck region are of common occurrence-- oral and para-oral tissues is uncommon--rarely occur centrally within the jaws

 Schwannoma --age group ranging from 10 to 40 years-- discrete, freely movable, smooth-surfaced-- painless soft tissue swelling

 Intraosseous schwannomas--1% of all bone tumours in the entire body

 Classical schwannoma is an encapsulated neoplasm-- Antoni type A and Antoni type B

 Antoni A tissue—cellular--monomorphic spindle-shaped Schwann cells--poorly defined eosinophilic cytoplasm--basophilic nucleus--nuclear palisading--parallel arrays of such palisades with intervening eosinophilic cell cytoplasm--Verocay bodies

 Antoni B--cytoplasm is inconspicuous--nuclei are suspended in copious myxoid

 Schwannoma--cellular, epitheloid, melanotic and ancient--plexiform schwannoma

 Plexiform schwannoma--extremely rare and unique--superficial soft tissues in the head and neck region

Case report

 A 54-year-old male patient-- reported to the Krishnadevaraya College of Dental Sciences and Hospital, Bangalore, India--chief complaint of swelling in the left cheek region for the past 6 months

 Extraoral examination—asymmetry--left side of the face in the preauricular and mandibular area--swelling extended inferio-superiorly from the lower border of the mandible to the ala-tragal line--anteroposteriorly from 2.0 cm posterior to the angle of the mouth to the angle of the mandible.

 The swelling measured 3.0 x 3.0 cm in dimension--well-defined, hard, non-tender, with normal overlying skin

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 Intraoral examination--a polypoid mass--1.0 x 2.0 cm in relation to the left retromolar area

 The mass--well defined, soft and non-tender, obliterating the buccal sulcus--Overlying mucosa--large central area of yellowish gray mucinous covering

 The orthopantamograph--multilocular radiolucency with faint trabeculae, suggesting loculation--smooth and distinct borders extending from the region of 36 to the left ramus of the mandible--lower border of the mandible was intact--root resorption of 37

Pathology

Macroscopic findings

 The lesional tissue measured 5.5 x 4.5 cm in dimension--soft in consistency--multiple nodules--tenacious fibrous intervening tissue

Microscopic features

The haematoxylin- and eosin-stained sections showed clearly segregated multiple nodules in lower magnification(x 40)

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 These nodules (x100 and x400) --cellular stroma at many areas--spindle in shape--eosinophilic cytoplasm--basophilic oval nucleus--palisading

 Parallel arrays of such palisades--intervening eosinophilic cell cytoplasm – Verocay bodies – were evident, depicting Antoni type A tissue.

 These densely cellular areas--alternating with less cellular, loose, oedematous areas--numerous small blood vessels exhibiting perivascular hyalinization--collagenisation representing Antoni type B areas

 S-100 immunostaining--strong positivity in the nerve fascicles--Antoni type A and Antoni type B areas of the section--capsular and the intervening areas showed negative staining

Discussion

 Plexiform schwannoma--first described in 1978--superficial soft tissues, particularly of the head and neck region--superficially situated peripheral

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nerve--4.3% of all schwannomas--23% of schwannomas of head and neck soft tissues, with only 28 reported cases--a true central tumour with multinodular growth, seems to be among the first reported cases.

 Microscopically plexiform schwannoma--(x40) showed multinodularity in almost all the areas--nodules were covered by fibrous and cellular connective tissue capsule.

 cellular arrangement with palisading nuclei--Verocay bodies (Antoni type A tissue)-- occasional loose texture areas--cells having multiple processes--capillaries showing perivascular hyalinisation (Antoni type B tissue)

 strongly positive immunohistochemical staining with S-100 in the nodules--nature of the lesion to be of neural tissue--S-100 was completely negative in the superficial capsular areas--intervening and fibrous in nature.

 Plexiform schwannoma--benign tumour--no malignant potential--recur when incompletely excised.

 no evidence of increased cellularity or cellular changes like epitheloid-like cells linked with malignant changes--No nuclear pleomorphism and mitotic figures were seen--absence of features of malignancy at cellular or tissue level.

 Author report a case of intraosseous plexiform schwannoma--rare and unique variant of Schwann cell tumour at a central location in the mandible and can be the first of its kind

題號題目

1 Which one is not the clinical feature of schwannoma?

(A) Usually asyptomatic

(B) Range from a few millimeters to several centimeters in size (C) Tongue is the most common location

(D) Intraosseous examples are most common in the maxilla 答案(D ) 出處：口病課本 p.526-527

題號題目

2 Which one is not the histopathologic feature of schwannoma?

(A) Verocay bodies (B) Negative for S-100

(C) Two microscopic patterns: Antoni type A and Antoni type B (D) Have spindle-shaped cells

答案(B) 出處：口病課本 p.527