Lesiones fibro-oseas

ARTICLE IN PRESS
Current Diagnostic Pathology (2006) 12, 1–10

www.elsevier.com/locate/cdip

MINI-SYMPOSIUM: HEAD AND NECK PATHOLOGY

Maxillofacial fibro-osseous lesions
Paul M. Speighta,Ã, Roman Carlosb
a

Department of Oral Pathology, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield S10 2TA, UK b Centro de Medicina Oral de Guatemala, UniversidadMariano Galvez, 16 Calle 4-53 Zona 10, Guatemala City, Guatemala C.A. 01010, Guatemala

KEYWORDS
Fibro-osseous lesions; Jaws; Fibrous dysplasia; Osseous dysplasias; Ossifying fibroma

Summary Fibro-osseous lesions are a poorly defined group of lesions affecting the jaws and craniofacial bones. All are characterized by the replacement of bone by cellular fibrous tissue containing foci ofmineralization that vary in amount and appearance. Classification and, therefore, diagnosis of these lesions is difficult because there is significant overlap of clinical and histological features. The group includes developmental and reactive or dysplastic lesions as well as neoplasms. Recently a new terminology has emerged that has culminated in the latest WHO classification. The core of this classification isthe concept of a spectrum of clinicopathological entities in which the diagnosis can only be made on the basis of a full consideration of clinical, histological and radiological features. This review will describe the salient features of these lesions in an attempt to provide practical guidance for the surgical pathologist. & 2005 Elsevier Ltd. All rights reserved.

Introduction
Fibro-osseouslesions are a poorly defined group of lesions affecting the jaws and craniofacial bones. All are characterized by the replacement of bone by cellular fibrous tissue containing foci of mineralization that vary in amount and appearance. Classification and, therefore, diagnosis of these lesions is problematical, partly because of a lack of agreement about terminology, but also because of a significantoverlap in histological features. The
ÃCorresponding author. Tel.: +44 114 271 7960;

fax: +44 114 271 7894. E-mail address: p.speight@sheffield.ac.uk (P.M. Speight).

group includes developmental and reactive or dysplastic lesions as well as neoplasms. A number of workers have tried to clarify the classification of these lesions1–7 and although they may not have agreed on an exact terminology, aconcept has emerged which has culminated in the latest WHO classification.8 The core of this classification is the concept of a spectrum of clinicopathological entities in which the diagnosis can only be made on the basis of a full consideration of clinical, histological and radiological features. Although the terminology is still problematic, this review will use this new classification (Table 1) andwill concentrate on the histopathological features that may guide the working surgical pathologist towards a

0968-6053/$ - see front matter & 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.cdip.2005.10.002

ARTICLE IN PRESS
2 diagnosis. It is emphasized again that diagnosis must take account of radiological features and for these the reader is referred to more expert reviews.9,10P.M. Speight, R. Carlos enlargement of the jaws. The monostotic form has an equal gender distribution, but polyostotic lesions are usually found in females. The maxilla and paranasal regions are more frequently affected than the mandible. There are no distinguishing histological features between the three types of fibrous dysplasia. The normal bone is replaced by cellular fibrous tissue composed ofspindled fibroblasts in a moderate amount of collagen. This contains fine branching, curvilinear trabeculae of woven bone with little evidence of osteoblast rimming (Fig. 1), although osteoid seams and osteoclast activity may be seen. A characteristic feature of fibrous dysplasia that may help distinguish it from ossifying fibroma is that the lesional bone merges imperceptibly with adjacent cancellous...