Localized Gingival Enlargement Associated With Alveolar Process Expansion: Peripheral Ossifying Fibroma Coincident With Central Odontogenic Fibroma

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Case Report Localized Gingival Enlargement Associated With Alveolar Process Expansion: Peripheral Ossifying Fibroma Coincident With Central Odontogenic Fibroma ˆ nio Wilson Sallum,* Carlos Eduardo Gomes do Couto-Filho,‡ Cle´verson O. Silva,*† Anto ˆ Alessandro Antonio Costa Pereira,‡ Joa ˜o Adolfo Costa Hanemann,‡ and Dimitris N. Tatakis†

Background: Despite the common occurrence of localized gingival enlargements, which often represent reactive lesions, the temporal and spatial association of such a lesion with a central jaw lesion has not been reported. The purpose of this case report is to present the exceptional combination of a peripheral ossifying fibroma and a central odontogenic fibroma. The differential diagnosis and management of each lesion is reviewed. Methods: A 45-year-old black female presented with a chief complaint of a painless protuberance in the left mandible of 1-year duration. Clinical and radiographic examination revealed a gingival enlargement localized between teeth #21 and #23 and a multilocular radiolucent lesion with radiopaque foci in the same area. Excisional biopsy of the gingival lesion and incisional biopsy of the central lesion were performed, and specimens were submitted for histopathological analysis. Results: Biopsy of the gingival lesion revealed stratified squamous epithelium and highly cellular fibroblastic component presenting central areas of calcification, features consistent with a diagnosis of peripheral ossifying fibroma. The central lesion was characterized by cellular fibrous tissue admixed with rests of odontogenic epithelium and few calcification areas, features consistent with a diagnosis of central odontogenic fibroma/World Health Organization type. Subsequently, the central lesion was enucleated. After 1-year follow-up, no recurrence has been observed. Conclusions: The combination of a rare central lesion with a common gingival lesion may present unique diagnostic and therapeutic challenges. Clinician awareness regarding the possibility of such a combined presentation and its implications will help to ensure optimal treatment outcomes. J Periodontol 2007;78:1354-1359.

* Department of Prosthodontics and Periodontics, School of Dentistry at Piracicaba, University of Campinas, Campinas, SP, Brazil. † Section of Periodontology, College of Dentistry, The Ohio State University, Columbus, OH. ‡ Department of Clinic and Surgery and Department of Biological Science, School of Dentistry, Alfenas Federal University, Alfenas, MG, Brazil.

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KEY WORDS Differential diagnosis; fibroma; fibroma, ossifying; gingiva; odontogenic tumors.

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ocalized gingival enlargements are fairly common and typically represent reactive proliferative lesions, rather than true neoplasms.1-3 Reactive or inflammatory lesions represent >90% of histopathologically analyzed gingival biopsies1,2 and most commonly include diagnoses of pyogenic granuloma, fibrous hyperplasia (fibrous epulis), peripheral ossifying fibroma, and peripheral giant cell granuloma. Typically, such reactive lesions are unifocal and often are associated with local irritants, e.g., plaque, calculus, and poorly fitting or poorly finished restorations.1-3 In rare instances, localized gingival enlargements represent true neoplasms, mostly benign2 (e.g., peripheral odontogenic tumors4), but also malignant, whether primary or metastatic.3,5 Rarely, an apparent gingival enlargement may represent a cyst1 or may be the resulting manifestation of an alveolar bone lesion.3 The coincidental and colocalized appearance of a central jaw lesion, manifesting as cortical expansion, with a true localized gingival enlargement is a unique combination, which, to the best of our knowledge, has not been reported. The purpose of this paper is to report the successfully managed case of an exceptional combination: a peripheral ossifying fibroma, a localized reactive gingival enlargement, and a central odontogenic fibroma, a benign neoplasm central in the jawbones, appearing at the same site and time. The differential diagnosis and management of these lesions also are discussed. CASE REPORT In August 2005, a 45-year-old black female with an unremarkable medical history was referred by a local dentist to the Stomatology Clinic, School of Dentistry,

doi: 10.1902/jop.2007.060477

Silva, Sallum, Couto-Filho, Pereira, Hanemann, Tatakis

J Periodontol • July 2007

Alfenas Federal University, for evaluation of a localized gingival enlargement. The patient’s chief complaint was a painless protuberance in the mandible. She had become aware of the lesion, localized in the area of the mandibular left premolars, over the past year. The patient also noted an increase in the size of the lesion after the extraction of tooth #22, which was performed in October 2004. The extraoral head and neck examination revealed a slight elevation in the area below the left lip commissure but no evidence of lymphadenopathy or other pathoses. The intraoral examination revealed poor oral hygiene and a hard, sessile lump of the same color as the adjacent gingiva located between teeth #21 and #23. The lesion was ;1.5 · 1.0 · 0.6 cm (Fig. 1). The radiographic evaluation of the mandible revealed a multilocular radiolucent lesion with radiopaque foci associated with buccal cortical expansion and displacement of the roots of tooth #21 to the distal and of teeth #23 and #24 to the mesial (Figs. 2 and 3). There also was evidence of distal displacement of the left mental foramen, which was more distant from the midline than the right one and was located under the distally displaced second left premolar; the right mental foramen was located between the first and second right premolars. In addition, the left mental foramen had a triangular appearance (Fig. 2) unlike the more typically shaped (oval) right foramen. There were no radiographic signs associated with the gingival lesion or evidence that the gingival lesion was connected to the central lesion. The differential diagnosis for the gingival lesion included fibroma, peripheral ossifying fibroma, and pyogenic granuloma, and that for the jaw lesion included benign odontogenic neoplasm. An excisional biopsy of the gingival lesion and an incisional biopsy of the central lesion were performed, preceded by full-mouth scaling and root planing. The biopsy specimens were fixed in 10% formalin for routine hematoxylin and eosin (H&E) staining. The excisional biopsy of the gingival lesion included the underlying periosteum and was accompanied by additional root instrumentation of teeth #21 and #23. A thin cortical plate separating the gingival lesion from the central lesion was present, and it was partially removed to provide access for the incisional biopsy of the central lesion. Microscopically, the gingival lesion was characterized by a hyperplastic parakeratotic stratified squamous epithelium and a highly cellular lamina propria with moderate mononuclear inflammatory infiltrate and few multinucleated giant cells amid the fibroblastic component. Central areas of calcification were noted, presenting as round or irregular acellular basophilic structures of variable size resembling cementum-like material (Fig. 4). These histopathological features were consistent with a diagnosis of peripheral ossifying fibroma.

Figure 1. Initial clinical presentation. Note the buccally prominent localized gingival enlargement and the associated tooth migration.

Figure 2. Radiographic image (partial view of panoramic radiograph) at initial presentation showing a radiolucent multilocular lesion and associated tooth migration.

An incisional biopsy of the central lesion was performed to obtain a diagnosis that would dictate the most appropriate therapeutic surgical approach. Once the central lesion was exposed, following removal of the thin cortical plate covering the lesion, a small slice of the lesion was harvested with forceps. The specimen was characterized microscopically by a highly cellular, densely fibrous connective tissue. The collagen fibers were organized in interlaced bundles with cords or islands of odontogenic epithelium and few areas with dentine-like and cementum-like calcifications (Fig. 5). The histopathological features were consistent with a diagnosis of central odontogenic fibroma/World Health Organization (WHO) type. The excisional biopsy was the only treatment performed for the peripheral ossifying fibroma. The area healed properly; 1 year later, there was no evidence of 1355

Peripheral Ossifying and Central Odontogenic Fibromas

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Figure 3.

Figure 5.

Occlusal radiographic view at initial presentation. Buccal cortical expansion and radiopaque foci are evident.

Routine histology of central lesion depicted in Figures 2 and 3 Note the islands of odontogenic epithelium and small areas of calcification within the fiber bundle network. (H&E; original magnification ·250.)

Figure 4.

Figure 6.

Routine histology of gingival lesion depicted in Figure 1. Note the highly cellular fibroblastic component with central areas of calcification. (H&E; original magnification ·100.)

Clinical appearance 1 year after excision of the lesion depicted in Figure 1.

recurrence of the gingival lesion (Fig. 6). One month after the incisional biopsy, the jaw lesion was removed surgically and submitted for histopathological analysis. During the surgery, a well-defined and encapsulated mass was noted and was enucleated. The removed lesion measured 2.5 · 1.5 · 1.5 cm. After enucleation of the lesion, the surgical site was grafted with platelet-rich plasma. The area healed uneventfully, and the histopathological examination of the removed lesion confirmed the initial diagnosis. There was no radiographic evidence of recurrence after 1 year of follow-up (Fig. 7). DISCUSSION The present clinical case concerns the exceptional combination of a relatively common gingival lesion 1356

Figure 7. Radiographic image (partial view of panoramic radiograph) 1 year after enucleation of the lesion depicted in Figures 2 and 3.

J Periodontol • July 2007

(the peripheral ossifying fibroma) with a rare jaw lesion (the central odontogenic fibroma), a combination that is being reported for the first time in the literature. The close temporal and spatial association between a common gingival lesion and a rare central jaw lesion that causes expansion of the alveolar process can become a diagnostic and therapeutic challenge. This is because the combination of the two lesions may render the initial clinical diagnosis difficult, may lead to improper treatment of one or the other lesion, and may complicate the management of the case. From one aspect, the buccal cortical expansion caused by the central lesion may mask the localized gingival enlargement, something that occurred initially in the present case. This may lead to delayed diagnosis and treatment of the peripheral lesion. From the other perspective, focusing on the localized gingival enlargement without consideration for the need to always examine the underlying bone radiographically3 may cause the clinician to miss the central lesion and delay diagnosis and treatment. Even when the diagnosis is not compromised, the presence of two lesions in the same area may complicate the sequence and/or design of the required surgical approaches. The peripheral ossifying fibroma, which occurs exclusively on the gingiva, is a relatively common lesion, accounting for up to 15% of all biopsied gingival lesions.1,6-8 The origins of peripheral ossifying fibroma are not clear; however, it is considered to be derived from the periodontal ligament.9-11 Clinically, the features of the lesion reported here fit well with those described in the literature. It was a sessile lesion12 located in the papillary gingiva area1,9 of a female patient,1,9,13 with the same color as the adjacent gingiva, and