Quandary in Diagnosing Peripheral Ossifying Fibroma and Pyogenic Granuloma: A Case Report with Mini Review

Abstract

The soft tissues of the oral cavity are constantly subjected to microtrauma due to various factors. The gingiva in particular reacts to these beyond a point resulting in reactive hyperplastic lesions. Amongst these, the pyogenic granuloma and the peripheral ossifying fibroma are the most common clinical entities. Since they have a similar clinical presentation but diverse histomorphologic illustrations, it was advocated that there exists an interrelation between these two reactive fibrous overgrowths. Hence, this paper is intended to abolish the quandary in diagnosing peripheral ossifying fibroma and pyogenic granuloma.

Introduction

Soft tissue lesions of the oral cavity generally pose a diagnostic challenge even to an experienced operator. They epitomize a disparity of normal anatomy, congenital anomalies, inflammatory lesion, cystic lesion or neoplasm [1]. The gingiva of the oral cavity in particular is relentlessly subjected to mild irritation due to constant masticatory forces, occasional entrapment of food debris, poor restorations and prosthesis or plaque and calculus [2]. At a point when the gingiva starts reacting to these irritants, it results in a reactive hyperplastic growth in a localized area. These include the peripheral giant cell granuloma, pyogenic granuloma, fibrous hyperplasia, peripheral ossifying fibroma, etc [2].

Peripheral ossifying fibroma (POF) is a focal reactive overgrowth, whereas pyogenic granuloma (PG) is an inflammatory hyperplasia with similar clinical presentation but diverse histomorphologic illustrations [3]. Few studies show that POF occasionally may develop initially as a PG that undergoes subsequent fibrous maturation and calcification [4]. Hence, these two lesions are considered to be representing the progressive stages of the same spectrum of pathosis. The literature is scanty with reports published describing the interrelationship between these two lesions. Hence, this case report depicts the interrelation between these two reactive fibrous overgrowths having different histomorphologic representations.

Case Report

A 16-year-old girl reported with the chief complaint of soft tissue growth in the front region of her upper jaw. She gives a history of painless swelling since 2 months which started as a peanut size and grew to the present size. There was no history of trauma and no history of previous swelling in the oral cavity. Past medical and family history was non-contributory. Intraoral examination revealed a solitary sessile growth noticed on the buccal aspect of the gingiva at maxillary right permanent canine and first premolar region. The lesion was pink in color with a smooth surface. No surface ulceration was noted. It was extending from the attached gingiva onto the lateral surfaces of the canine and first premolars toward the occlusal surface (Fig. 1). The lesion was measuring 1.5 cm superoinferiorly and 2 cm mesiodistally. On palpation, the lesion was painless and firm in consistency with bleeding on probing. Radiograph revealed noosseous changes, and the canine and first premolars were unaffected by the lesion.

Fig. 1.

Preoperative view of the lesion

Based on the clinical and radiographic findings, a provisional diagnosis of pyogenic granuloma was made. Patient consent was obtained, and following routine hematological examinations, patient was subjected to excisional biopsy of the growth (Fig. 2). A thorough curettage of the adjacent periodontal ligament and periosteum was carried out to prevent recurrence.

Fig. 2.

Excised specimen

Histomorphological examination revealed a keratinized stratified squamous epithelium overlying a cellular connective tissue stroma which had a delicate to dense collagen fiber bundles, moderate infiltration with inflammatory cells and few blood vessels. Connective tissue showed areas of new bone formation in trabecular pattern. The trabeculae revealed osteoblastic rimming, osteocytes in the lacunae and osteoid suggestive of peripheral ossifying fibroma (Fig. 3). The follow-up of the case showed normal healing of the area. Healing was uneventful, and 1-year follow-up revealed no signs of any recurrence.

Fig. 3.

a Histopathological view of the lesion in 4× view. b Histopathological view of the lesion in 10× view

Discussion

PG manifests as a result of a known irritant in the form of calculus or foreign material within the gingival crevice that causes exuberant proliferation of connective tissue [5]. Studies show that it is frequently encountered in females in their second decade of life due to the augmented levels of estrogen and progesterone in circulation [6]. On the contrary, it is to be noted that a recent study revealed that this lesion is found in males and females with no specific sex predilection. Recurrent trauma occurring during tooth brushing or function in addition to the presence of a local irritant leads to the release of various endogenous and angiogenic factors contributing to the increased vascularity of the lesion [5, 7].

PG may present as an solitary, smooth or exophytic, sessile or pedunculated growth covered with erythematous papules [5]. It affects the marginal gingiva more than the alveolar part predominantly in the anterior maxilla [8]. The size varies from a few millimeters to several centimeters, and it is usually a slow-growing, asymptomatic, painless growth [5, 9].

This lesion can be managed surgically with the aid of scalpel, Nd: YAG laser, carbon dioxide laser, flash lamp pulse dye laser, cryosurgery, electrodessication in addition to sodium tetradecyl sulfate sclerotherapy and use of intra lesional steroids [10, 11]. Incomplete excision and failure to remove the etiologic factors or frequent trauma result in recurrence of the lesion [5]. Recurrence rate of 16% followed surgical treatment of PG [12].

POF also presents as a solitary, slow-growing, pedunculated or sessile, nodular mass [13]. The surface mucosa can be smooth or ulcerated and pink to red in color. It exclusively affects the gingiva and comprises about 9% of all gingival growths [14]. Migration of teeth with interdental bone destruction and delay in the eruption of permanent teeth are occasionally seen [15, 16]. It is a reactive lesion originating from the periodontal ligament as a result of irritation from dental calculus, plaque, orthodontic appliances or ill-fitting restorations [17]. It tends to occur more in the second decade of life with female predilection [18]. Hormonal influences may play a role, given the higher incidence of POF among females, increasing occurrence in the second decade and declining incidence after the third decade [18]. Management of the lesion includes complete removal of the lesion down to bone involving also the adjacent periosteum and the periodontal ligament [19]. A recent study showed a recurrence rate of 30.4% followed surgical treatment of POF [13].

POF denotes a distinct clinical entity rather than a conventional form of pyogenic granuloma [18]. In the early stages, POF exhibits as ulcerated nodules with little calcification, permitting easy misdiagnosis as a pyogenic granuloma [20]. PG generally presents as a small lesion with a tendency to bleed. It may or may not show calcifications but does not cause tooth displacement and resorption of alveolar bone [21]. POF lacks the purple or blue discoloration commonly associated with peripheral giant cell granuloma and radiographically shows flecks of calcification.

The critical reason for the confusion that prevails over diagnosis of PG and POF is that immature lesions are soft and tend to bleed easily, whereas older lesions become firm and fibrotic. Hence, the immature lesions can easily be confused with pyogenic granuloma [2, 22]. However, chronic irritation not only to the gingiva but also to the periosteal and periodontal membrane causes metaplasia of the connective tissue which initiates the formation of bone and dystrophic calcification in POF which is not present in PG [2, 23].

Clinically, both PG and POF present as a solitary, slow-growing, pedunculated or sessile, growth on the attached gingiva predominantly in the upper anterior region during the second decade of life [5, 8, 13, 14]. Microscopically, both PG and POF show granulation tissue which is covered by atrophic/hyperplastic epithelium with the presence of numerous endothelium-lined vascular spaces and proliferation of fibroblasts and budding endothelial cells and presence of mixed inflammatory cell infiltration [24]. However, microscopic picture of POF in addition to the above reveals calcifications which resembled trabecular bone [25]. The reason for the presence of calcified structures in POF may be its tissue of origin either from fibrous metaplasia or from osteogenic differentiation of cells, in which inflammation can play a role [26].

A recent study analyzed the expression of osteopontin in normal gingival tissue and different types of focal reactive proliferations of gingiva [25]. Osteopontin is a non-collagenous protein which is a highly phosphorylated sialoprotein and has high calcium-binding potential. OPN is produced by osteoblasts osteocytes and osteoclasts [27, 28]. It contains several serine phosphorylated sites and stretching of negatively charged aspartic acid residues responsible for the attraction of calcium and also influences mineralization [25].

The epithelium present both in normal oral mucosa and in focal reactive proliferation is totally negative for OPN expression [25, 26]. There is an osteoblastic differentiation of stromal cells in focal reactive proliferations of gingiva. The pyogenic granuloma showed OPN expression in the stromal cells and extracellular matrix in few cases, which favors the concept that pyogenic granuloma may mature into POF. However, POF showed OPN expression in stromal cells, extracellular matrix, and in areas of ossification in all the cases [25, 26]. The study also reveals that majority of POF arises from the periodontal ligament cells. Finally, it can be concluded that a mature PF following repeated trauma can change into a POF [29, 30].

Conclusion

It is a well-known fact that a plethora of lesions manifest in the oral cavity with identical clinical outcomes and virtually similar histological illustrations. In particular, the reactive lesions of the soft tissue pose such a quandary even to an experienced operator. POF and PG are mostly misdiagnosed and at times considered to be representing the progressive stages of the same spectrum of pathosis. Hence, a thorough understanding is essential to abolish the quandary in diagnosing peripheral ossifying fibroma and pyogenic granuloma.

Funding

Self-funded.

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.

Informed Consent

Patient consents are taken.

Ethical Approval

Institutional ethical clearance is taken.