Giant Cell Fibroma of the Tongue: Report of a Rare Entity

Introduction

Giant cell fibroma (GCF), a non-neoplastic process was first described by Weathers and Callihan in 1974.¹ It was categorized as a new entity of fibrous hyperplastic soft tissue lesions. The approximate incidence rate of these lesions is around 2-5%.² Often seen in Caucasians, these fibromas have equal sex predilection. The common site for occurrence is gingiva, followed by tongue, buccal mucosa, lips and floor of mouth.³ They are either sessile or pedunculated asymptomatic swellings with a rough or papillary surface texture. Clinically they resemble any other benign lesions such as fibroma or a squamous papilloma. Histopathological characteristics such as presence of hyperplastic epithelial proliferation and characteristic stellate or star shaped fibroblasts and multinucleated giant cells classify it to be a distinctive entity. Here we report a case of giant cell fibroma occurring in the region of tongue which is relatively a rare location.

Case Report

A 46-year-old female patient reported to the dental clinic with a small swelling on the right side of the surface of the tongue. The swelling was asymptomatic and the duration was around one year. It was slowly increasing in size. She had slight discomfort during eating, swallowing, and cleaning of the tongue. Her past medical, dental history did not reveal any findings of clinical importance. On intraoral examination, a whitish-colored exophytic growth with a papillary surface was observed on the right side of the dorsum of the tongue around 1 cm away from the lateral border and 2.5 cm behind the tip of the tongue (Figure 1). Palpatory findings confirmed a firm pedunculated swelling measuring around 0.5 X 0.5 cm in its largest dimension with a papillary surface. There was no bleeding or any signs of secondary changes on the swelling. A provisional diagnosis of squamous papilloma of the tongue was rendered. With a differential diagnosis of irritation fibroma and pyogenic granuloma, the lesion was excised completely under local anaesthesia. There was minimal bleeding which was controlled by gauze compression and surgical sutures were placed. The obtained biopsy specimen was preserved in 10% formaldehyde solution and sent for histopathological examination. Postoperatively, the lesion healed completely and no recurrence was observed after a follow-up of six months. Macroscopic findings of the excised specimen revealed a firm whitish-colored soft tissue measuring 0.5 X 0.5 cm (Figure 2).

The H & E stained studied sections of the submitted tissue showed normal stratified squamous epithelium with thin elongated rete ridges. The underlying connective tissue showed dense bundles of collagen fibres interspersed with few muscle bundles. The fibroblasts within the connective tissue were typically elongated with few cells showing a binucleate pattern. Stellate-shaped fibroblasts dispersed within the connective tissue were also evident rendering the diagnosis of giant cell fibroma (Figure 3 & 4).

Discussion

Giant cell fibroma, a lesion initially described by Weathers and Callihan in the year 1974 is a nonneoplastic reactive lesion. The word giant cell was used because of the presence of characteristic large mono or multinucleated cells in the fibrous connective tissue stroma.^4,5

It amounts to about 2-5% of all oral fibrous proliferations.⁶ Giant cell fibroma usually occurs in the younger age group;4 but in our case, the lesion was present in an elderly female patient. Clinically they present as a sessile or pedunculated asymptomatic nodular swelling. The size of the lesion is usually less than 1 cm. The surface texture of this entity shows a pebbly or papillary surface often mistaken for a squamous papilloma. According to the previously published reports, the gingiva is the favored site, especially the mandibular gingiva, followed by the maxillary region, tongue, and palate.⁷

The clinical appearance is indistinguishable from any of the other hyperplastic or reactive lesions occurring in the oral cavity. The diagnosis is established based on the histological findings which are unique to this lesion. The presence of characteristic stellate fibroblasts especially in the lamina propria very close to the epithelium is a diagnostic feature. The cytoplasm of these cells is well delineated having large vesicular nuclei with prominent nucleoli. Occasionally the cells can exhibit a dendritic process. Our case demonstrated a hyperplastic stratified squamous epithelium with thinning of rete ridges. The superficial connective tissue showed densely packed collagen fibers with a large number of stellate fibroblasts which is concurrent with the previously published reports.

The hypothesis suggested for the origin of Giant cell fibromas is a hyperplastic response to trauma or a chronic irritation. These responses induce functional change in the fibroblastic cells.⁸ Few reports also suggest that GCF may not be attributed to chronic irritation.⁹ But the presence of few inflammatory cells supports the concept of irritation as an inciting factor. The origin of the giant cells also has been debated. There is evidence of fibroblastic origin for these cells.¹⁰ Ultrastructural studies have shown that these cells contain more microfibrils.¹¹ A myofibroblastic origin for these fibroblasts was also suggested,¹² but due to negative alpha-smooth muscle actin reaction, this concept seemed unlikely.¹³ Positive staining was observed by using vimentin and prolyl 4-hydroxylase markers suggesting a fibroblast lineage. These cells are considered to be of macrophagemonocytic lineage. Regezi et al.,¹⁴ observed that these cells are mesenchymal cells possessing the properties of both macrophage and fibroblast cells. 

The treatment of choice for GCF is surgical excision. There is a low recurrence rate for these lesions.

Giant cell fibromas now have been classified into a separate entity. They are relatively rare in occurrence. Our case is rare in terms of its location, which is tongue, an unusual site for this lesion. Most lesions occur in the gingiva, especially the mandibular gingiva. Recurrence of these lesions is rare. Though these are benign in nature, they need be regularly included in the clinical differential diagnosis as a routine entity. Also, the diagnosis of GCF is based on histology emphasizing the role of biopsy and reporting by eminent oral pathologists.