Fibrosarcoma of the gingiva: A rare entity

Abstract

Fibrosarcoma is a rare malignancy of fibroblasts that seldom occurs in the oral cavity. Although rare, fibrosarcoma is an aggressive lesion associated with a poor survival rate. The occurrence of such a highly aggressive lesion on the gingiva is a diagnostic challenge for the clinician. This is because the gingiva is a common site for various inflammatory and nonspecific enlargements, which are commonly benign and the chances to overlook aggressive lesions are high. This case report describes an atypical case of fibrosarcoma of gingiva in a middle-aged individual that mimicked a nonspecific gingival enlargement.

INTRODUCTION

The oral cavity can occasionally be a primary site for connective tissue malignancies. Fibrosarcoma is a malignant tumor of fibroblast, which account for only about 1% of all malignancies affecting humans, out of which only 0.05% occur in the head-and-neck region.[1] Fibrosarcoma in adults is mostly seen in the fifth decade of life with a slight male predilection; the common sites involved are the deep soft tissues of the extremities, trunk, and head-and-neck region. The typical presentation of fibrosarcoma is of a nonspecific soft-tissue mass associated with previous radiation exposure in the area, trauma, foreign body, fibrous dysplasia, Paget’s disease, and chronic osteomyelitis. The histologic picture of fibrosarcoma is that of monomorphic spindle cells with mild-to-moderate degrees of pleomorphism and the tumor cells arranged in a characteristic herringbone pattern. Fibrosarcomas are aggressive lesions capable of multiple local recurrence and lymph node and parenchymal metastasis. The overall survival rate of the lesion is observed to be <70% at 2 years and <55% at 5 years.[2,3]

The incidence of intraoral fibrosarcomas is extremely rare. There had been reports of fibrosarcoma affecting the mandible, maxilla, maxillary sinus, and gingiva.[1-4] The clinical presentation of the lesion varies from lobulated, sessile, painless submucosal masses to aggressive erythematous ulcerated lesions. Irrespective of the clinical appearance, fibrosarcoma destroys the underlying bone and is associated with varying degrees of pain and numbness in the affected area.[2] Gingival fibrosarcoma poses a diagnostic challenge owing to the clinical appearance mimicking pyogenic granuloma and other nonaggressive lesions like peripheral giant cell granuloma or ossifying fibroma. Failure to diagnose fibrosarcoma at the earliest will be perilous for the patient as the lesion is aggressive and associated with a poor survival rate. In this report, we present a rare case of fibrosarcoma occurring on the gingiva in a middle-aged male patient.

CASE REPORT

A 44-year-old male patient presented to the department of periodontics with a chief complaint of enlarged gums in the lower front region for the past 5 months. The patient had bleeding from gums in the same region while tooth brushing. The lesion gradually increased in size to the present dimensions and the patient experienced occasional pain. The patient neither had any relevant medical or family history nor any deleterious oral habits. On examination, the lesion was discrete and pedunculated on the labial side while it was diffuse lingually with respect to 31, 32, 33, and 34. The lesion was erythematous and the size was approximately 1.5 cm × 0.7 cm × 0.4 cm labially and 2 cm × 0.4 cm × 0.5 cm lingually. The extension of the lesion was from the distal side of 31 to the distal of 33 on the labial side and mesial of 41 to the distal of 34 on the lingual side [Figures 1 and 2]. There was grade I mobility with respect to 31, 32, 33, 34, 41, and 42 and pathological migration was evident in relation to 32, 33 [Figure 1]. The submental and submandibular lymph nodes were palpable bilaterally. The radiograph showed horizontal bone loss till the cervical third with respect to lower anterior teeth and loss of lamina dura in relation to 32 and 33 [Figure 3]. An excisional biopsy was planned, and the lesion was completely excised from the buccal and lingual aspects and sent for histopathological examination [Figures 4 and 5]. The decision to do an excisional biopsy was made because of the lesion’s clinical presentation simulating a reactive lesion.

Figure 1.

Picture showing discrete pedunculated gingival enlargment on labial aspect of 31,32,33 and 34

Figure 2.

Diffuse appearance of the lesion on the lingual aspect of 31, 32, 33, and 34

Figure 3.

IOPAR showing horizontal bone loss till cervical third with respect to lower anterior teeth and loss of lamina dura in relation to 32 and 33

Figure 4.

Postoperative view following surgical excision

Figure 5.

Specimen excised from the labial region

The histopathological evaluation under low power (×10) showed a thin layer of atrophic epithelium and highly cellular underlying connective tissue [Figure 6]. The high-power resolution displayed fascicles of spindle-shaped cells arranged in a herringbone pattern. Nuclear and cellular pleomorphism was evident with an increase in mitotic figures [Figure 7]. The histologic picture was characteristic of malignant spindle cell neoplasm. The immunohistochemistry assessment of the specimen showed a positive expression of vimentin, suggesting the mesenchymal origin of the lesion [Figure 8]. The specimen was assessed for the presence of cytokeratin for epithelial origin, smooth muscle cell actin and desmin for muscular origin; S100 for nerve tissue; CD 34 and CD68 for blood cell origin, which all turned out to be negative [Figure 8]. Based on the histopathology and immunochemistry observations, a diagnosis of fibrosarcoma was made. The lesion showed good healing during one week follow up [Figure 9], but the fibrosarcoma being an aggressive lesion the patient had to be referred immediately to an oncology centre for further evaluation and management. The patient was referred to an oncology center for further evaluation and management. Surgical removal of the lesion with en bloc resection of the mandible and elective neck dissection was done at the oncology tertiary care center. The patient was then placed on an adjunctive radiotherapy regimen, and the patient is currently under regular follow-up.

Figure 6.

Low power microscopic view showing a thin layer of atrophic epithelium and highly cellular underlying connective tissue with a herringbone pattern

Figure 7.

High power histologic view showing fascicles of spindle-shaped cells, spindle cells with nuclear pleomorphism, and mitotic figures

Figure 8.

Immunostaining showing positive expression of (a) vimentin at x5 and ( b) at x10 and negative expression of (c) cytokeratin, (d) S100, (e) smooth muscle actin and (f) CD68

Figure 9.

One week postoperative view following excision of the lesion

DISCUSSION

This article reports the case of a malignant tumor that mimicked an inflammatory gingival overgrowth. The differential diagnoses considered were pyogenic granuloma, peripheral giant cell granuloma, peripheral ossifying fibroma, and capillary hemangioma. Pyogenic granuloma presents as a smooth-surfaced pedunculated or sessile mass that shows a tendency to bleed. The peripheral ossifying fibroma is also erythematous and shows a bleeding tendency, and it is commonly seen in the younger age group in the anterior region of the gingiva. Peripheral ossifying fibroma, on the other hand, is negligibly vascular and usually occurs on the gingiva. Capillary hemangioma is a vascular malformation which is red or bluish in color. Hemangioma blanches on digital pressure and can appear pulsatile due to the presence of blood vessels. All these lesions are difficult to differentiate clinically and the diagnosis can only be established by histological evaluation. The lesion in our case report was soft and erythematous and pedunculated in the buccal aspect and sessile in the lingual aspect and showed a tendency to bleed. These observations gave an impression of a nonaggressive lesion and the diagnosis of fibrosarcoma was unsuspected.

Adult fibrosarcoma is a rare but aggressive lesion accounting for 3.6% of soft-tissue sarcomas.[2,4] Fibrosarcomas are capable of local invasion and metastasis, resulting in a poor survival rate. The World Health Organization described fibrosarcoma as a malignant tumor composed of fibroblast with variable collagen and a herringbone arrangement of cells.[5] Fibrosarcoma is inherently a diagnosis of exclusion. Earlier, all soft-tissue sarcomas that mimic fibrosarcomas, such as liposarcoma, rhabdomyosarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor were reported as fibrosarcoma.[6] However with advancements in histopathological analysis and immunohistochemistry, fibrosarcoma can be differentiated from other imitating lesions. Fibrosarcoma histologically shows moderate pleomorphism and the tumors showing a greater degree of pleomorphism are classified as undifferentiated pleomorphic sarcomas. The malignant cells are arranged in a typical herringbone pattern. Other histological findings are the presence of storiform areas, tapered darkly stained nuclei with minimal cytoplasm and variable mitotic activity. Immunohistochemistry shows the expression of vimentin, occasional expression of smooth muscle actin and CD 34.[2]

There had been only a few reports of fibrosarcoma arising from the gingiva. Handler et al. in 1985 documented an unusual case of fibrosarcoma presenting as hyperplastic gingivitis in a young woman. The lesion presented as enlarged, asymptomatic, hyperplastic-appearing gingiva on the labial aspect of the mandibular incisor with supra eruption of incisors. The involved teeth showed grade III mobility and intraoral radiographs exhibited poorly demarcated radiolucency with loss of lamina with respect to lower central and lateral incisors.[7] These findings were similar to the observations in our report. Yamaguchi et al., in their article, reviewed 32 cases of sarcoma in the maxillofacial region over 25 years and observed three cases of fibrosarcomas arising from the mandibular soft tissue. After surgical and adjunctive radio and chemotherapy, these three patients showed no recurrence or metastasis for 5 years.[8] Akhtar et al. described a case of fibrosarcoma in a young female presenting as gingival enlargement in the mandibular molar region, which caused difficulty in chewing. The patient, after surgical excision and adjunctive chemotherapy, reported no signs of recurrence for 2 years.[3] A recent case report documented fibrosarcoma presenting as a progressive, sessile gingival growth on the labial surface of mandibular incisors. The teeth proximal to the lesion showed grade II mobility and horizontal bone loss. The authors of this paper suspected the lesion as pyogenic granuloma with localized periodontitis. The incisional biopsy and analysis of the lesion showed it as fibrous hyperplasia, the authors then excised the mass in toto with healthy margins and the covered denuded bone surface by free gingival graft. The excised lesion was later diagnosed as fibrosarcoma on histologic and immune-histochemical analysis.[9]

In this case report, fibrosarcoma was an unexpected diagnosis because of the clinical presentation and absence of any relevant history. The histopathologic analysis proved to be the key to the diagnosis of the lesion. Early diagnosis of any sarcoma is important for improving the patient’s chances of survival. Fibrosarcomas are aggressive lesions; 80% of lesions are reported to be high-grade tumors and 25% of low-grade tumors progress to high grade over time. Surgical excision is the treatment of choice for sarcomas. Wide resection with clear margins is essential for patient survival. The adjunctive usage of radiation and chemotherapy is debatable. The combined therapy of surgery and radiotherapy is found to reduce recurrence but not overall survival.[10]

CONCLUSION

Intraoral lesions can present in an unusual manner making the diagnosis challenging. Aggressive soft-tissue tumors should be considered a differential diagnosis for gingival overgrowth. It is judicious to send all growths excised from the oral cavity for histopathological analysis regardless of the clinical nature of the lesion because an early and accurate diagnosis is critical to ensure patients’ survival.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.