Gingival squamous cell carcinoma mimicking as a desquamative lesion.

Oral squamous cell carcinoma (SCC) is the most frequently encountered neoplasm in the oral cavity, which accounts for more than 90% of all cancers. Except for carcinoma of the lip vermilion, the most common sites of oral SCC are the tongue and floor of mouth, followed at a lower frequency by the soft palate, gingiva, and buccal mucosa. Clinically, it may be misdiagnosed because of its variable appearances. This case report presents a case of well-differentiated SCC of gingiva. A 48-year-old male patient reported to the Department of Periodontology, School of Dental Sciences, Karad, with a 1-year history of burning sensation and painful lesion on the gingiva from 35 to 37 (mandibular) regions. On clinical examination, desquamated gingival lesion was seen with no purulent exudation. Clinical characteristics and differential diagnosis indicated the lesion for an excisional biopsy. Histopathological examination confirmed the lesion to be a well-differentiated SCC. The patient was referred for the treatment consisting of surgical excision of the lesion. Since an early diagnosis and treatment was possible in this case, it resulted in a good prognosis. In these instances, dentist plays an important role in early detection of gingival SCC.

INTRODUCTION

Carcinoma of the gingiva constitutes an extremely important group of neoplasms and accounts for 6.3% of all the oral carcinomas between the ages of 36 and 65 years and up to 91.4% in patients older than 66 years.[12] Oral cancer continuous to be a major health concern of which squamous cell carcinoma (SCC) is the most frequently associated neoplasm of the oral cavity. It has been reported[3] that approximately 10% of all malignant tumors of the oral cavity occur on the gingiva, and that tumors arise more commonly in edentulous areas, although they may develop at sites where teeth are present. It is generally agreed that carcinomas of the mandibular gingiva are more common than those of the maxillary gingiva, and 60% of those are located posterior to the premolars,[3] commonly occurring in females than males.

The etiology of gingival SCC appears to be no more specific or defined, but predisposing factors such as smoking associated with heavy alcohol use are well known.[4] The similarity of this lesion with inflammatory conditions affecting the periodontium has frequently led to delay in diagnosis or even misdiagnosis. Hence, it is of paramount importance that the lesion should be diagnosed early to initiate treatment, prevent metastasis as it is well documented that this lesion frequently metastasizes, especially in submaxillary and cervical lymph nodes, and thereby improving the prognosis.[1] In this article, we reported a case of SCC involving the mandibular gingiva resembling desquamative lesion case which presented as a diagnostic dilemma due to variable clinical and radiological features mimicking different pathologies occurring in the anterior mandible.

CASE REPORT

A 48-year-old male patient reported to the Department of Periodontology, Krishna Institute of Dental Sciences, Karad, with the chief complaint of pain and burning sensation in the left lower back region of the lower jaw since 1-year. The pain was intermittent in nature. The patient reported no significant history of trauma. The patient's personnel, family, and medical history were noncontributory. All the vital signs were within the normal limits. The patient had a habit of chewing tobacco with lime once daily for 10 years.

Extra-oral examination revealed tenderness on palpation of submandibular and submental lymph nodes. On intra-oral examination, a desquamated gingival lesion [Figure 1] was seen on the marginal and attached gingiva extending from the distal aspect of 35 to mesial aspect of 37 measuring approximately about 3.5 cm × 1 cm in size and was bright red in color with slightly elevated margins and bleeding on slight provocation. All of the inspectory findings were confirmed on palpation regarding the site, shape, size, and extent of the lesion. The preoperative intraoral periapical radiograph and orthopantogram [Figures 2 and 3] revealed horizontal bone loss mesial to 35 regions, but there was no aggressive bony destruction around this area. Blood investigations rendered normal results. Based on clinical characteristics, differential diagnosis included SCC, erosive lichen planus, pemphigus, and epidermolysis bullosa.

Figure 1

Preoperative view of the lesion

Figure 2

Intraoral periapical radiograph

Figure 3

Preoperative orthopantogram

Histopathology

To obtain a final diagnosis, an incisional biopsy was performed under local anesthesia. Sections from the biopsied specimens stained with hematoxylin and eosin [Figures 4 and 5] revealed neoplastic squamous epithelial cells invading the connective tissue stroma arranged in form of Islands and sheets exhibiting increased nuclear-cytoplasmic ratio, cellular pleomorphism, nuclear hyperchromatism, individual cell keratinization, abnormal and atypical mitotic figures, and keratin pearl formation. An intense chronic inflammatory infiltrate and blood vessels of various calibers were also evident in the connective tissue stroma. On the basis of a histopathological examination of the tissue, the diagnosis was made as well differentiated SCC.

Figure 4

H and E, ×4 showing Islands of malignant squamous epithelial cells invading into connective tissue stroma

Figure 5

H and E, ×40 demonstrating individual neoplastic squamous epithelial Islands with keratin pearl formation

Treatment

To rule out metastasis in the lung, chest X-ray was advised and was found to be clear [Figure 6]. The patient underwent surgical extraction from 41 to 38 with peripheral osteotomy leaving 2–3 cm of the inferior border of the mandible [Figure 7]. Supraomohyoid neck dissection was done to excise level IA (submental lymph node), IB (submandibular lymph node), II (upper deep jugular lymph node), III (middle deep jugular lymph node) lymph nodes and submitted for histopathological investigations. On histopathological examination, all the lymph nodes were negative with T1 N1 Mx staging. Hemostasis was done and primary closure was achieved [Figure 8]. Since the case was diagnosed early, the patient was abstained from chemotherapy and radiotherapy.

Figure 6

Chest radiograph with no evidence of secondary malignancy

Figure 7

Postoperative view Figure

Figure 8

Postoperative orthopantogram

DISCUSSION

Carcinoma of the gingiva is an insidious disease that is usually painless and is often misdiagnosed as one of the many inflammatory lesions of the periodontium such as pyogenic granuloma, papilloma, or even fibroid epulis (inflammatory hyperplasia). Gingival carcinoma typically arises from keratinized mucosa in a posterior site, most often in the mandible, where it often destroys the underlying bone structure, causing tooth mobility.

Though oral SCC is a very commonly occurring lesion but SCC of gingiva is a rare entity. Early recognition of gingival SCC is of utmost importance which usually is overlooked and this could be attributed to its variable clinical appearance which may mislead the clinician resulting in differing treatment modalities.

The clinical characteristics of SCC vary from case to case and include the exophytic (verrucous or papillary), endophytic, ulcerated, leukoplastic, erythroplastic, or erythroleukoplastic forms. Depending on their extent and/or location, these lesions may cause painful symptoms and resorption of adjacent bone seen as a “moth-eaten” appearance on radiographs.[5] SCC of the gingiva is normally painless, and it is located in the keratinized portion. In advanced stages, it is aggressive and it has easy access to the infratemporal fossa.[6] According to Yoon et al.[4] the clinical aspect of oral SCC can range from a white plaque to an ulcerated lesion. Importantly, when located in the gingiva this type of malignant tumor may resemble inflammatory lesions frequently observed in this region.

In the present case, the lesion mimicked clinically as desquamative lesion but after histopathological examination it was ruled out as well-differentiated SCC. Metastasis to lung was not observed. To date, the enigmatic etiological mechanisms of oral cancers have not been elucidated. But, there are several factors that appear to contribute to the occurrence of oral cancer. Common risk factors are smoking, betel nut chewing, and alcohol consumption.[3]

One important aspect of gingival SCC is its higher risk of causing metastases and consequent death. Being more aggressive, it hence caveats the clinician for early diagnosis. According to Yoon et al.[5] and Meleti et al.[7] gingival SCC does not show a strong association with classical risk factors such as actinic radiation, tobacco use, either smoked, or chewed in its various forms, especially when associated with excessive consumption of alcohol. Otherwise, Souza et al.[8] have reported a significant association between gingival SCC and smoking and alcohol consumption.

Treatment of SCC of the gingiva is primarily surgical. Radical neck dissection, or its modification, is the standard treatment for the metastatic lymph nodes. Radiotherapy is usually not the preferred modality of treatment for early gingivobuccal complex cancer. It is used either as a postoperative adjuvant treatment or as definitive treatment for advanced cancer with or without chemotherapy. Chemotherapy has been used as neo-adjuvant, adjuvant or palliative treatment.[9]

Choosing the best therapy for SCC of the oral cavity is dependent on patient factors and tumor factors. Patient factors include the nutritional status, associated diseases, and oral behaviors, while tumor factors include its size, site, histology, and biologic behavior. In general, oral cancers are treated with surgery or radiation or both. Smaller lesions are typically treated with wide excision alone, and radiation therapy serves as a backup in the event of recurrence. For carcinomas of the gingiva, the proximity of the underlying periosteum and bone usually invites early invasion of these structures. They occasionally rapidly infiltrate and extend along the periodontal membrane, thus destroying the supporting bone. The validity of marginal bone resection combined with modified neck dissection has been confirmed.[10]

The combination of cisplatin – 5-fluorouracil (PF) has been used as a standard induction therapy; however, poor patient survival has stimulated investigation into new agents with potential activity in SCC. However, docetaxel has significant single-agent activity in SCC and has demonstrated improved survival and overall response.[11]

Regardless of advances in diagnosis and treatment during the past 40 years, the 5 years survival rate of oral SCC patients has been reported approximately 50%, which is not satisfactory despite new treatment modalities. SCC survival rate is strongly associated with mode of invasion, presence of lymph node metastasis, extra-capsular spread, surgical margins, and front grade tumor invasion.[12] Thus, the early diagnosis and treatment of carcinoma by health care providers is essential in achieving a good prognosis. The clinical and radiographic appearance of SCC may also sometimes manifest itself as a common endodontic-periodontic lesion which may result in the delay of both the diagnosis and therapy.[13]

The prognosis with gingival carcinomas depends on the histological subtype (grade) and clinical extent (stage) of the tumor. The grading of a tumor uses microscopic determination of the differentiation of the tumor cells. A well-differentiated type such as in our case is generally considered to have a favorable prognosis. But, the most important indicator of the prognosis is the clinical stage of the disease. If the neoplasm is small and localized, the 5-year cure rate is around 60–70%; however, if cervical metastasis occurs, the survival rate drops to about 25%. Therefore, early diagnosis is imperative to the successful management of the lesion.[14]

CONCLUSION

Many a times clinical presentation of diseases may be misleading the diagnosis. SCC should be diagnosed early for better prognosis as it was done in the present case. In these instances, dentist must be aware that lesions that do not respond normally to routine therapy should be biopsied for the accurate management in the interest of the patients.

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Conflicts of interest

There are no conflicts of interest.