Multiple verrucous carcinomas of the oral cavity

Abstract

The author herein reports a case of multiple verrucous carcinomas (VCs) of the left lower gingiva. A 78-year-old man was admitted to our hospital because of gingival tumor. A biopsy revealed severe dysplasia. Surgical resection was performed. Grossly, there were three verrucous lesions (25, 20, 10 mm) in the left lower gingiva. Histologically, 2 tumors (4, 2 mm) were found in addition to the grossly visible 3 tumors. All the 5 tumors were VCs. The tumors showed verrucous and papillary proliferation of squamous epithelium with little cellular atypia. No invasive features were recognized. The dermis showed lymphocytic infiltration. The surrounding mucosa showed many broad foci of squamous cell carcinoma in situ and severe dysplasia (high grade intraepithelial neoplasm). Gradual merges between the VCs and squamous cell carcinoma in situ or severe dysplasia were frequently recognized. Immunohistochemically, the VC tumor cells and squamous lesions were negative for human papilloma virus antigens. P53 protein was expressed in all the VCs and squamous epithelial lesions: it was accentuated in the basal and suprabasal cells of VC. Ki-67 antigen was also expressed in the 5 VCs and in the squamous lesion, and Ki-67 labeling index ranged from 8 to 16 % in VC and from 37 to 62 % in the squamous lesions. These data support the multicentric nature of VC and that the severe dysplasia-carcinoma in situ sequence have been proposed in the etiology of VC.

Keywords: Histology; Immunohistochemistry; Oral cavity; Pathology; Verrucous carcinoma.

Fig. 1

Gross findings of the resected left lower gingival specimen. There were three verrucous tumors (arrows)

Fig. 2

Low power view of verrucous carcinomas. Verrucous proliferation of squamous epithelium is evident. The cellular atypia is mild or minimal. a The 25 mm tumor. b The 4 mm tumor

Fig. 3

Individual keratinization is recognized in the verrucous carcinoma. The cellular atypia is minimal. HE, ×200

Fig. 4

The basal cell and suprabasal cells show mild atypia in a verrucous carcinoma. Lymphocytic infiltration is seen in the dermis. HE, ×200

Fig. 5

Squamous cell carcinoma in situ in non-verrucous carcinoma areas. There are cellular atypia, loss of polarity, mitotic figures, individual keratinization, loss of differentiation, and apoptotic bodies are seen. HE, ×200

Fig. 6

Severe dysplasia in non-verrucous carcinoma areas. Atypical cells with hyperchromatic nuclei and with loss of polarity occupy the lower five sixths of the squamous layer. HE, ×200

Fig. 7

Direct transition between verrucous carcinoma and squamous cell carcinoma in situ. The squamous element is squamous cell carcinoma in situ. HE, ×200

Fig. 8

Ki-67 labeling is high in the basal and suprabasal cells in a verrucous carcinoma. ×100