[Basaloid squamous cell carcinoma in gingiva: a case report]

[Clinicopathological study in 28 cases of oral basaloid squamous cell carcinomas]

OBJECTIVE

To investigate the clinicopathologic features and prognostic factors in oral basaloid squamous cell carcinoma.

METHODS

Retrospective analysis of oral basaloid squamous cell carcinomas patients who underwent tumor resection during the period from January 2002 to December 2020 in the authors' hospital, especially the clinicopathologic characteristics of 28 cases with confirmed diagnosis and follow-up data. Immunohistochemistry was performed to define the helpful markers for differentiation diagnosis. The factors influencing the prognosis were evaluated based on Kaplan-Meier method.

RESULTS

The tongue and mouth floor (11 cases, 39.3%) were the most frequently involved sites, followed by gingiva (6 cases, 21.4%), buccal (5 cases, 17.9%), palate (4 cases, 14.3%), and oropharynx (2 cases, 7.1%). The majority of basaloid squamous cell carcinomas were in advanced stage, with 12 cases in stage Ⅱ and 16 cases in stages Ⅲ-Ⅳ. Twelve of 28 patients were identified to have cervical lymph node metastasis, which was confirmed by histopathological examination. The incidence rate of lymph node metastasis was 42.9% (12/28). Nine tumors recurred, with one metastasized to the lung. At the meantime, the 28 conventional squamous cell carcinomas were matched with the same stage, among which 13 cases were identified with cervical lymph node metastasis. The incidence rate of lymph node metastasis was 46.4% (13/28). Five cases recurred, with two cases that metastasized to the lung and one to the brain. The 5-year overall survival rates of the basaloid squamous cell carcinoma and conventional squamous cell carcinoma patients were 54.6% and 53.8%, respectively. Histopathologically, basaloid cells consisted of tumor islands without evident keratinization but frequently with comedo-like necrosis within the tumor islands. CK5/6 and P63 exhibited strongly positive in all the 28 cases, whereas neuroendocrine markers, CgA and Syn, were negative. Eight cases positively expressed P16; one case showed focal SOX10 positive but CK7 negative.

CONCLUSION

The majority of oral basaloid squamous cell carcinomas present in advanced stage with a high tendency to lymph node metastasis, but the overall survival rates are not significantly different from conventional squamous cell carcinomas matched with the same stage. The human papilloma virus (HPV), as HPV-positivity rate is high, correlates to good prognosis. In addition, CK7 & SOX10 immunohistochemistry could contribute to differential diagnosis for basaloid squamous cell carcinoma with solid adenoid cystic carcinoma.

Basaloid squamous cell carcinoma of gingiva: A rare case report

Basaloid squamous cell carcinoma (BSCC) is an exceptional, aggressive variant of squamous cell carcinoma (SCC) because of its unique histological feature and an ominous clinical behavior. Recently, it has been recognized as a high-grade SCC. The most preferential site of occurrence is the upper aerodigestive tract. Because of its aggressive behavior and tendency to metastasize, BSCCs are considered to have poor prognosis. We present a BSCC case in a 60-year-old male, which was clinically diagnosed as an aggressive inflammatory lesion with a differential diagnosis of granulomatous lesion, involving the mandibular anterior gingiva. Till now, only 17 cases of BSCC with gingival involvement have been reported in the literature. Here, we present one additional case of BSCC involving gingiva.