Oral carcinoma cuniculatum, the great mimicker: Report of a challenging case and literature review

Oral carcinoma cuniculatum (OCC) is a rare and locally invasive well‐differentiated variant of squamous cell carcinoma. To date, 74 cases affecting the oral cavity were reported in English‐language literature. We report a case of maxillary OCC in a 71‐year‐old woman and review the demographic, etiological, clinicopathological, therapeutic and prognostic features of the OCC cases published in the English literature. From the 75 cases evaluated, there was no predilection for sex, and the highest incidence was between the seventh and tenth decades of life. Use of alcohol (17.3%), tobacco (29.3%), both (6.7%), and betel chewing (5.3%) were related in some cases. The clinical presentation was variable, and the gingiva and mandibular alveolar ridge were the most affected sites (50.7%). Inconclusive result or misdiagnosis in the initial histopathological examination was reported in more than 40% of cases, which required deeper or more representative biopsies for the definitive diagnosis. Radical surgery was the treatment of choice for 88.0% of cases. Overall, 10.7% of cases had cervical lymph node metastasis and 17.3% had recurrence after initial treatment, with only one death (1.3% of the cases). In conclusion, the wide variety of clinical presentations, lack of cytological atypia in most cases and need for deep incisional biopsies make the diagnosis of OCC challenging. Radical surgery is the main therapeutic modality and local recurrence after initial treatment occurs in less than 20% of cases. Although locally aggressive, regional and distant metastases are rare and the prognosis is good.