Carcinoma cuniculatum of the oral mucosa: a potentially underdiagnosed entity in the absence of clinical correlation

ObjectiveTo delineate the features of carcinoma cuniculatum (CC), emphasizing potential management errors.Study DesignA retrospective study examined archival cases of CC. An analysis of clinical, microscopic, and management parameters was performed.ResultsTen cases were identified, and their clinical and microscopic features were summarized. CC exhibits a sessile pink/red mildly papillary surface. Histologically, CC presents a tortuous invasive component with a more subtle papillary appearance than verrucous carcinoma.ConclusionsCC is an uncommon variant of squamous cell carcinoma distinct from verrucous carcinoma. Diagnostic delays result from misinterpretation of superficial samples or lack of awareness of the entity. Bland cytology and unusual architecture result in underdiagnosis of CC without clinicopathologic correlation. Clinicians should submit multiple deep samples of lesions displaying a cobblestone-like surface and provide a clinical photograph to the pathologist. Pathologists can avoid underdiagnosis by thorough sampling of biopsies and requesting additional tissue as needed.