A case of squamous cell carcinoma (SCC) occurring in the maxillary gingiva with an interesting histopathological appearance is reported.
A 58-year-old female visited our hospital with the chief complaint of spontaneous pain of the right maxillary gingiva. Physical examination revealed ulcer formation of the right lateral incisor and canine region of the maxilla.
Radiographic examination showed that the alveolar bone of this lesion was absorbed.
As a result of histopathological analysis, it was found that this lesion consised of both SCC cells and clear cells and many inflammatory cells had infiltrated the tumor tissue, SCC cells were of the well-differentiated type and formed cancer nests, which continued to the oral epithelium. Clear cells were observed in the periphery of these nests and contained cytoplasmic glycogen that was PAS positive, as well as diastase-digestible granules. Moreover, these clear cells were formed gradually and continuously from the cancer nests. These histological findings strongly suggested that the SCC cells might be transformed into the clear cells due to the effects of infiltrating inflammatory cells. The tumor was wholly resected under general anesthesia and the patient has been in good condition without relapse for 2 years and 4 months since the operation.