Clear cell odontogenic carcinoma of maxilla: A case report and mini review
A 55-year-old woman reported to the Department of Oral Pathology, Dr. R. Ahmed Dental College and Hospital, Kolkata with a four month history of painless swelling in left upper jaw region. On inspection, a smooth surfaced, mucosal colored swelling of 3 cm diameter was observed with buccal cortical plate expansion extending from 23 to 25. The premolars were slightly displaced and an ulcer was observed in the interdental region on the palatal aspect []. On palpation, the swelling was non-tender, non-fluctuant, and firm in consistency. The regional teeth 24 and 25 were non-tender, but mobile. Bilateral cervical lymph nodes were not palpable. Orthopantomogram revealed a well-delineated, unilocular radiolucent lesion extending from the mesial aspect of 23-26 with divergence of roots of the regional teeth []. The patient's personal, family, and medical histories were non-contributory. The hematological tests were also within normal limits and no other systemic abnormality was observed.\nWith a provisional diagnosis of intraosseous odontogenic tumor, incisional biopsy was performed under local anesthesia. Microscopically, sections stained with H and E revealed sheets and islands of large clear cells separated by a delicate fibrous connective tissue stroma []. Under higher magnification, biphasic population of cells characterized by polygonal, clear cells and hyperchromatic, basaloid cells with eosinophilic cytoplasm were seen. Occasional islands showed peripheral palisading. Nuclear pleomorphism was minimal, and mitotic figures were rare. In addition, the fibrous connective tissue stroma exhibited some areas of hyalinization, but no fibrous capsule was identified at the periphery of the tumor [].\nThe abundant cytoplasm of the clear cells showed diastase sensitive Periodic Acid Schiff-positive granules, indicating intracytoplasmic glycogen deposition []. Tumor cells were immunoreactive for cytokeratins (CKs) 8 and 19, while non-reactive for S-100 and vimentin. Focal heterogeneous moderate immunostaining pattern was observed for CK-8 []. CK-19 on the other hand showed moderate, diffuse, heterogeneous pattern of immunoreactivity in the tumor islands []. Vimentin was strongly positive in the fibrous stromal component only [].\nFinally, a diagnosis of CCOC was made and the patient underwent radical resection of the tumor with wide surgical margins. The post-operative histopathological diagnosis was consistent with the incisional biopsy results. The patient made an uneventful recovery with no recurrence and metastasis observed 1 year post-operatively.