Ghost Cell Odontogenic Carcinoma of the Anterior Maxilla with ARID1A Mutation: A Case Report and Literature Review.

Background: Ghost cell odontogenic carcinoma (GCOC) is a rare malignant neoplasm that has a propensity for the maxilla, with a male predilection, and approximately sixty-four cases reported to date. We herein report the sixty-fifth case in a 38-year-old male patient with maxillary lesion, along with an extensive literature review.

Case presentation: A 38-year-old male patient was referred to the oral and maxillofacial surgery clinic at King Fahad Medical City (KFMC), Riyadh, Saudi Arabia, with a nonhealing proliferative growth in the anterior maxilla for two months. Microscopically, the lesion showed ghost cells and dentinoid deposition with ameloblastoma-like epithelial linings and malignant features, including nuclear pleomorphism, increased mitosis, necrosis, perivascular invasion, and invasion into adjacent bone. The tumor cells were reactive to CAM5.2, p63, CK5/6 and CK19, with CK5/6 and CK19 being positive in the peripheral area in a ring-like pattern in the ghost cell region. Additionally, nuclear staining of beta-catenin was detected while next generation sequencing revealed mutations in the CTNNB1 variant c.110 C > G p.(Ser37Cys) and the ARID1A variant c.4420 C > T p. (Gln1474*), respectively, at the high variant allele. The patient was treated with surgical excision and bilateral cervical lymph node dissection followed by adjuvant radiotherapy, and the patient was free of disease after 30 months.

Conclusion: Ghost cell odontogenic carcinoma is a rare aggressive odontogenic tumor that can be challenging to diagnose, especially with incisional biopsy. CTNNB1 is a consistent gene mutation in this tumor; however, ARID1A was reported for the first time in our patient.