Clear Cell Odontogenic Carcinoma of the Mandible Harboring EWSR1 Rearrangement: Report of a Massive Jaw Tumor and Review of Diagnostic Considerations

Abstract

Clear cell odontogenic carcinoma (CCOC) is a low-grade malignant neoplasm that affects the jaws. We report an 18 cm massive case of mandibular CCOC in a 43-year-old female. The tumor was composed of nests and cords of round to polygonal monomorphic clear cells separated by prominent stromal hyalinization. Immunohistochemically, the tumor cells showed focal cytokeratin 5/6 positivity and intracytoplasmic PAS-positive granules and were negative for S100 and after diastase treatment (PAS-D). Molecularly, this case was positive for EWSR1 rearrangement by FISH. The following should be included in the histopathological differential diagnosis: hyalinizing clear cell carcinoma of the salivary gland, clear cell variant of central mucoepidermoid carcinoma, clear cell variant of calcifying epithelial odontogenic tumor, and metastatic renal cell carcinoma. CCOC is a rare entity, with only 79 cases reported in the mandible. This case highlights the propensity for CCOC to exhibit invasiveness, destructive nature, and facial disfigurement if left untreated.

Recurring Clear Cell Odontogenic Carcinoma Involving Vertebra and Pleura: A Case Report and Literature Review

“…4 Metastasis were reported in approximately 19% cases, including local lymph node or distant metastasis. [7][8][9][10][11] The tumor cells often penetrate the cortical bone and infiltrate the soft tissue, and many fatal cases have been reported. 11,12 According to the 2017 WHO classification, the biological behaviors of clear cell odontogenic carcinoma range from indolence to aggression.…”

“…8,17,27 EWSR1 gene rearrangement has been reported in clear cell odontogenic carcinoma in past decade. 7,9,10,12,28,29 Known fusion partners of EWSR1 in clear cell odontogenic carcinoma include ATF1, 7,12,28-30 CREB1, 29 and CREM. 9 The differential diagnosis of clear cell odontogenic carcinoma includes odontogenic tumors with clear cell differentiation variants, such as ameloblastoma, calcifying epithelial odontogenic tumor, and squamous odontogenic tumor (Table I).…”

“…8,17,27 EWSR1 gene rearrangement has been reported in clear cell odontogenic carcinoma in past decade. 7,9,10,12,28,29 Known fusion partners of EWSR1 in clear cell odontogenic carcinoma include ATF1, 7,12,28–30 CREB1, 29 and CREM. 9…”

Clear cell odontogenic carcinoma of jawbone diagnosed by fluorescence in situ testing in Ewing sarcoma RNA binding protein 1 gene rearrangements: A rare case report

“… 1 CCOC presents most commonly in women in their 50s. 2 In the early stage of CCOC, the patient has only limited or non-specific symptoms, such as swelling, pain, or loosening of teeth. Aggressive invasion and cervical and pulmonary lymphatic metastasis have been reported with disease progression.…”