Central mucoepidermoid carcinoma arising directly from a glandular odontogenic cyst of the mandible: a case report

Background Central mucoepidermoid carcinoma (MEC) is a rare salivary gland tumor that affects the jawbone. Glandular odontogenic cyst (GOC) is also a rare odontogenic developmental cyst with glandular differentiation. GOC shares some histological features with central MEC, and a pre-existing GOC can develop into central MEC. Here, we present a rare case of central MEC developed directly from a pre-existing GOC of the mandible. Case presentation A 67-year-old Japanese man presented with a cystic lesion in the right third molar region. Histologically, the biopsy specimen demonstrated both typical findings of a GOC component lined with non-keratinized squamous epithelium and a recognizable component of central MEC consisting of polycystic nests with mucous cells, intermediate cells, and epidermoid cells in the cyst wall. The results from the immunohistochemistry for cytokeratin (CK) profiling demonstrated that, while both central MEC and GOC expressed CKs 7, 14, 18, and 19, CK13 was interestingly exclusively expressed in GOC. Fluorescence in-situ hybridization (FISH) revealed the rearrangement of the Mastermind like (MAML)-2 gene in both the MEC and GOC components. Conclusions Our case suggests that central MEC and GOC may be in the same spectrum of diseases caused by the rearrangement of the MAML-2 gene. However, given that the expression profile of CK13 was completely different between central MEC and GOC, they can be considered as separate tumors. Overall, we demonstrated a rare case in which central MEC may have originated directly from the GOC.

Unique case of glandular odontogenic cyst showing mucoepidermoid carcinoma-like islands in cystic wall

Glandular odontogenic cyst (GOC) is a very rare jaw cyst accounting for 0.2% of all odontogenic cysts. It presents usually in adults with a slight male predominance. It shows radiological, histopathological and even immunohistochemical overlap with low grade intraosseous mucoepidermoid carcinoma (MEC) but their distinction is crucial. A 57-year-old woman with bilocular radiolucency in the anterior mandible crossing the midline is described here. Microscopy features were consistent with glandular odontogenic cyst but multiple MEC-like islands were seen in the capsule, creating a diagnostic head trip with low grade intraosseous MEC. However, the absence of cellular atypia and epidermoid and intermediate cells led to a final diagnosis of GOC, with close follow-up of the patient recommended. This rare finding shows the relation between GOC and MEC or the origin of MEC from GOC.

Central Mucoepidermoid Carcinoma Arising Directly From a Glandular Odontogenic Cyst of the Mandible: A Case Report

BackgroundCentral mucoepidermoid carcinoma (MEC) is a rare salivary gland tumor that affects the jaw bone. Glandular odontogenic cyst (GOC) is also a rare odontogenic developmental cyst with glandular differentiation. GOC shares some histological features with central MEC, and a pre-existing GOC can develop into central MEC. Here, we present a rare case of central MEC developed directly from a pre-existing GOC of the mandible. Case presentationA 67-year-old Japanese man presented with a cystic lesion in the right third molar region. Histologically, the biopsy specimen demonstrated both typical of a GOC component lined with non-keratinized squamous epithelium and a recognizable component of central MEC consisting of polycystic nests with mucous cells, intermediate cells, and epidermoid cells in the cyst wall. The immunohistochemistry for cytokeratin (CK) profile results demonstrated that while both central MEC and GOC expressed CKs 7, 14, 18, and 19, interestingly CK13 was only expressed in GOC. Fluorescence in-situ hybridization (FISH) revealed the rearrangement of the Mastermind like (MAML)-2 gene in both MEC and GOC components. ConclusionsOur case suggests that central MEC and GOC may be in the same spectrum of diseases caused by rearrangement of the MAML-2 gene. At the same time, the expression profile of CK13 was completely different in both central MEC and GOC. This also suggests that central MEC is a distinct tumor from GOC. Thus, we demonstrated the rare case that central MEC may have originated directly from the GOC.