Assessment of biologically aggressive, recurrent glandular odontogenic cysts for mastermind-like 2 (MAML2) rearrangements: histopathologic and fluorescent in situ hybridization (FISH) findings in 11 cases.

BACKGROUND: Glandular odontogenic cyst (GOC) demonstrates a significant predilection toward localized biologic aggressiveness and recurrence. GOC shares certain histopathologic features with intraosseous mucoepidermoid carcinoma (IMEC). The current investigation evaluates a group of recurrent, biologically aggressive GOCs to determine whether any cases demonstrated unique histologic features or mastermind-like2 (MAML2) rearrangements common to IMEC.

METHODS: Microscopic slides from 11 previously diagnosed GOCs were stained with hematoxylin and eosin and assessed by 2 study participants for 10 classic histopathologic features required to establish a diagnosis of GOC. Cases were evaluated utilizing break-apart fluorescent in situ hybridization (FISH) analysis for the presence of MAML2 gene rearrangements. Clinical and demographic data on all patients were recorded.

RESULTS: The mean age for patients included in the study was 55.27 years with a range of 36 to 72 years. The most common presenting symptom was a jaw expansion, and all cysts presented initially as a unilocular or multilocular radiolucency. Cysts displayed a minimum of 6 of 10 histologic parameters necessary for a diagnosis of GOC. One case demonstrated MAML2 rearrangements by FISH. That case also showed marked ciliation of cyst-lining epithelial cells and extensive mucous-secreting goblet cell proliferation.

CONCLUSION: Findings in the current study are in concert with previous investigations, and although this study finds only limited molecular evidence to support the premise that recurrent biologically aggressive GOCs are a precursor to IMEC, detection of MAML2 rearrangements in 1 case suggests that such a theoretic transition, while rare, is possible.