Clinicopathologic analysis and syndecan-1 and Ki-67 expression in calcifying cystic odontogenic tumors, dentinogenic ghost cell tumor, and ghost cell odontogenic carcinoma.

Objective: Benign and malignant tumor cells can express altered adhesion properties, and these features can be associated with their proliferative and invasive characteristics. This study aimed to evaluate syndecan-1 and Ki-67 expression in ghost cell-containing odontogenic tumors.

Study Design: Clinical data were retrieved from laboratory records, and hematoxylin-eosin-stained slides and sections, labeled with monoclonal antibodies anti-syndecan-1 and anti-Ki-67 using the immunoperoxidase technique, were evaluated.

Results: Included were 21 central calcifying cystic odontogenic tumors (CCOTs) (4 associated with odontoma), 2 peripheral CCOTs, 1 dentinogenic ghost cell tumor, and 1 ghost cell odontogenic carcinoma (GCOC). Syndecan-1 was mainly expressed in cells resembling stellate reticulum and in stromal cells from the fibrous capsule. The mean Ki-67 labeling index was 4.1% (49.3% for GCOC), but it was not associated with syndecan-1 expression.

Conclusions: Syndecan-1 is variably expressed in cells resembling the stellate reticulum, stromal cells, and basal cells and might be associated with the biology of these tumors.