Calretinin Expression in the Differential Diagnosis of Human Ameloblastoma and Keratocystic Odontogenic Tumor

Abstract

Ameloblastoma is a benign, locally aggressive epithelial odontogenic tumor that has the potential to become malignant and produce metastasis to distant sites such as lungs and kidneys. The histologic presentation can be, in some instances, mistaken for keratocystic odontogenic tumor (KCOT) (formerly known as odontogenic keratocyst). The expression of calretinin [calbindin2 (CALB2)] was investigated on both ameloblastoma and KCOT. Nineteen cases of ameloblastoma and 17 cases of KCOT were stained with calretinin antiserum 18-0211 (Zymed, San Francisco, CA). All cases (100%) of ameloblastoma showed positive calretinin staining, restricted to the neoplastic epithelial component and none (0%) of the 17 KCOTs showed positive calretinin staining. Gene expression profiling of ameloblastomas showed CALB2 expressed in the basal cell layer of columnar cells resembling preameloblasts, in all 5 of the ameloblastomas evaluated. Taken together, the results of this study strongly support calretinin as a useful immunohistochemical marker for ameloblastoma and malignant ameloblastoma and it can also be used in the differential diagnosis of KCOT.

Primordial Odontogenic Cyst with Induction Phenomenon (Zonal Fibroblastic Hypercellularity) and Dentinoid Material Versus Archegonous Cystic Odontoma: You Choose!

“…Interestingly, calretinin appears to be a specific immunohistochemical marker for neoplastic ameloblastic epithelium since it has been identified in 93.5 % of multicystic and 81.5 % of unicystic ameloblastomas [2] but not in odontogenic cysts [3]. In the study by DeVilliers et al [4] comparing the calretinin immunohistochemical profile of ameloblastomas and OKCs (KCOTs), it was concluded that all (19/19) ameloblastomas were positive in contrast to 0/17 of the OKCs (KCOTs). Similarly, Anandani et al [5] detected immunopositivity for calretinin in 16/20 ameloblastomas but only in 1/20 OKCs (KCOTs).…”

“…Multiple sections were evaluated and the epithelial features were consistent in all sections. Be that as it may, to further investigate the possibility of ameloblastoma, multiple sections were immunohistochemically assessed for calretinin which can be identified in ameloblastomas but not in odontogenic cysts [2][3][4][5]. Besides calretinin, and in order to erase any doubt regarding the fibroblastic origin of spindle cells in the subepithelial induction-like zone, immunohistochemical staining for S100 protein and smooth muscle actin (SMA) were performed.…”

Botryoid Odontogenic Cyst: A Diagnostic Chaos

“…CD56 expression was seen in the cytoplasm of peripheral cells of the follicles faintly. Altini et al, reported expression of calretinin in 81.5% of unicystic ameloblastomas and 93.5% of multicystic ameloblastomas whereas no expression was seen in residual cysts, dentigerous cysts, and odontogenic keratocysts except for a study by Piattelli et al, were calretinin positivity was seen in the proliferating epithelium in Odontogenic keratocyst [7][8][9]. Careful surgical excision is the treatment of choice for BOC and conservative enucleation is contraindicated as the recurrence rate in BOC is around 34% [1], which is due to the difficulty in removing or failure to remove the entire multilocular lesion during surgery.…”

An Insight into the Histopathology of Oral Neoplasms with Basaloid Morphology and a Working Classification

“…Calretinin, a 29 KDa protein, has been found to show positive expression in neoplastic proliferation of ameloblastic epithelium, specifically staining the stellate reticulumlike cells of ameloblastoma. [15][16][17] Calretinin is considered as an additional important marker to differentiate PA from IOBCC. tumors because of the differences in prognosis and potential differences in treatment.…”