Proliferative activity and subtyping of calcifying odontogenic cyst

Immunohistochemical analysis of p53 and PCNA expression in calcifying odontogenic cyst

Calcifying odontogenic cyst (COC) is a developmental odontogenic cyst in the jaw. Because of its diverse histopathologic features and biological behavior, there has long been confusion with regard to its nature as a cyst or neoplasm. This study evaluated the proliferative activity of 57 COC samples, including simple cyst (10 cases), cystic neoplasm (34 cases), solid neoplasm (6 cases) and combined lesion (7 cases) by p53 and PCNA immunohistochemical staining. For assessment of p53 and PCNA positivity, the number of positively stained cells with brown-stained nuclei was counted in 1000 cells from each sample. p53 and PCNA expression in the solid neoplasm subtype were significantly higher when compared to cystic neoplasm and simple cyst (P < 0.05). The lowest p53 and PCNA expression was found in the simple cyst subtype. p53 and PCNA expression in the basal and suprabasal layers was significantly higher in the solid subtype when compared to others, and the difference between COC groups was significant. The results demonstrated that within benign types of COC, the amount of p53 and PCNA in proliferative epithelium is significantly higher when compared to non-proliferative epithelium. p53 and PCNA markers are possible parameters for differentiation of COC subtypes.

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

Background

Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.

Methods

A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.

Results

The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.

Conclusion

The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.

Calcifying odontogenic cyst: clinicopathological features and immunohistochemical profile of 10 cases

BACKGROUND

Calcifying odontogenic cyst (COC) is an uncommon odontogenic lesion with few studies describing its immunohistochemical profile and proliferative activity reported in the literature.

METHODS

Clinical and histological features and immunohistochemical expression of cytokeratins, Mel-CAM (CD146), bcl-2, PCNA and ki-67, in 10 cases of COC were studied.

RESULTS

All 10 cases affected the maxilla, eight intraosseous and two peripheral. Five central cases were cystic and three were cystic associated with odontoma, and the two extraosseous showed solid histological pattern; immunohistochemistry was positive for cytokeratins 8, 14, 19, AE1/AE3 and 34betaE12 and bcl-2 in all cases, and Mel-CAM in six cases. Proliferative activity was greater in the epithelium of central cystic COC in relation to COC associated with odontoma and peripheral lesions.

CONCLUSION

Calcifying odontogenic cysts showed odontogenic cytokeratin profile and bcl-2 and Mel-CAM expression indicate that these proteins may be involved in the development of COC. There were no recurrences after surgery, irrespective of their proliferative activity.