Histomorphometric comparative study of blood vessels and their pattern in follicular cyst, odontogenic keratocyst, and ameloblastoma.

OBJECTIVE: The present study aimed at assessment and histomorphometric analysis of intratumoral and peritumoral (cystic) blood vessels in odontogenic lesions and their pattern on their clinical behavior by immunohistochemistry and morphometry. METHODS: In a descriptive and analytical cross-sectional study, 45 paraffin blocks of ameloblastoma, odontogenic keratocyst, and follicular cyst were selected and stained immunohistochemically for CD34. In each slide, images of 3 microscopic fields with the highest microvessel density in intratumoral and peritumoral (cystic) areas were captured at 40× magnification with attached camera system. Inner vascular diameter (IVD) and outer vascular diameter (OVD), cross-sectional area (CSA), and the wall thickness (WT) of the vessels were measured with Motic Plus 2 software. The vascular pattern in odontogenic lesions was analyzed. RESULTS: Outer vascular diameter, IVD, and CSA of the vessels in peritumoral (cystic) areas were greater in ameloblastoma than keratocyst (P = 0.001) and follicular cyst (P < 0.001). However, WT of the blood vessels did not show any significant statistical difference among the 3 odontogenic lesions (P = 0.05). The differences in OVD, IVD (P = 0.8), CSA (P = 0.6), and WT (P = 0.4) of the blood vessels in intratumoral (cystic) areas were not statistically significant. The blood vessel pattern was circumferential in ameloblastoma, and it was directional in keratocyst and follicular cyst. CONCLUSIONS: Morphometric specifications of blood vessels (IVD, OVD, CSA) and their pattern in peritumoral (cystic) areas may influence the aggressive clinical behavior of ameloblastoma in comparison with keratocyst and follicular cyst.

Quantitative and qualitative analysis of argyrophilic nuclear organizer regions in follicular cyst, keratocystic odontogenic tumor and ameloblastoma.

BACKGROUND: Multicystic ameloblastoma is a benign odontogenic tumor that exhibits a more aggressive behavior than keratocystic odontogenic tumor (KCOT) and follicular cyst. AIM: The purpose of the study was to evaluate the proliferation index nuclear organizer regions (NORs) and their distribution among the four odontogenic lesions with known different clinical invasive behavior. STUDY AND DESIGN: In a descriptive-analytical cross-sectional study, 60 paraffin blocks of odontogenic lesions were prepared for silver nitrate staining. MATERIALS AND METHODS: For the quantitative analysis, 100 cells were counted at ×100 and the mean value was calculated. The morphometric analysis of NORs showed that they can be distributed into normal (round to oval-shaped) and abnormal (large, bean-shaped and cluster-shaped) groups. One-way analysis of variance (ANOVA) and multiple comparison with Tukey test were used for the statistical analysis of the results. RESULTS: The argyrophilic NOR (AgNOR) numbers in multicystic ameloblastoma, unicystic ameloblastoma, KCOT, and follicular cyst were 7.4 ± 2.7, 6.1 ± 2.56, 4.7 ± 1.84, and 2.82 ± 1.052, respectively. The difference between ameloblastoma (unicystic and multicystic types) and either_KCOT, or follicular cyst was statistically significant (P<0.001) and, (P=0.001), respectively. In follicular cysts, normal AgNOR dots were not detected outside the nuclei. NOR histological patterns of KCOT were large, bean shaped and rarely cluster shaped and it was cluster-shaped in multicystic and unicystic ameloblastoma. CONCLUSION: The current study suggests that determination of clinical behavior of ameloblastoma in comparison with KCOT and follicular cyst in silver nitrate staining is related to higher proliferation activity and different NORs' distribution pattern. However, further clinical follow-up studies must be performed to prove this.

Microvessel density in follicular cysts, keratocystic odontogenic tumours and ameloblastomas.

PURPOSE: Multicystic ameloblastoma is a benign epithelial odontogenic tumor that exhibits a more aggressive behavior than follicular cyst and keratocystic odontogenic tumor (KCOT). The aim of this study was to perform an immunohistochemical evaluation of the mean microvessel density (MVD) effect on clinical behavior of odontogenic lesions and to determine whether peritumoral or intratumoral MVD has a more prominent role in clinical behavior of odontogenic lesions. METHODS: In a descriptive-analytic cross-sectional study, 45 paraffin blocks of mentioned lesions were selected and stained immunohistochemically with CD34. Mean MVD, peritumoral and intratumoral MVD for each odontogenic lesion was investigated and compared with each other. ANOVA and Kruskal Wallis were used for the statistical analysis of the results. RESULTS: Mean MVD was 40.8 ± 15.9, 25.3 ± 5.4, and 9.4 ± 3.52 in ameloblastoma, keratocystic odontogenic tumor , and follicular cyst, respectively. Mean MVD difference between the above mentioned lesions was statistically significant. (p < 0.001) In all the odontogenic lesions, Intratumoral MVD was higher than peritumoral (pericystic) areas. (p = 0.001) CONCLUSION: There was an increase of mean MVD in multicystic ameloblastoma in comparison to keratocystic odontogenic tumor and follicular cyst and it may be concluded as one of the main factors in multicystic ameloblastoma aggressive behavior. Intratumoral (intracystic MVD) has a more prominent role in growth and clinical behavior of mentioned odontogenic lesions. This supports the hypothesis that the early stages of growth and development of follicular cyst, KCOT and multicystic ameloblastoma may share some similarities regarding angiogenesis.

Myofibroblast stromal presence and distribution in squamous epithelial carcinomas, oral dysplasia and hyperkeratosis.

PURPOSE: Stromal elements play a key role in growth and development of different neoplasms. Myofibroblasts are the major components and occur in stromal tissue during carcinogenesis processes. The purpose of this study was to review the frequency and the distribution pattern of myofibroblasts(αSMA-positive) in the stroma of squamous epithelial carcinoma and to compare values with those for with oral dysplasia and hyperkeratosis. METHODS: we evaluated αSMA protein frequency in hyperkeratosis (N =18), oral epithelial dysplasia (N=18) and oral squamous cell carcinoma (N=18) using immunohistochemistry. RESULTS: αSMA-positive expression was observed in 67% of OSCC tissue samples with network and spindle patterns, whereas it was seen in 22% with a focal pattern in dysplasia and in 6% with a scanty pattern in hyperkeratosis cases. CONCLUSION: These findings suggest that an increase in number of myofibroblasts and change in their distribution pattern occurs during carcinogenesis which can be an expression of their role in tumor invasive characteristics.