Evaluation of Proliferative Marker Ki-67 in Adenoid Cystic Carcinoma: A Retrospective Study.

AIM: Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin. Although the histologic appearance of ACC is low grade, management of this malignancy is a distinct therapeutic challenge because of its tendency for perineural involvement and potential for distant metastasis. Ki-67 antigen is expressed during the G1, S, G2 and M phases in the cell cycle but is absent in the quiescent G0 phase in tissue sections. Aim of the study was to review hematoxylin and eosin stained slides in order to confirm the previous histopathological diagnosis as per the criteria given by World Health Organisation (WHO) and to evaluate the expression of cell proliferation marker, Ki-67 antigen in Adenoid cystic carcinoma and correlate the expression of Ki-67 antigen histopathologically with different grades in Adenoid cystic carcinoma. MATERIALS AND METHODS: Tissue samples of 32 cases (12 males and 20 females) were selected from minor salivary glands with age range from 21 to 70 years. Two paraffin-embedded sections of these total 32 cases each of 4 µm thick were cut on a rotary microtome. One section was stained using hematoxylin and Eosin (H&E) and the other was used for Immunohistochemical staining with Ki-67 antigen. RESULTS: Among these 32 cases of Adenoid cystic carcinoma, Histologically 14 (43.75%) tumors were classified in grade I, 8 (25%) were in grade II, and 10 (31.25%) were in grade III. The average percentage of Ki-67 expression was 27.12% in grade I, 34.43% in grade II and 38.45% in grade III. CONCLUSION: Ki-67 immunoreactivity increased with increase in histopathological grades of ACC. CLINICAL SIGNIFICANCE: Since Ki-67 is a useful marker for assessing the proliferative potential of tumors, the prognosis of patients can definitely be predicted.

Immunohistochemical Detection of Proliferative Marker Ki-67 in Benign and Malignant Salivary Gland Tumors.

Introduction: Salivary gland tumors are the most histologically heterogeneous group of tumors with the greatest diversity of morphologic features among their cells and tissues. The present study was aimed at assessing the validity of Ki-67, a cell proliferation marker, as a prognostic factor in benign and malignant salivary gland tumors and to study whether it is related to age, sex, anatomical site, and size of the lesion in salivary gland tumors. Materials and methods: A retrospective study consisted of benign salivary gland tumors (BSGTs) (n = 15), malignant salivary gland tumors (n = 18), and normal salivary gland parenchyma (n = 15). Results: There was a significant difference of Ki-67 labeling index (LI, %) in normal salivary gland parenchyma, BSGTs, and malignant salivary gland tumors. The Ki-67 LI (%) in normal salivary gland parenchyma is negligible (0.27 ± 0.31%), whereas malignant salivary gland tumors showed very high Ki-67 LI (%) of 18.79 ± 18.06% compared with BSGTs being 0.76 ± 2.02%. There was a significant correlation statistically of mean ± standard deviation (SD) of Ki-67 LI (%) with the age of the patients being the maximum (32.68 ± 15.87%) in the 50 to 59 years age group, whereas sex, site of the lesion, and size of the lesion in salivary gland tumors had no significant correlation. Conclusion: The Ki-67 is a useful marker for assessing prolif-erative potential of tumors. Clinical significance: The Ki-67 LI% can be used as a reliable adjuvant diagnostic tool to differentiate between the subtypes and grading of certain malignant tumors, such as mucoepi-dermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC), and acinic cell carcinoma (AcCC), which are usually difficult to diagnose on histopathological criteria alone. Keywords: Immunohistochemistry, Ki-67, Salivary gland neoplasms.

Verrucous Carcinoma with Oral Submucous Fibrosis: A Rare Case with Brief Review.

Oral verrucous carcinoma (VC) is a variant of well differentiated oral squamous cell carcinoma (OSCC) characterized by exophytic over growth. Oral submucous fibrosis (OSMF) is a potentially malignant disorder associated with chronic betel nut chewing habit. The development of OSCC is seen in one-third of the OSMF patients, but the development of VC is rare in such patients. There are very few cases of OSMF with VC reported in literature. Here, present a rare case of an elderly patient with VC in conjunction with OSMF.