Asymmetrical proliferative pattern loss linked to cyclin D1 overexpression during malignant transformation of the lip epithelium.

BACKGROUND: There is inadequate knowledge on the involvement of oncogenic mechanisms linked to the cyclin (CCND1) gene in lip squamous cell carcinoma (LSCC). OBJECTIVE: The aim of this study was to analyse the implication of cyclin D1 in the malignant transformation of lip lesions. METHODS: We immunohistochemically studied 45 actinic cheilitis cases (15 mild dysplasia, 15 moderate dysplasia, 15 severe dysplasia/carcinoma in situ), 30 LSCC cases with adjacent non-tumour epithelium and 15 normal oral epithelium samples for detection of cyclin D1, ß-catenin and Ki-67. RESULTS: Cyclin D1 and Ki-67 expressions were significantly increased in the basal layer of premalignant epithelia and peripheral layers of tumour nests vs. CONTROLS: Premalignant epithelia had lost their asymmetrical proliferative pattern. CONCLUSION: Lip carcinogenesis was associated with loss of the asymmetrical proliferative pattern, a preventive mechanism against lip oncogenesis, and with cyclin D1 overexpression.

Necrotizing sialometaplasia of palate: a case report.

Background. Necrotizing sialometaplasia (NS) is an uncommon benign reactive necrotizing inflammatory process involving minor salivary gland that often mimics malignancy both clinically and histopathologically. Case Report. We report the case of a healthy 26-year-old man with a painless swelling in the hard palate near the middle raphe, asymptomatic, well limited, and raised edges. The patient was submitted to incisional biopsy and histopathological examination. The histological diagnosis was necrotizing sialometaplasia. Discussion. The clinical and histological similarity between this entity and a malignant lesion implies a risk of unnecessary or mistreatment. Therefore, clinicians and pathologists should be aware of this lesion as to avoid errors in the diagnosis and treatment of this benign pathologic condition.