I. van der Waal

Deregulated expression of p16INK4a and p53 pathway members in benign and malignant myoepithelial tumours of the salivary glands

Aims:u2002 Myoepithelial salivary gland tumours are uncommon and follow an unpredictable biological course. The aim was to examine their molecular background to acquire a better understanding of their clinical behaviour.

Polyacrylamide soft tissue filler nodule mimicking a mucoepidermoid carcinoma

A 39-year-old woman is described in whom histopathologic examination of a nodule of the cheek mucosa was suggestive of a mucoepidermoid carcinoma. Only after the availability of a wider surgical specimen was a distinct foreign body reaction to polyacrylamide soft tissue filler observed. On inquiry, the patient admitted to having this filler injected into her nasolabial folds 3 years previously.

Epidemiology of ameloblastomas of the jaws; a report from the Netherlands

Objectives: To provide epidemiological data of ameloblastomas of the jaws in the Netherlands over a 25-year time period (1985-2010) and to compare these data with data from other parts of the world. Material and Methods: The data of all patients diagnosed with a primary ameloblastoma of the jaws in the Netherlands in the period 1985-2010 have been retrieved from the nationwide histopathology and cytopathology network and registry in the Netherlands (PALGA). The pathology reports were screened and only those cases were included in which a distinct diagnosis of primary, histopathologically benign, intraosseous ameloblastoma was rendered. The average population in The Netherlands during this period amounted approximately 15 million people. Results: An annual incidence rate was approximately 1,5 per million population, the male-female ratio being 1.4: 1. The age at the time of diagnosis was 44.1 years. The average age in males was 46.3 years compared to an average age in females of 41.3 years, the difference being significant (p≤ 0.05). The results were compared with those available in only a small number of publications worldwide. Conclusions: There is no strong evidence for significant differences of the true incidence of ameloblastomas worldwide, neither for a gender predilection. The diagnosis is generally made at a somewhat lower age in women; this phenomenon is even much stronger in the Black population, irrespective of gender. No proper explanation for this finding can be provided. Key words:Odontogenic tumor, ameloblastoma, epidemiology.

Clinicopathological evaluation of 164 dental follicles and dentigerous cysts with emphasis on the presence of odontogenic epithelium in the connective tissue. The hypothesis of “focal ameloblastoma”

Objectives: Some ameloblastomas presumably originate from odontogenic epithelium within the connective tissue of dental follicles and dentigerous cysts. Therefore, it would seem reasonable to discuss as whether odontogenic epithelium proliferations, frankly displaying ameloblastomatous features (“focal ameloblastoma”), should be considered as an “early” ameloblastoma. Study Design: Histopathological reports from 164 dental follicles and dentigerous cysts from the Department of Oral and Maxillofacial Surgery/Oral Pathology of the VU Free University medical center in Amsterdam, The Ne-therlands, were reviewed. Histopathological slides from 39 cases reporting the presence of odontogenic epithelium within the connective tissue were re-evaluated in order to assess the possible presence of focal ameloblastomas. Results: Focal ameloblastomas were detected in one dental follicle and in two dentigerous cysts. During a follow-up period of 6, 8 and 22 years, respectively, no clinical signs of (recurrent) ameloblastoma have occurred in these patients. Conclusions: Focal ameloblastoma possibly represents the early stage of ameloblastoma development. Key words:Ameloblastoma, odontogenic epithelium, dentigerous cyst, dental follicle.