Intra‐oral Dirofilaria repens infection: report of seven cases

Abstract

Cutaneous dirofilariasis usually affects animals such as cats and dogs which are known to be the natural host of Dirofilaria. Dirofilariasis displays a worldwide distribution. Certain geographic regions account for the majority of reported cases. South-eastern United States, Australia and Europe have been identified as endemic regions (1, 2). However, new endemic areas are arising with increased awareness in African and Asian regions. Out of about 40 different species of Dirofilaria only a few species are commonly known to infect man, namely Dirofilaria immitus, D. tenices and D. repens. Human infection occurs when a human becomes a blood meal of an infected arthropod vector and on accidental entering of the worm. Rarely this zoonotic infection affects the oral mucosa (3). Man is the dead end of this parasite. Since the human body is an abnormal environment for the parasite, the development of the larvae is inhibited by means of retardation of sexual maturity. Lesions are presented as single non-tender subcutaneous nodules, and most patients are asymptomatic. Diagnosis is established by H&E sections prepared from excised nodules. In a majority of the cases, only a single worm either a male or a female could be identified. The worm is usually dead and degenerated with a massive inflammatory cell infiltration. Seven new cases presented as intra-oral nodules with their clinicopathological correlation are discussed.

Histopathological characterization of the oral lichenoid disease subtypes and the relation with the clinical data

“…A specific clinicopathological diagnostic protocol was complied for all cases following the criteria established by van der Meij and van der Waal (8) and Cortés et al (9). Based on these criteria, patients and biopsies were classified as follows: Clinically Typical (CT), Clinically Compatible (CC), Histopathologically Typical (HT) and Histopathologically Compatible (HC).…”

“…Presence, occasionally, of erosive-ulcerative, vesicular and/or plaque-like lesions. When any of these characteristics was absent, it was considered a CC case (8,9). …”

“…Typically, the clinical and histopathological assessments are required in all cases in order to perform a proper diagnosis of these disorders (6,8,9). An adequate clinical and histopathological analysis is crucial to reach a diagnosis and to assess the malignant potential of each case (2,6).…”

“…Most studies (2,7,10,11) agree, that the application of the WHO diagnostic criteria, modified by van der Meij and van der Waal in 2003 (8) for lichenoid processes, has proven to be inefficient in establishing a good correlation between the clinical and histopathological diagnosis, and to differentiate between oral lichen planus (OLP) and oral lichenoid lesions (OLL). Nonetheless, the study by Rad et al in 2009 (12), showed a good correlation between the clinical and the histopathological aspects.…”

“…(6,13,14). Moreover, the presence of epithelial dysplasia is a controversial datum in the histopathological analysis of these biopsies and, for some authors (6,8), it may even invalidate the diagnosis of oral lichen planus.…”