Dirofilariasis involving the oral cavity: report of the first case from South America

Abstract

Oral dirofi lariasis is very rare with non-specifi c clinical manifestations. Here, we report the case of a 65-year-old South American woman with a submucosal nodule on her right buccal mucosa. The nodule was slightly tender and painful. Differential diagnoses included mesenchymal (lipoma or fi brolipoma, solitary fi brous tumor, and neurofi broma) or glandular benign tumors (pleomorphic adenoma) with secondary infections. We performed excisional biopsy. A histopathological examination revealed a dense fi brous capsule and a single female fi larial worm showing double uterus appearance, neural plaque, well-developed musculature and intestinal apparatus. Dirofi lariasis was diagnosed, and the patient was followed-up for 12 months without recurrence.

A Case Report on Oral Subcutaneous Dirofilariasis

“…Since the humans are a dead-end host, the nematode in humans does not reach sexual maturity and remains nonfertile. Consequently microfilaria are not released into the peripheral blood in humans and, due to the presence of an adult nematode in the subcutaneous tissue, chronic inflammatory infiltration can occur in the surrounding tissue forming a parasitic granuloma [ 1 , 2 , 7 , 9 ].…”

“…In the eyes it can cause detached retina, crystalline opacity, glaucoma, uveitis, episcleritis and limited loss of vision. Subcutaneous migration of parasite in tissues of head can cause trigeminal neuralgia [ 1 , 7 , 9 ].…”

“…Investigations like Giemsa stain and fine needle aspiration cytology followed by excisional biopsy are useful in confirming the diagnosis. Once the excision of the lesion is performed parasitological evaluation can be performed for the worm specimen [ 1 , 9 ].…”

Human oral dirofilariasis

“…Dogs and wild canides are the definitive hosts, humans are incidental hosts and acquire Dirofilaria when bitten by the female mosquitoes of the Culicidae family (genera Aedes, Culex , and Anopheles ). [1011] The deposition of hemolymph during a blood meal infects the host with the stage three larvae. In man, D. repens usually wanders in the subcutaneous tissues or produces a granulomatous nodule in the subcutaneous and sub-conjunctival tissues; intra-oral involvement is unusual.…”

Microfilaruria by Dirofilaria immitis in a dog: a rare clinical pathological finding

“…Dirofilariasis is a zoonotic disease with a high public health importance. It can be caused by D. immitis, D. repens, D. tenuis and D. ursi (Acha and Szyfres 2003;Da Silva and Langoni 2009;Pereira et al 2015), in which the first one is the most important for dogs (Acha and Szyfres 2003;Ambily and Usha 2012). It is frequent in all geographical regions from Brazil, mainly in the coastal States.…”