Unique case of Loa loa filariasis in a thyroid goiter reported in Switzerland

A. Miftaroski, A. Kühn, A. Meyer, J. Ducry, V. Erard, E. Fontana, B. Egger

Objective

Loa loa filariasis is an endemic parasitosis with geographical distribution in West Africa. Commonly known as the «African eye worm» it migrates in human subcutaneous tissues typically causing localized angioedema known as Calabar swellings. Occasionally the worm also crosses into the subconjunctival tissue (African eye worm) where it can be easily detected. Systematic dissemination is extremely rare.

Methods

We are presenting the case of a 56 years old African woman from Cameroon, living in Switzerland since 2010. She has been addressed for an evaluation of a nodular thyroid goiter increasing in size. In the setup of the regular diagnostic workshop a fine needle aspiration (FNA) was performed which surprisingly revealed a massive presence of the parasite Loa loa in the thyroid nodule. After a systemic eradication with Dietylcarbamazine(DTC) for several months the patient underwent a hemithyroidectomy. Surgery as well as postoperative follow-up was completely uneventful. No Loa loa microfilariasis could be proven any more at histological examination of the resected specimen.

Conclusion

This is a unique case reported in Switzerland, of a systemic dissemination of the Loa loa worm into the thyroid. A successful eradication has been performed by a DTC-treatment for several month which was followed by a surgical hemithyroidectomy. In the literature an increasing frequency of Loa loa filariasis in the western society is reported, which is most likely associated with the actually increasing emigration rate out of West Africa. Commonly eye symptoms and skin lesions are described. Atypical manifestations and symptoms due to a dissemination of the parasite into other organs, as found in our case, are described on extremely rare occasions.