The moving cervical mass: A surprising discovery

Human dirofilariasis is a rare zoonotic infection caused by filarial nematodes of the genus Dirofilaria, with Dirofilaria repens being the most common species affecting humans. Humans are accidental hosts, typically presenting with solitary subcutaneous nodules that can mimic other benign or malignant conditions. Cervical (neck) localization is particularly uncommon, making diagnosis challenging, especially in regions where the disease is rarely reported. We report the 23rd confirmed case of human dirofilariasis in Tunisia, occurring in a 72-year-old woman from a rural area who presented with a painless, mobile left lateral cervical mass evolving over 10 days. Ultrasonography revealed a small subcutaneous cystic lesion containing a mobile vermiform structure suggestive of parasitic infection. Laboratory investigations showed no eosinophilia or microfilaremia. Surgical excision of the lesion was performed. Parasitological examination demonstrated a filarial nematode with a multilayered, striated cuticle and prominent longitudinal ridges. Morphological features and reconstructed dimensions (approximately 10 cm in length and 450 μm in diameter) were highly suggestive of Dirofilaria repens. Postoperative recovery was uneventful, with no recurrence at three-month follow-up. Although rare, human subcutaneous dirofilariasis should be considered in the differential diagnosis of mobile, painless cervical masses in endemic or emerging areas. Surgical excision is curative, and increased clinical awareness is essential to ensure prompt diagnosis and appropriate management.