Subcutaneous Dirofilariasis of the Lateral Cervical Region: A Case Report.

Dirofilaria repens (D. repens)is an emerging zoonotic filarial parasite, increasingly implicated in human subcutaneous infections. While commonly presenting as solitary nodules in the ocular or facial regions, involvement of atypical anatomical sites remains rare and diagnostically challenging. We report a case of subcutaneous cervical D. repens infection in a 50-year-old woman from Greece with no history of travel or contact with animals. The patient presented with a firm, non-tender nodule over the sternocleidomastoid muscle. Ultrasound revealed a hypoechoic lesion with soft tissue involvement. Surgical excision revealed a cystic cavity containing a filamentous structure. Histopathological analysis demonstrated nematode larval sections with eosinophilic infiltration, and polymerase chain reaction (PCR) confirmed the presence of D. repens. The postoperative course was uneventful, and no antiparasitic therapy was required.  This case comes to enrich the reported cases of atypical D. repens presentations, highlighting the need for clinical awareness even among patients without classic exposure risks. Given its nonspecific clinical features, D. repens infection should be considered in the differential diagnosis of subcutaneous nodules, particularly when initial imaging and clinical evaluation do not align with neoplastic or inflammatory etiologies. Surgical excision remains both diagnostic and curative in most cases. Informed consent was obtained from the patient for publication.