RESUMEN
Abstract: Zoonotic dirofilariasis infestation, caused by Dirofilaria Repens, is described worldwide in different countries. A 31-years-old male patient presented thoracic muscle pain after growth of an ovoidal undefine cyst in left parasternal region. Patient reported several contacts with different species of animals for a familiar activity. In absence of blood inflammatory indices and systemic symptoms, imaging studies showed a suspected muscle cyst infection. Surgical excision was performed and microbiology confirmed parasite nature. Dirofilaria Repens, probably adult female, was identified. Treatment resulted to be definitive and any other clinical and surgical approach was needed. Healing time was uneventful and follow-up showed no further systemic relapses. The case highlights the effectiveness of surgical treatment in this subcutaneous infestation for an increasing number of human cases reported in endemic areas such as Central Italy.