RESUMO
INTRODUCTION AND IMPORTANCE: Hydatid cyst is a parasitic infection caused by Echinococcus granulosis. It mostly involves the liver and lungs; however, muscle involvement is an uncommon event. The diagnosis of such cystic masses is still a challenge due to the presence of more common pathological conditions in soft tissue. Imaging is useful and can identify a definitive diagnosis. CASE PRESENTATION: We present a case of a 32-year-old woman with history of close contact with dogs and cats, who complained of an isolated swelling in the right upper thigh growing gradually over a period of 3 years. Ultrasound reported intramuscular hydatid cyst in the right thigh. Hydatid cyst was completely excised. The outcome was good, with no recurrence in one year. CLINICAL DISCUSSION: Ultrasonography is an excellent and cost-effective imaging modality with a high negative predictive value in the evaluation of palpable superficial soft-tissue masses and hydatid cysts. CONCLUSION: Isolated intramuscular hydatid cyst is rarely reported, even in endemic areas of the disease, so the diagnosis should be considered in any cystic masses of soft tissue, particularly in subjects from high-endemic zones. Although the treatment of choice in such cases is surgical excision but prevention is more favorable to fight against hydatid disease.
