RESUMO
INTRODUCTION: Isolated parasitic swellings of the neck, particularly hydatid cysts, are rare, even in endemic countries. The aim of this study was to assess the epidemiological and clinical features and the diagnostic approach to head and neck hydatid disease. CASE REPORT: A 3-year-old boy was hospitalised for an isolated mass of the left side of the neck that had been gradually enlarging for one year. Neck ultrasound demonstrated a hypoechoic cystic structure on the lateral aspect of the neck, measuring 3.5cm in diameter. Histological examination of the surgical specimen confirmed the diagnosis of hydatid cyst. DISCUSSION: In endemic countries, a diagnosis of hydatid disease should be suspected in all cystic masses of the neck. Epidemiological, clinical, laboratory and radiological features can lead to a presumptive diagnosis of hydatid cyst and aspiration cytology can correct an erroneous diagnosis. Histological examination confirms the diagnosis in these unusual sites.