Intramuscular Hydatid Cyst of the Thigh: A Rare Presentation in an Elderly Patient.

ABSTRACT

Intramuscular hydatid cysts are an uncommon presentation of echinococcosis, with most cases occurring in the liver and lungs. This case report describes an 81-year-old male who presented with a painless, progressively enlarging swelling in the right thigh noticed over the past year. The patient's history included trauma to the area from an animal-related incident five years earlier. Physical examination revealed a firm, irregular, and non-tender mass. Ultrasonography suggested a multiloculated cystic lesion with calcification, raising suspicions of a hematoma or hydatid cyst. Fine-needle aspiration cytology indicated an organized hematoma with secondary calcification. Given the diagnostic uncertainty, surgical excision revealed a 3x3 cm hydatid cyst in the intramuscular plane. A histopathological examination confirmed the diagnosis. The patient's postoperative course was uneventful, with no signs of recurrence at the three-month follow-up. This case underscores the importance of considering hydatid disease in the differential diagnosis of intramuscular swellings, particularly in patients with relevant exposure histories.