Giant Hydatid Cyst Originating From Psoas Muscle Extending to the Iliac Bone: A Case Report

Hydatid cysts, caused by the Echinococcus granulosus parasite, predominantly affect the liver and lungs, but can also impact other organs such as the kidneys, brain, and muscles. Infection occurs when individuals ingest eggs from contaminated food or water, leading to cyst formation primarily in the liver. While hydatid cysts are commonly found in various endemic regions, muscular involvement is rare, particularly in the psoas muscle. This report presents a case of a muscular hydatid cyst, describes its management, and emphasizes the need for awareness and prompt intervention. A 50-year-old man presented with abdominal and left lower limb pain, along with weakness over several days. He was febrile, and a physical examination revealed pain during leg movement. Routine laboratory tests were normal. Ultrasound and computed tomography scans identified a solid cystic mass in the left lower quadrant, extending to the left lumbar muscle. After 28 days of preoperative albendazole therapy, the patient underwent surgery through a Rocky Davis incision, where a large hydatid cyst containing daughter cysts in the psoas muscle was discovered. The cyst was unroofed, and its contents were evacuated, followed by irrigation with hypertonic saline. Postoperative recovery was uneventful. He also received standard medication therapy with albendazole, and during monthly visits, no complications were observed during the one-year follow-up. This case contributes to the limited literature on muscular hydatid disease and highlights the importance of awareness among healthcare providers to ensure timely diagnosis and management.