Skeletal muscle hydatid cysts presenting as soft tissue masses

Hippokratia 2010; 14 (2):126-130

NE. Gougoulias, SE. Varitimidis, KA. ` Bargiotas, TN. Dovas, G. Karydakis, ZH. Dailiana


Muscle hydatidosis is rare, accounting only for 3?5% of all cases. We present a case series of 9 patients (8 male, one female, mean age 59.3 years, range 48-75 years) with primary echinococcosis of skeletal muscles. The cysts presented as soft tissue masses in 8 patients, whereas in one, the cyst was an incidental finding on a CT scan performed for investigation of a lung problem. All hydatid cysts were confined into muscles, without affecting the bone. The location was the thigh region in 6 patients (quadriceps in 4, biceps in 2), the popliteal fossa (gastrocnemius) in one, the humerus (triceps branchii) in one and the shoulder (infraspinatus) in one patient. MRI showed multi vesicular cysts in all patients. Indirect hemagglutination serological test was positive in 6 out of 9 cases. En block surgical excision of the cysts was undertaken in all patients. Two patients received antihelminthic chemotherapy preoperatively. Histopathologic findings confirmed the diagnosis. No recurrence occurred during the follow-up period (1-8 years). Skeletal muscle echinococcosis should be considered in the differential diagnosis of limb masses, especially in endemic countries. A meticulous history taking and MRI imaging are essential, while pericystectomy is an effective method of treatment.