Skeletal muscle hydatid cysts presenting as soft tissue masses

• Published in: Hippokratia Vol. 14; no. 2; pp. 126 - 130
• Main Authors: Gougoulias, N E, Varitimidis, S E, Bargiotas, K A, Dovas, T N, Karydakis, G, Dailiana, Z H
• Format: Journal Article
• Language: English
• Published: Greece LITHOGRAPHIA Antoniadis I.-Psarras Th. G.P 01.04.2010
• Subjects: Case Series; echinococcosis; hydatid cyst; skeletal muscle
• ISSN: 1108-4189; 1790-8019

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.