Evaluation of radiologic diagnostic criteria and treatment options in skeletal muscle hydatid cysts

Aim: To investigate the diagnosis and treatment methods of soft tissue involvement of hydatid cysts (HCs). Materials and Methods: Eleven patients who were diagnosed as having HC with muscular tissue (soft tissue) involvement between 2010 and 2016 were evaluated retrospectively. Seven patients had typical HC magnetic resonance imaging (MRI) and four patients had cysts with an unusual appearance. We evaluated how to diagnose the cysts using imaging methods, their characteristic radiologic images, and treatment alternatives against the disease. The patients were treated with antihelminthic chemotherapy preoperatively and postoperatively. Results: Of the 11 patients who underwent treatment, 7 were diagnosed using MRI and 4 were diagnosed with histopathologic examinations. The mean follow-up period was 16 (range, 6–24) months, and the mean age was 39.4 (range, 24–56) years. In seven patients, multivesicular appearance with specific MRI findings, T2-hypointense rim appearance, double-rim sign, membrane dissociation, and appearance of daughter cysts were identified as diagnostic criteria. Two patients underwent ultrasound assisted percutaneous aspiration–injection–reaspiration (PAIR) treatment. Seven patients underwent total pericystectomy, and two patients underwent subtotal pericystectomy with serum saline injection into the cyst. Two patients showed signs of mild anaphylaxis, one during the diagnosis and one during treatment. Conclusion: There may be difficulties in the diagnosis and treatment of HCs of the musculoskeletal system. It should be known that there are alternative methods in the treatment (cyst excision and PAIR treatment). Clinical, serologic, and radiologic findings should be used in the diagnosis. To avoid complications during the histopathologic diagnosis, MRI should be examined in detail. It is thought that atypical cysts can be diagnosed (double-layer appearance and peripheral rim sign) in addition to typical cysts (detached membrane and multivesicular appearance), and diagnosis and treatment can be planned without anaphylactic complications.