Primary Giant Hydatid Cyst of Lumbar Paraspinal Muscles

Hydatid cyst disease, commonly caused by Echinococcus granulosus, rarely occurs in paraspinal muscles. Among the few reported cases, the current case is the largest paraspinal hydatid cyst disease ever reported in literature with a review of management of such large lesions.

A 38-year-old male presented with lower back swelling for 1 year. Ultrasonography and magnetic resonance imaging scans suggested hydatidosis, following which the patient was taken up for surgery after preoperative medical therapy. En bloc resection was done, and histopathologic examination of the resected specimen confirmed the diagnosis. Postoperative albendazole was also used, and no recurrence was noted at 24 months post operation.

Hydatid disease should be kept as one of the differential diagnoses for back swelling, especially in endemic regions. Giant-sized hydatid cysts of paraspinal muscles, though rare, cannot be ruled out on clinical ground alone. Thorough history taking and detailed examination should be aided with radiologic investigations like magnetic resonance imaging for an accurate diagnosis. En bloc excision of the cyst combined with preoperative and postoperative medical therapy is an effective method of treating this condition and significantly reducing complication rates.