When the parasite strikes back: Secondary paraspinal hydatidosis: A case report.

introduction and importanceHydatid disease predominantly involves the liver and lungs, whereas intramuscular localization is exceedingly rare, particularly in the paraspinal region. CASE PRESENTATION: A 57-year-old man with surgically treated pulmonary and retroperitoneal hydatid cysts in childhood presented with chronic thoracolumbar and left intercostal radicular pain. Imaging showed a multiloculated cystic lesion in the left paravertebral muscles at D11-D12 and D12-L1 with extension into the corresponding neural foramina. He underwent surgical excision and histopathology confirmed Echinococcus granulosus infection. Postoperative management included albendazole therapy. At 18 months, MRI showed no recurrence, and the patient was asymptomatic with no radiologic disease. Given the risk of late relapse, long-term follow-up is planned. CLINICAL DISCUSSION: Muscular hydatidosis can present long after treated visceral disease. Diagnosis depends on clinical suspicion supported by serology and imaging, particularly in endemic regions. Definitive management is meticulous surgical excision with adjunctive antihelminthic therapy to minimize recurrence. Because primary muscular involvement is rare, misdiagnosis is common, necessitating heightened clinical vigilance. In our case, no recurrence was detected at 18 months. However, late relapse remains possible, warranting vigilant long-term surveillance with periodic imaging.

conclusionHydatid disease should be included in the differential for paravertebral masses, even after treated visceral disease. This case highlights the need for long-term surveillance and a multidisciplinary approach. Early recognition and appropriate therapy are essential to prevent complications and recurrence.