Disseminated Cystic Echinococcosis Cured With Lengthy Albendazole and Praziquantel Oral Therapy

To the Editors: A 12-year-old boy with ill-defined chest pain was referred to us due to a chest radiograph (Fig. A, A1) demonstrating several round lung lesions. The initial hemogram demonstrated eosinophils 1,060/μL. A serum test for antibodies against Echinococcus granulosus was positive. A computed tomography (CT) scan of the chest and abdomen demonstrated 5 cysts in the lungs (3 on the left), 10 smaller hepatic cysts, along with a single 22-mm cyst in the splenic hilum. Whole-body magnetic resonance imaging (MRI) confirmed the above lesions and showed an additional single 15-mm cyst on the right sacral bone. No cysts were detected inside the peritoneal cavity or brain. He was started on albendazole 400 mg per os bid with the goal of completing 3 monthly cycles with drug-free intervals of 14 days. During the first drug-free interval, he was readmitted because of right-sided thoracic pain. One month later, that is, again soon after albendazole was discontinued due to the prescribed treatment cycle, he returned with right-sided thoracic pain. Therefore, we received informed consent from the family and started daily oral therapy with albendazole 400 mg per os bid and praziquantel 600 mg per os 3 times per week for 2 months because the regional supply of praziquantel was limited. After the first 2 months of therapy, a generous supply of praziquantel was imported from Belgium by the family, and he completed 16 months of uninterrupted daily oral therapy with albendazole 400 mg bid along with praziquantel 600 mg bid. Both drugs were taken sequentially with fatty foods. Therapy was extremely well-tolerated, with absence of hematologic, hepatic, or other toxicity. Although ultrasonography is the method of choice for diagnosis, staging, and follow-up of cystic echinococcosis (CE) cysts, we used whole-body MRI and thoracic CT because of the disseminated nature of his disease with multiorgan involvement. Imaging studies confirmed the impressive response to medical therapy (Fig. A, A2, A3, B and D). The patient is now more than 3.5 years off therapy and continues to be in excellent health.FIGURE.: Sequential imaging of the patient’s disseminated CE. All transverse images are approximately at the same level. Dates of imaging are shown. A: Chest radiographs. A1: Initial chest radiograph reveals well-circumscribed cystic lesions throughout the lungs (black arrows), followed by gradual reduction in their number and size (A2–A5). B: Pulmonary CT scans. B1: Pulmonary cysts, B2: pulmonary cysts after 1 month of therapy. Note the characteristic water lily sign, also shown in A2. B3: Pulmonary cysts 1 year later. Note a residual small cyst on the left lung. B4: Barely recognizable pulmonary cyst with concomitant fibrotic elements, B5: complete radiologic healing. C: Abdominal MRI scans. C1: coronal view showing multiple hepatic and a single splenic cyst (arrow), C2: coronal T2WI after 2 years reveals substantial hepatic cyst reduction; the splenic cyst is now almost isointense to the splenic parenchyma, C3: coronal T2WI after 2 more years; barely identifiable hepatic lesions; the splenic lesion is hypointense to the splenic parenchyma. D: Pelvic MRI scans. D1: T2WI and D2: T1WI showing a right sacral cyst (white arrows). D3: T2WI and D4: T1WI of the sacral cyst; no lesion is identified. MRI indicates magnetic resonance imaging; T2WI, T2 weighted image; T1WI, T1 weighted image.In Europe, albendazole is licensed for interrupted treatment of CE, as described above, usually for a maximum of 3 cycles. However, the French Agency for the safety of medical and health products stresses that continuous treatment may be recommended in disseminated disease, since it achieves increased cyst nonviability with comparable toxicity with the interrupted regimen.1 Praziquantel, an effective drug against the intestinal stages of E. granulosus in carnivores, has been added to albendazole for combined treatment of CE and was found to substantially increase the serum concentrations of its active metabolite, albendazole sulfoxide.2 Praziquantel side effects are temporary and dose-related.3 Alvela-Suarez et al administered combination therapy in 57 patients with CE.4 Only 8 patients reported mild adverse effects, mostly gastrointestinal, followed by headaches and dysgeusia. Although cysts of CE which become inactive through treatment need close monitoring due to potential reactivation,5 the extended follow-up in our patient makes us feel confident that his disease will not relapse. Praziquantel deserves a randomized clinical trial of combination therapy versus albendazole monotherapy in patients with similar responsive cyst stages. However, steps must be taken to make praziquantel easily available and affordable in endemic countries.