Abdominal cystic hydatid disease (CHD): classification of sonographic appearance and response to treatment.

The natural history of cystic hydatid disease (CHD) can be divided into two stages. The first is characterized by the proliferation of the parasite; the second is marked by involution, ie, when the hydatid undergoes spontaneous distress or is subjected to pharmacological treatment. Echography makes it possible to study this evolution and to evaluate the stages of this parasitic pathology. This study of the evolution of abdominal CHD in 81 patients suffering from 127 cysts, with or without Albendazole treatment suggests a new sonographic classification: type I: simple CHD; type II: multiple CHD, type III: with detachment of membrane CHD; type IV: mixed CHD, type V: heterogeneous CHD; type VI: hyperechogenic CHD; type VII calcified CHD. Forty-seven patients suffering from 90 cysts of types I, II, III, IV, and V were treated with Albendazole; 31, suffering from 34 CHD of types VI and VII, were not treated, as they were considered involutional; 3 patients with 3 cysts refused therapy. Albendazole treatment resulted in the disappearance of 9 and in the solidification of 62 cysts. Of the remaining cases of CHD, 10 cysts showed sonographic alterations and 5 showed no modifications. Surgery was necessary for 2 patients (4 cysts). This new classification seems to be an aid in the recognition of the natural and therapy-induced involution of CHD and seems to improve the evaluation of the efficaciousness of the therapy.