Multilocular echinococcosis in humerus: a case report.

Hydatid cysts caused by E. multilocularis are less common than those caused by E. granulosus (Pintilie et al., 1996). Infection in the bones is rare, accounts to 0.9-2% of all hydatid cysts (Wirbel et al., 1997). A thirty-five-year old female was presented with a four month history of pain and swelling in her humerus. Plain radiography (Fig. 1) and ultrasonography revealed partial destruction of bone. Laboratory investigations revealed Hb, 15.2 gm, ESR, 11 1st hr and WBC, 10,000. Indirect haemagglutination test using hydatid antigen was positive (1/16,000) and ELISA (IgG) was positive (1/4096). Lung, liver and brain scans were normal. Endosteal-sarcoma was considered and a biopsy was performed. Histopathological examination of bone tissue, showed many cysts (Fig. 11). On surgical operation, a huge number of cysts were found, and removed. The patient was given Albendazole in the recommended dose (Mazyad et al., 1998), and followed up. Six months later, all symptoms and signs regressed. Again three months more, the serological levels markedly decreased and X ray was normal.