Solitary echinococcal cyst, a rare cause of a round mass in the lung

History and admission findings: A 29-year-old man from Kazakhstan presented with right-sided chest pain, cough, whitish sputum and a temperature up to 38.5 degrees C. He had been working in an animal farm for the previous two years. Investigations: Laboratory tests showed increased inflammatory parameters ( WBC 15.9 gpt/l with an increased proportion of band and segmented granulocy tes, C-reactive protein (242.3 mg/dl). Chest radiogram showed an infiltrati on and effusion in the right base judged to be due to pneumonia. In additio n there was a round homogeneous mass, 2.5 cm in diameter, at the lateral th oracic wall in the 8(th) lower lobe segment. Computed tomography (CT) of th e lung and mediastinum confirmed these findings. Bronchoscopy, echocardiogr aphy, upper abdominal sonography and CT of the skull revealed no other spac e-occupying lesion. Diagnosis, treatment and course: The right-sided pneumonia was successfully treated, at first with ceftriaxone (i.v.), later with ofloxacin (by mouth) . An echinococcal cyst was considered especially because of the patient's p rofession in Kazakhstan in the differential diagnosis of the right-sided ro und mass and confirmed by an indirect haemagglutination test giving an anti body titre of 1:1024. In response a thoracotomy was performed and the mass, histologically an echinococcal cyst (E. granulosa), resected. There were n o other cysts, there was no explanation for the right-sided pneumonia. Conclusions: Even though Echinococcosis is rare in Central Europe, it shoul d be included in the differential diagnosis of a round pulmonary mass. A de tailed history, especially with regard to occupation and country of origin, is essential. Serological tests for specific Ecchinococcus antibodies, tog ether with usual imaging procedures, will usually and quickly provide the d iagnosis.