"Air bubble": a new diagnostic CT sign of perforated pulmonary hydatid cyst

Abstract

The greatest difficulty in the CT diagnosis of perforated pulmonary hydatid cyst (PPHC) is the increase in the attenuation numbers following infection. Because of the solid density of infected hydatid cysts, the differentiation from an abscess or neoplasm is usually impossible. The aim of this study was to evaluate the value of "air bubble" as a new CT sign in the diagnosis of PPHC. Sixty-five patients (28 men and 37 women) with PPHC were included in the study. As a control group, 55 patients who had malignant (n = 36) or non-malignant (n = 19) pulmonary diseases were also examined. Radiological diagnosis with classical CT findings was made in only 38 of 65 patients (58.5 %) with PPHC. Air bubble sign was positive in 54 of the patients with PPHC (sensitivity 83.1 %) but only 3 of 55 patients in control group (specificity 94.5 %). When we analyzed the CT scans with classical CT findings including air bubble, the diagnosis of PPHC was made in 61 of patients (93.8 %). It is concluded that "air bubble sign" is a valuable CT finding in the diagnosis of PPHC.

Spontaneous Expulsion of a Hydatid Cyst During Flexible Bronchoscopy

“…4 However, atypical features make the diagnosis difficult even when an associated cyst is present in the liver as seen in our case. 5 The value of flexible bronchoscopy in the diagnosis of a complicated pulmonary hydatid cyst has been highlighted by Saygi et al 6 Spontaneous expulsion of complete hydatid cyst during the procedure of bronchoscopy is a rare event and has not been reported in English literature. Follow-up of this patient reveals that she is free of any symptoms.…”

It′s easy to miss complicated hydatid cyst of lung

“…Köktürk O et al 12. and G. Yuncu et al ,[13] reviewed CT scan reports of a large number of patients with infected hydatid cyst that has been proven by other diagnostic methods including surgery.…”

“…Air-bubble sign has been included as a new CT sign indicating infected ruptured hydatid cyst. [1112] The mechanism of air bubble production is the dissection of air between the pericyst and parasitic membrane due to rupture or erosion of a bronchiole. [1415] Air bubble sign is best demonstrated in mediastinal window settings.…”

Unusual Radiologic Manifestations of the Echinococcus Infection in the Thorax

“…Complicated hydatid cyst may resemble many other pulmonary lesions and, rarely, carcinoma of the lung. 10 Treatment of pulmonary hydatid cyst is surgical, and we prefer cystotomy or cystotomy-capitonnage (as a parenchymapreserving method). However, if surgical treatment is delayed owing to earlier medical treatment of uncomplicated hydatid cyst, the cyst may rupture and suppurate.…”