Pulmonary hydatid disease mimicking sequestration: differentiation on magnetic resonance imaging

Possible anaphylactic reaction due to pulmonary hydatid cyst rupture following blunt chest trauma: a case report and review of the literature

A hydatid cyst is a parasitic disease caused by the tapeworm Echinococcus granulosus. It is endemic in many areas, including New Zealand, Australia, and the Mediterranean region. Pulmonary hydatid disease can be diagnosed incidentally in asymptomatic patients or may cause symptoms such as cough, chest pain, dyspnea, fever, and hemoptysis both in patients with ruptured and nonruptured cysts. Anaphylactic reaction is a rare presentation of pulmonary hydatid cyst disease. In this case report, we report an unusual anaphylactic reaction following pulmonary hydatid cyst rupture secondary to blunt chest trauma.

Conservative management of a ruptured pulmonary hydatid cyst

Pulmonary hydatid cysts in children frequently develop complications such as infection and air leaks. Surgery combined with medical therapy remains the standard form of treatment. We report a 7-year-old child who developed rupture of a large pulmonary hydatid cyst following chest trauma; conservative management resulted in successful expulsion of the cyst.

Magnetic resonance imaging signal characteristics in hydatid cysts

The MRI features of hydatid cysts were retrospectively studied in 12 patients to look for specific signal characteristics. Twelve patients in the series included eight with abdominal, two with abdominal-pelvic, one with a sacral and one with a lung hydatid cyst. The T1-, T2- and proton density (PD)-weighted images of spin-echo sequence were used for imaging. The signal characteristics of the hydatid parent cyst capsule and fluid, daughter cyst fluid, detached germinal membrane and surrounding soft tissue reaction were noted. Observations revealed that the capsule is best seen on T2- and PD-weighted images. The daughter cysts are best demonstrated on T1-weighted images, whereas the difference in the signal intensities of parent cyst and daughter cyst fluid is better demonstrated on T2-weighted and T1-weighted images, and the detached germinal membrane is best seen on T2- and PD-weighted images. The signal characteristics of hydatid cyst morphology can help distinguish it from other entities.