A rare case of ruptured mediastinal echinococcal cyst causing diagnostic challenge: A case report

Echinococcus is a common infection in an endemic country like Bhutan. Mediastinal echinococcosis is rare. Although presentation due to a mediastinal echinococcal cyst is variable according to the cyst's location, a reaction due to rupture of the cyst and simultaneous reaction to an administration of antibiotics such as ceftriaxone can cause a diagnostic challenge. We present a rare case of a mediastinal echinococcal cyst that ruptured at the time of admission, causing a diagnostic challenge of the cause of the reaction.

A 54-year-old female patient presented with increasing shortness of breath, chest discomfort, and backache for a one-year duration. Computed chest tomography showed a cystic lesion in the right posterior mediastinum measuring 7.3 × 5.5 × 9.3 cm. The patient developed features of cyst rupture at the time of admission which was detected after the administration of antibiotics ceftriaxone to treat for suspected cyst infection. This caused a diagnostic challenge as the patient developed a reaction confusing the cause of the reaction.

Initially, an emergency chest x-ray showed the cyst rupture's features. An emergency right-sided chest tube drainage was placed. The patient underwent a right thoracotomy and peri-cystectomy with an uneventful post-operative recovery.

Any cystic lesion in the lung in an endemic region should prompt evaluation to rule out echinococcal cysts. Cyst rupture can occur suddenly and cause a reaction to the cyst fluid. Simultaneous antibiotic administration in a suspected cyst infection can miss a life-threatening ruptured echinococcal cyst, which is notorious for causing anaphylaxis.