Case presentation
A 17-year-old male presented to the emergency department of Imam Reza hospital of Kermanshah province of Iran. He complained of fever, repetitive cough, dyspnea, and chest pain initiated a few hours prior to hospital admission. He did not report any respiratory symptoms before this. His past medical history or drug history was unremarkable. He denied cigarette or alcohol abuse, and previous exposure to pets. He worked on a vegetable farm with his family. His familial history was unremarkable.
On general examination he was febrile (T=38.5 degrees Celcius), His pulse rate was 120 beats/minute, his respiratory rate was 24, and his blood pressure was 110/70 mmHg. His oxygen saturation was 91% on room air. He was not in respiratory distress and did not use respiratory accessory muscles. On respiratory system examination, respiratory sounds were decreased on the right hemithorax. The rest of the clinical examination including the cardiovascular system and abdomen were within normal limits.
The results of laboratory tests on admission day were as follows: hemoglobin of 15.6 mg/dl, white blood cell count (WBC) 12.7 x103/mm3 (differential count: neutrophils 90%, lymphocytes 7%, monocytes 3%), platelet count 229 x103/mm3, creatinine 0.9 mg/dl, International normalized ratio (INR) 1, partial thromboplastin time (PTT) 28 seconds, lactate dehydrogenase (LDH) 622 IU/ml (normal:225-500 IU/ml), aspartate transaminase (AST) 62 IU/L (normal:5-40 IU/L), alanine transaminase (ALT) 97 IU/L (normal:5-40 IU/L), alkaline phosphatase (ALP) 123 U/L (normal:80-306 U/L), total bilirubin 0.7 mg/dL (normal:0.2-1.4 mg/dL), direct bilirubin 0.3 mg/dL (normal:0-0.4 mg/dL), erythrocyte sedimentation rate (ESR) 10 mm/hr, and C-reactive protein (CRP) was positive.
A chest computed tomography (CT) scan was performed and showed a large cavitary lesion on the middle lobe of the right lung which contained a large amount of air, and soft tissue resembling a membrane. The imaging findings were compatible with the hydatid cyst. Few ground glass opacities were observed in the lower lobe of the right lung suggesting rupture of hydatid cyst. The left lung had no pathologic lesion (Figure 1). Ultrasonography of the abdomen was normal.
He was hospitalized in the infectious disease ward for additional workup and treatment. Albendazole was administered 400mg twice a day. A high titer of IgM antibody against echinococcus granulosus was detected in his serum. A thoracic surgery consult was done and surgery for resection of the cyst was planned. On the third day of admission, his oxygen saturation decreased to 70%, and he developed severe respiratory distress. Body temperature was 41 degrees Celcius and blood pressure was 100/65 mmHg. He was intubated and transferred to the intensive care unit (ICU). A Chest CT scan was performed and revealed rupture of the cyst and diffuse ground glass opacities with centrilobular pattern in the field of both lungs (Figure 2).
Acute respiratory distress syndrome (ARDS) was suspected. Methylprednisolone 1gr daily was started for 3 days followed by dexamethasone 4mg three times a day intravenously. Broad-spectrum antibiotic therapy was started for suspected secondary bacterial infection. Oral albendazole was continued. Five days later his oxygen saturation decreased and pneumothorax was detected on the chest CT scan. Therefore, a chest tube was placed in the right pleural cavity (Figure 3). Two weeks later he was extubated, and his oxygen saturation remained within normal limits by receiving oxygen through a facial mask. The chest tube was removed. He was discharged in stable condition four weeks after hospital admission. Oral albendazole was continued, and he was referred to a thoracic surgeon. He underwent resection of the cyst and lobectomy of the right middle lobe two weeks after discharge with no complications.