Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Pulmonary paragonimiasis
- Radiologic Findings
- Fig. 1 Chest PA shows nodular increased opacity in left upper lung field.
Fig. 2-6 (Images taken after 2 weeks) Chest PA shows decrease in extent of previous nodular opacity in left upper lung field, but there is newly appeared increased opacity at left hilar region. Chest CT shows subpleural consolidation with peripheral ground-glass opacity and adjacent pleural effusion in left upper lobe apicoposterior segment, and another consolidation at the superior segment of left lower lobe with linear density extend to the pleural surface.
Fig. 6-10 (Images taken after 4 weeks of initial study) Chest CT shows decrease in extent of previous consolidation in left upper lobe apicoposterior segment, but increase in extent of consolidation at the superior segment of left lower lobe with newly appeared focal air-bubble.
Parasitic eggs were identified from the percutaneous needle biopsy.
- Brief Review
- Pulmonary paragonimiasis is a parasitic infection caused by trematodes (or lung flukes) of the genus Paragonimus. This disease is caused by ingestion of a raw or incompletely cooked freshwater crab or crayfish infected with the metacercaria. Paragonimus excyst in the small intestine, and the larvae penetrate the intestinal wall and enter the peritoneal space. Next they penetrate the diaphragm and pleura and enter the lung in 3–8 weeks, where they mature to adult flukes.
Patients with disease present with fever, chest pain, and respiratory symptoms such as chronic cough and hemoptysis. Diagnosis is confirmed through the detection of parasite eggs in the sputum, pleural fluid, or feces. In addition, the larvae can often be found via bronchial brushing. Intradermal and serologic tests are also available.
The common CT findings include pleural effusion, hydropneumothorax, pulmonary nodules or air-space consolidation, and cysts.
Radiologic findings correlate well with the stage of the disease. The penetration of juvenile worms through the diaphragm into the pleural cavity can cause pleural effusion or pneumothorax. Once the parasites reach the lung, patchy airspace consolidations can be observed, a phenomenon that reflects the presence of exudative or hemorrhagic pneumonia which can cavitate. Contrast-enhanced CT performed during this stage may show hypoattenuating fluid-filled cysts surrounded by hyperattenuating consolidation in the adjacent lung. Linear areas of increased opacity or hyperattenuation indicate peripheral atelectasis or worm migration. Worm cysts, whose diameters range from 0.5 to 1.5 cm, are better visualized after the consolidation resolves and manifest as either solitary or multiple nodules or gas-filled cysts depending on their content and their communication with the airway. Chest radiographic and CT findings include a ring shadow usually less than 3 mm thick and a crescent-shaped area of increased opacity or hyperattenuation within the cyst indicating that the worms have attached to the wall. Complications of cysts include pleural effusion, empyema, and pneumothorax.
- References
- 1. Im JG, Whang HY, Kim WS, et al. Pleuropulmonary paragonimiasis: radiologic findings in 71 patients. AJR 1992;15-:39-43.
2. Kim TS et al. Pleuropulmonary Paragonimiasis: CT Findings in 31 Pateints. AJR 2005; 185: 816-821
3. Henry Travis S. et al. Chest CT Features of North American Paragonimiasis. AJR 2012; 198: 1078-1083
- Please refer to
- Case 259 Case 295 Case 349 Case 409 Case 502 Case 527 Case 537 Case 585 Case 612 Case 676 Case 684 Case 715 Case 741 Case 828 Case 885 Case 909 Case 965 Case 1021
-
- Keywords
- Pulmonary Paragonimiasis, lung, Parasitic infection,