**5. Diagnosis**

The combination of imaging and serology usually enables diagnosis. The standard diagnos‐ tic approach for cystic Echinococcosis is based on the clinical setting, imaging characteris‐ tics, predominantly ultrasonography, computed tomography (CT), X-ray examinations, and confirmation by detection of specific serum antibodies by immunodiagnostic tests.

In the detection of pulmonary echinococcosis very important role played by mass x-ray ex‐ amination of the population. It allows preventive examination at the present time to identify the disease before any clinical symptoms. Differential diagnosis of conduct between the echinococcus, tuberculoma, peripheral carcinoma, between the diseases, giving the spherical formation in the lungs. Use the full range of special methods except for the puncture. End of suspected unacceptable because of the possibility Echinococcus cyst rupture, risk of falling hydatid fluid in the pleura with the development of severe anaphylactoid reactions and col‐ onization by the parasite. (Fig 4a, Fig 4 b)

**◦ type IIc**: oval masses with scattered calcifications and occasional daughter cysts

Pulmonary hydatid disease (echinococcosis) does not present a constant clinical pattern, and consequently the clinical diagnosis tends to be inaccurate. As is so often the case, failure to think of the condition rather than lack of knowledge about it accounts for most of the mis‐ diagnoses. It would appear, therefore, of some value to re-emphasize certain of the features

Clinical manifestations varied widely depending on the status of the hydatid cyst. The most common presenting symptom of the patients was a cough, followed by chest pains of vary‐ ing severity. Clinical presentation of pulmonary hydatid cysts depends on the size of the cyst and whether the cyst is intact or ruptured. Intact cysts are either incidental findings or present with cough, dyspnea or chest pain. If it ruptures into a bronchus, pleural cavity or billiary tree it is called complicated cyst and may present with expectoration of cystic con‐ tents, productive cough, repetitive hemoptysis, fever or anaphylactic shock in addition.

Patients come to the clinician's attention for different reasons, such as when a large cyst has some mechanical effect on organ function or rupture of a cyst causes acute hypersensitivity reactions. The cyst may also be discovered accidentally during radiographic examination,

Physical findings are hepatomegaly when associated with liver involvement, a palpable mass if on the surface of the liver or other organs, and abdominal distention. If cysts in the lung rupture into the bronchi, intense cough may develop, followed by vomiting of hydatid

The combination of imaging and serology usually enables diagnosis. The standard diagnos‐ tic approach for cystic Echinococcosis is based on the clinical setting, imaging characteris‐ tics, predominantly ultrasonography, computed tomography (CT), X-ray examinations, and

In the detection of pulmonary echinococcosis very important role played by mass x-ray ex‐ amination of the population. It allows preventive examination at the present time to identify the disease before any clinical symptoms. Differential diagnosis of conduct between the echinococcus, tuberculoma, peripheral carcinoma, between the diseases, giving the spherical formation in the lungs. Use the full range of special methods except for the puncture. End of

confirmation by detection of specific serum antibodies by immunodiagnostic tests.

of hydatid disease, more particularly from the radiological point of view.

**• type III**: calcified cyst (dead cyst)

198 Principles and Practice of Cardiothoracic Surgery

**4. Clinical presentation**

**• type IV**: complicated cyst : e.g. ruptures cyst

body scanning, surgery, or for other clinical reasons.

material and cystic membranes.

**5. Diagnosis**

**Figure 4.** (a) Chest radiograph demonstrates multiple peripheral round areas of soft-tissue opacity.(b) CT scan shows a clearly defined capsule with a relatively hypo attenuating center, a finding that reflects the cystic nature of the lesions.

Bronchoscopy is unnecessary in patients with a typical clinical and radiological picture but it can be performed for differential diagnosis in cases of atypical radiological appearance [5, 6]. When bronchoscopy was performed in thoracic hydatidosis, pathologic findings were re‐ vealed in 70%. Bronchoscopy detected a whitish endobronchial lesion imitating endobron‐ chial tuberculosis with a caseous lesion. (Fig 5)

**Figure 5.** Flexible bronchoscopic image in a 42-year-old man with hemoptysis showing a white gelatinous membranelike structure protruding from the medial basal segment of the right lower lobe; CMAJ (with permission)

When a cyst becomes infected or ruptures, the clinical and radiological profile can mimic diseases such as nonresolving pneumonia, tuberculosis, and abscess or tumor of the lungs. Direct bronchoscopic visualization with biopsy allowed to quickly clarifying the diagnosis, leading to effective treatment. On the other hand, one should bear in mind the possibility that carcinoma may rarely have clinical, radiological, and serological features, similar to those of a hydatid disease. It is uncommon for the diagnosis to be made from the microscop‐ ic discovery of hooklets in respiratory secretions, highlighting the value of close liaison with microbiological staff.

#### **5.1. Laboratory tests**

Most serodiagnostic techniques have been evaluated for diagnosis of cystic hydatid dis‐ ease caused by Echinococcus granulosus. Formerly, the laboratory diagnosis of echinococ‐ cosis has been based chiefly on the results of the Casoni intradermal (ID) or the complement-fixation (CF) test. The CF test has a limited sensitivity, while the ID test may be unreliable since, once acquired, skin sensitivity may persist for life. After, the findings of Garabedian et al and Kagan et al [7,8] reported that indirect haemagglutina‐ tion (IHA) was more sensitive to formers tests but there were some limitations with the practical aspect of IHA, for example false positive reactions with other helminthic infec‐ tions, cancers and chronic immune complex disease.

Actually, the most sensitive technique in detecting pulmonary hydatid disease is immu‐ noglobulin G enzyme-linked immunosorbent assay (ELISA) test, with a sensitivity of 85.3%; it's a quantitative serodiagnostic method that specific IgG ELISA kit was available commercially. It was a better test for initial screening of suspected cases of human hyda‐ tidosis and was more acceptable due to its higher sensitivity and simplicity in practice [9]. Our data showed that ELISA is more sensitive than IHA for initial screening of sus‐ pected cases of hydatidosis.

**Figure 6.** Chest radiograph showing large hydatid cyst right upper lobe causing mediastinal shift to opposite side

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If the hydatid cyst is infected or ruptured, the radiological appearance may become atypical

Complicated, a variety of signs denoting different appearances of the hydatid cysts have been described. During enlargement, the cyst can erode into the bronchus and air can enter

between the pericyst and endocyst leading to the thin crescent (meniscus) sign (fig 9)

**Figure 7.** CT appearance of an uncomplicated giant hydatid cyst of the right lung.

and it may cause incorrect and delayed diagnosis.

Serological tests are often helpful, but measurable immunological responses do not develop in some patients, essentially in lung hydatid cyst contrary to liver localization, where it seems that it has more supply antigenic stimuli to host tissues. Laboratory testing should be used either in highly suspicious cases or for postoperative follow-up of pulmonary hydatid cyst disease. Antibody production is elevated during the first 4 - 6 weeks after surgical inter‐ vention, followed by a decrease during the next 12 - 18 months. In patients who have a re‐ currence before 2 years, antibody production remains similar to pre-operative levels [8, 9]. Eosinophilia is 10-30% positive in hydatid cyst disease. Eosinophilia increases if cyst rupture and it is also high in countries where parasitosis is endemic [10].
