**4. Clinical presentation**

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

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, body scanning, surgery, or for other clinical reasons.

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 material and cystic membranes.
