[Primary hydatic cyst of the lung. Diagnostic problems (author's transl)].

Diagnosis of primary cystic disease of the lung is often difficult, and because of this, in non-endemic regions, patients are often referred to the surgeon with an erroneous diagnosis. Clinical signs are completely non-specific. The most common one is hemoptysis; X-rays often fail to confirm hydatic cyst because of the volume, topography, or rupture of the cyst. Biological tests are often of little help. Serological reactions are negative in over one-half of the cases. The advantage of other complementary examinations (bronchiography, bronchoscopy, angiography, echotomography, scintigraphy) including transparietal punctions of the cyst, are discussed in light of the literature.