Diagnosis of Hydatic Pulmonary Cyst

When x-rays were discovered in 1895 specialists started to describe the radiologic aspects of the pulmonary diseases. Levy-Dorn and Zadek affirmed that the characteristic picture of an entire simple cyst in the lungs is a round shadow with neat borders. As every symbol in biology, this affirmation proved to be false and so Lanari was able to say that the most perfect image of an hydatic cyst he had seen corresponded to a sarcoma. The studies continued and Claessen gave an important step in his treatise of hydatidosis. Later the works of Sergent, Beclere, Tuffier, Nemenow, Escudero, Deve, Belot, Lozano, Morquio, Petzetakis, Peuteuil, Stephani, Guarini, Liemann, Lagos Garcia, Queirolo and others made the problem of the diagnosis of hydatic cyst reach its full maturity. For a better study we shall make an anatomoradiologic division and thus find: A). Unbroken cysts: The density of the shadows on the roentgen picture is proportioned to the specific weight of the bodies that appear in itsince the specific weight of the whole cyst-its mother-bag, its two walls and the liquid it contains is greater than that of the surrounding air, hydatic cyst can be easily seen in the lungs. Tuffier asserted that x-rays can pass through the hydatic cyst without producing a shadow. Recently, Escardo and Anaya stated that an hydatic cyst smaller than an egg cannot be seen on the x-ray screen. We find both affirmations false, for reasons explained above and because we have seen simple, not calcified cysts as small as a cherry produce a picture and the vomica or the operation proved they were hydatic cysts. The difficulty of diagnosis consists in differentiating hydatic cysts from other bland parts of the same density, like tumors, infiammations, parasites etc. The resemblance of their shadows with those of hydatic cysts is the reason there are no pathognomonic images in hydatidosis of the lungs but only characteristic ones. The roentgenologic image of an unbroken simple cyst depends greatly upon its localization. Central cysts generally develop according to the law of Belot and Peuteuil which reads: Every neoformation in the lungs tends to adopt a spherical form because the density of the lung tissues is small and homogenous. There is no axis of expansion, for the forces of peripheral attraction of the lungs are equally distributed and influenced only by the changes of intrathoracic pressure due to respiration. In consequence, Beclere asserts that every hydatic cyst produces a round, dark, frequently spheric, homogenous shadow with neat borders, as if drawn with a compass, easily seen against the clarity of the surrounding parenchyma. This concept is widely accepted and supported by Holsknecht, Didie, Picort, Auspensky, Morquio etc., while others criticize it, particularly Escudero