Answer for CoW 22 Oct 2017
PULMONARY HYDATID CYST
Findings
Large relatively well circumscribed radiolucent cystic lesion is noted occupying almost the entire right hemithorax. MRI revealed septations and few daughter cysts It extends upto the right subphrenic region with compression of the superior border of the liver as well. The right main bronchus is compressed and anteriorly displaced by the lesion. These features are consistent with Hydatid cyst.
Discussion
Hydatid disease is a manifestation of larval infestation by the echinococcus tapeworm, common in various endemic regions. In adults, the lungs are second-most common organ to be involved by hematogenous dissemination Uncomplicated hydatid cyst appears as a well-defined homogenous radio-opacity on a chest X-ray Cysts can assume polycyclic configuration due to pressure from adjacent structures. Notching can also occur in cysts, giving them a bilobed appearance. The loss of a spherical shape on an X-ray with the appearance of small depression (resulting in a reniform shape) indicates bronchial rupture and is termed the “slot sign” Calcification is very rare in pulmonary hydatid cysts Hydatid cysts can erode a bronchus with air between the pericyst and the endocyst ,appearing as a radiolucent rim around the cyst on an X-ray known as the “crescent sign” With the introduction of more air, the endocyst shrinks and ruptures with the introduction of air into the endocyst. At this stage, an air fluid level is seen in the endocyst with a radiolucent rim between the pericyst and the endocyst, termed the “cumbo sign” or the “double arch sign” With further collapse of the endocyst, the membranes floating in the remaining fluid are known as the “water lily sign” or the “camolette sign”. With the rupture of the endocyst, daughter cysts may appear as round radio-opacities at the bottom of cysts, giving them a “rising sun” appearance. With coughing out of membranes, the pericyst can become empty (the “dry cyst sign”), appearing as air-filled cysts on X-rays.
Findings
Large relatively well circumscribed radiolucent cystic lesion is noted occupying almost the entire right hemithorax. MRI revealed septations and few daughter cysts It extends upto the right subphrenic region with compression of the superior border of the liver as well. The right main bronchus is compressed and anteriorly displaced by the lesion. These features are consistent with Hydatid cyst.
Discussion
Hydatid disease is a manifestation of larval infestation by the echinococcus tapeworm, common in various endemic regions. In adults, the lungs are second-most common organ to be involved by hematogenous dissemination Uncomplicated hydatid cyst appears as a well-defined homogenous radio-opacity on a chest X-ray Cysts can assume polycyclic configuration due to pressure from adjacent structures. Notching can also occur in cysts, giving them a bilobed appearance. The loss of a spherical shape on an X-ray with the appearance of small depression (resulting in a reniform shape) indicates bronchial rupture and is termed the “slot sign” Calcification is very rare in pulmonary hydatid cysts Hydatid cysts can erode a bronchus with air between the pericyst and the endocyst ,appearing as a radiolucent rim around the cyst on an X-ray known as the “crescent sign” With the introduction of more air, the endocyst shrinks and ruptures with the introduction of air into the endocyst. At this stage, an air fluid level is seen in the endocyst with a radiolucent rim between the pericyst and the endocyst, termed the “cumbo sign” or the “double arch sign” With further collapse of the endocyst, the membranes floating in the remaining fluid are known as the “water lily sign” or the “camolette sign”. With the rupture of the endocyst, daughter cysts may appear as round radio-opacities at the bottom of cysts, giving them a “rising sun” appearance. With coughing out of membranes, the pericyst can become empty (the “dry cyst sign”), appearing as air-filled cysts on X-rays.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!