Discussion
Currently, a clinical diagnosis of pulmonary hydatid is based on chronic
respiratory symptoms, supported by compatible radiologic findings and
hydatid serology. However, imaging findings in a complicated cyst can
overlap with lung abscess, tuberculosis, tumor, Wegener’s
granulomatosis, bronchiectasis, pneumothorax or empyema. Serology in
pulmonary haydatidosis has lower sensitivity than hepatic hydatidosis.
It can be false positive in other helminthic infections, cancer, chronic
immune disorders, liver cirrhosis, presence of anti P1 antibodies, etc;
and may be false negative if the cyst is unruptured3.
Thus it would be helpful if better diagnostic modalities are available.
There is no consensus regarding the place of bronchoscopy in diagnosis.
To the best of our knowledge, this is the first series reporting FFOB
under conscious sedation, in pediatric lung hydatid.
However, multiple reports in adult patients documented the unexpected
visualization of hydatid membranes during procedures performed for
persistent respiratory symptoms or radiological shadows. In a
retrospective analysis of 386 cases of lung hydatid, bronchoscopy
performed prior to surgery in 106 patients helped in establishing the
diagnosis in 21 patients4. In another retrospective
study of 72 patients with pulmonary hydatid, bronchoscopy performed in
34 patients showed cyst membranes in 7 patients5.
Other non-specific findings described by the authors included airway
hyperemia, edema, purulent secretions and extrinsic compression. The
relatively higher diagnostic yield in our series could be because most
children had complicated cysts.
Our experience suggests that FFOB with BAL (performed under conscious
sedation) could be an effective diagnostic modality, especially since
radiology findings or serology may be inconclusive even in suspected
cases. However, the procedure should be performed with great caution,
with preparedness for managing complications.