A retrospective study on the coexistence of hydatid cyst and aspergillosis.

Objectives: Hydatid cyst is a zoonotic disease with an endemic regional distribution, and Aspergillus is a saprophytic fungus that may cause allergic pulmonary aspergillosis, aspergilloma, and semi-invasive and invasive aspergillosis. The coexistence of a saprophytic fungus and hydatid cyst is extremely rare. The aim of this retrospective study was to evaluate the coexistence of aspergillosis and echinococcosis in archival materials and to discuss its probable clinical significance.

Methods: Hematoxylin-eosin (HE)-stained sections of 100 archival cases with the diagnosis of hydatid cyst were reevaluated by four pathologists independently. Grocott's methenamine-silver (GMS) and periodic acid-Schiff (PAS) were applied to the slides that were suspected of having co-infection with Aspergillus to confirm the diagnosis.

Results: Two cases of aspergillosis and hydatid cyst coexistence were found out of the 100 reevaluated archival cases with a diagnosis of hydatid cyst. Both of the cases were located in the lung, in immunocompetent patients.

Conclusions: Aspergillosis and hydatid cyst coexistence may be important in patients with immune deficiency and in cases with pre- or perioperatively ruptured cysts. There are no reliable data on the specificity and sensitivity of radiological imaging techniques in detecting the existence of Aspergillus in hydatid cysts. Histopathological evaluation is essential for diagnosis and for the planning of management.