Cytomorphology of Hydatid Cyst: Comparison of Various Staining Techniques

Human echinococcosis (hydatidosis, or hydatid disease) is caused by the larval stages of cestodes (tapeworms) of the genus Echinococcus. The disease is extensively distributed worldwide. The diagnosis of hydatid cyst infection is established on clinical grounds along with radiological findings. However, specific diagnosis is based on microscopic examination of the cyst fluid and by demonstrating the different hydatid elements such as protoscolices, hooklets or fragments of laminated membrane. Thus, for better visualisation of these elements, various stains (Papanicolaou, May – Grunwald Geimsa (MGG), Hematoxylin and eosin (H & E), Masson’s trichrome (MT), Ziehl-Neelsen (ZN), Grams and PAS stains) were studied at our laboratory. Among these stains, Masson Trichome , Hematoxylin & Eosin, May – Grunwald Geimsa and Ziehl-Neelsen stains were more effective in staining and visualisation of the hydatid hooklets. We describe the cytologic features of a case of a hepatic hydatid cyst in a 70-year-old female patient where we conclude that due to the difficulty of staining and examining filter slides compared to sediment slides, we consider centrifugation preferable to filtration whenever the sample volume to be processed is suitable for the available centrifuge.