Imaging techniques such as ultrasonography and computed tomography are not always sufficient to diagnose parasitic cysts of internal organs. Fine-needle aspiration cytology has been used as a diagnostic tool for human echinococcosis since the late 1980s.1,2 This technique is usually performed under ultrasound guidance and is useful in the preoperative diagnosis of hydatid disease by showing the diagnostic hooklets and scolices in the aspiration fluid, which are pathognomonic for the cestode Echinococcus granulosus.3 Even in the absence of protoscolices and hooklets, laminated fragments suggestive of a laminated layer are usually identified on smears, indicating a possible diagnosis of hydatid disease.4 Fine-needle aspiration cytology is usually combined with tissue biopsy of the cyst wall, which may unequivocally establish the diagnosis.5 Das et al3 used FNAC for diagnosis of hydatid disease in 8 cases with cysts located in the abdomen or thorax. Fine-needle aspiration cytology was diagnostic for hydatid disease in 5 cases. For the remaining 3 cases, it was suggestive for hydatid disease since laminated cyst wall yielding a positive reaction was found with periodic acid–Schiff stain. Sinan et al6 have applied ultrasound imaging for the diagnosis of abdominal hydatid disease. With ultrasound examination, diagnosis of hydatid disease was established in 80% of cases (44 of 55). For the remaining 11 cases, they used ultrasound-guided FNAC, which established the correct diagnosis in all cases without causing any complications.
Safioleas M, Safioleas C, Misiakos EP. Why Fine-Needle Aspiration Cytology Is Not an Adequate Diagnostic Method for Liver Hydatid Cyst—Reply. Arch Surg. 2007;142(7):690-691. doi:10.1001/archsurg.142.7.690-b