Intracranial hydatidosis. Report of a case diagnosed on cerebrospinal fluid cytology

BACKGROUND: Hydatidosis occurs due to infestation with the larval stage of the Echinococcus species. Humans are incidental hosts. Symptoms and signs in humans are a slowly growing mass lesion, especially in the central nervous system. Diagnosis depends on the appropriate presentation and history with corroborative radiology and serology. Microscopic detection of characteristic parasitic scolices and hooklets is confirmatory. CASE: A 10-year-old girl presented with complaints of headaches and convulsions for the preceding several months. Computed tomography findings showed asymmetric dilatation of the right lateral ventricle by an intraventricular, focally calcified mass. The radiologic suspicion was an intraventricular tuberculoma, hydatid cyst or choroid plexus papilloma. Cytologic examination of cerebrospinal fluid (CSF) smears revealed characteristic echinococcal components. CONCLUSION: Intracranial hydatid cyst is a fairly uncommon manifestation of an echinococcal infestation and shares clinicoradiologic features with several intracranial, space-occupying lesions. Cytologic examination of CSF samples may be employed to detect confirmatory evidence of a clinical/radiologic suspicion.