title: Olfactory colloid cyst.
abstract: Colloid cysts are rare intracerebral lesions that are predominantly located in the third ventricle. Extraventricular colloid cysts have only rarely been reported but so far there are no reports of a colloid cyst residing in the olfactory groove. A 74-year-old patient underwent a brain computed tomography scan for a mild head trauma that incidentally revealed a space-occupying lesion near the olfactory groove. Brain magnetic resonance imaging that ensued demonstrated a hyperintense lesion in T1, T2, and FLAIR sequences, without evidence of surrounding brain edema. To evaluate the metabolic status of the lesion, brain single-photon emission computed tomography with 99mTc-Tetrofosmin was then performed, revealing no tracer uptake, a finding consistent with benignity. Due to the diagnostic uncertainty the excision of the lesion was proposed. The patient underwent surgery and intraoperative a cyst was revealed. Furthermore the cyst seemed to erode the dura and due to its location there was an imminent danger for cerebrospinal fluid leak. Therefore a repair of the dura was performed and the cyst was excised totally. Histology verified the presence of a colloid cyst. Colloid cysts should be included in the differential diagnosis of lesions in the anterior fossa and although benign they may have an aggressive presentation by eroding the dura and producing CSF leak.
authors.affiliation: Department of Neurosurgery, University Hospital of Ioannina, Ioannina, Greece. alexiougrg@yahoo.gr
authors.forename: George A
authors.initials: GA
authors.lastname: Alexiou
authors.forename: Andreas
authors.initials: A
authors.lastname: Zigouris
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Pahaturidis
authors.forename: Ann
authors.initials: A
authors.lastname: Goussia
authors.forename: Spyridon
authors.initials: S
authors.lastname: Tsiouris
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Fotopoulos
authors.forename: Panayiota
authors.initials: P
authors.lastname: Zagorianakou
authors.forename: Spyridon
authors.initials: S
authors.lastname: Voulgaris
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002272:Carcinoembryonic Antigen / Q000032:analysis; D020863:Central Nervous System Cysts / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003102:Colloids; D035262:Cranial Fossa, Anterior / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D005625:Frontal Lobe / Q000473:pathology / Q000601:surgery; D006801:Humans; D033162:Incidental Findings; D007633:Keratins / Q000032:analysis; D008279:Magnetic Resonance Imaging; D008297:Male; D018396:Mucin-1 / Q000032:analysis; D019292:Skull Base Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed