Körner's septum (petrosquamosal lamina): the anatomical variant or clinical problem?

Körner's septum (KS) or petrosquamosal lamina is a bony lamina beginning at the articular fossa, extending above the middle ear, and running inferiorly and laterally to the facial nerve canal as it proceeds to the mastoid apex. This septum marks the junction of petrous and squamous bones. The paper presents details of the anatomical structure of KS, which is most often present at the level of the head of the malleus and/or the anterior semicircular canal. Attention is paid to embryological aspects of temporal bone development that lead to the formation of KS. Two imaging techniques most frequently used to diagnose KS are described, high resolution computed tomography (HRCT) and cone-beam computed tomography. Also presented is a case report of a 6-year-old patient suffering from chronic otitis media who developed a cholesteatoma due to presence of KS, illustrated with HRCT images and intraoperative capture. The authors describe diagnostic difficulties associated with this anatomical variant in the middle ear. The article also discusses the more frequent occurrence of this clinical problem in ears operated on due to chronic inflammation, retraction pocket or tympanosclerosis in comparison to healthy ears.

An algorithm for preoperative differential diagnostics of parotid tumours on the basis of their dynamic and diffusion-weighted magnetic resonance images: a retrospective analysis of 158 cases.

BACKGROUND: To verify the usefulness of a new algorithm for preoperative differential diagnostics of parotid tumours on the basis of their dynamic and diffusion- -weighted magnetic resonance imaging (MRI). MATERIALS AND METHODS: The retrospective analysis included 158 consecutive surgical patients with parotid tumours. Aside from ultrasound-guided fine needle biopsy, the protocol of preoperative evaluation included dynamic and diffusion-weighted MRI. According to the new diagnostic algorithm, the result of fine needle biopsy was considered only in the case of lesions with time to peak enhancement (Tpeak) > 60 s and washout rate (WR) ≤ 30% on dynamic MRI and apparent diffusion coefficient (ADC) ≤ 1.7 × 103 mm/s2 on diffusion-weighted MRI, or those presenting with concomitant lymphadenopathy. The accuracy of this algorithm was verified against final histopathological diagnoses. RESULTS: The new algorithm gave 10 true positive and 2 false positive results, as well as 132 and 14 true and false negative results, respectively. Its sensitivity and specificity (41.7% and 98.5%, respectively) were the same as in the case of fine needle biopsy alone. None of the 59 tumours that were qualified as benign solely on the basis of preoperative MRI turned out to be malignant on postoperative histopathological examination. CONCLUSIONS: Interpreted together, dynamic and diffusion-weighted MRIs provide the same accuracy in preoperative differential diagnostics of parotid tumours as fine needle biopsy. This substantiates the use of diagnostic algorithms in which biopsy would serve mostly as a secondary test to verify selected ambiguous radiological diagnoses. (Folia Morphol 2018; 77, 1: 29-35).

Bilateral large vestibular aqueduct syndrome in an 11-year-old boy. Radiological and clinical findings.

Clinical observations supplemented with imaging examination show that the large vestibular aqueduct syndrome (LVAS) is a rare developmental anomaly of the inner ear, which leads to hearing loss. The authors present a case history, results of imaging examination (high resolution CT, MRI), results of hearing acuity examinations (tonal audiometry, otoacoustic emissions, brainstem auditory evoked potentials) and results of balance examinations (videonystagmography) in an 11-year-old boy suffering from deep mixed progressive hearing loss of the right ear due to head trauma. The aim of this paper is to specify the most typical clinical, radiological and anatomopathological manifestations of this pathology of the inner ear. The authors describe the diagnostic and identification difficulties associated with the mixed hearing loss observed in this case. The article also discusses the child's activity limitations, which should be taken into account once diagnosis of this rare labyrinthine pathology is established.