"Leave Me Alone" Lesions of Petrous Apex with Symptomatic Features

Introduction Pathologies of the petrous apex are rare and may remain silent for a long period of time or may manifest clinically with nonspecific signs and symptoms. Imaging plays a vital role in diagnosing and classifying the various appearances. The most described entities of the petrous apex frequently defined as anatomic variants or pseudolesions are retained fluid, marrow-filled petrous apex and cephalocele but these do not necessarily require intervention. Such kind of findings are confidently diagnosed as nonsurgical "leave-me-alone" lesions. Method 88 patients were admitted in the Otology Department over a 3-years period (2013 to 2016) with various auditory and vestibular complaints. Four of them aged from 35 to 65 years presented with symptoms as hemicrania, aural pressure, atypical positional vertigo, sudden hearing loss, Lermoyez vertigo and revealed abnormal findings on petrous bone imaging. The patients were assessed by MRI scan, audiometry, acoustic impedance and vestibular tests. Results Magnetic Resonance Imaging (MRI) scans showed various petrous apex appearances like unilateral trapped fluid, cephalocele or low pneumatization with fatty marrow. The questioned apex in the patients with fluid content showed mixed magnetic resonance (MR) signal characteristics (low to high T1 signal, high T2 signal). Fatty marrow apices reveal high intensity non-fat-saturated T1-weighted image and intermediate signal on non-fat-suppressed T2-weighted sequence. Conclusion The asymmetric bone fatty marrow and fluid accumulations can be found on MRI studies in patients with various audiological and vestibular symptoms, but also incidentally in patients with no complaints. These entities should be studied radiologically due to possibility of conversion into the spectrum of mucoceles and cholesterol granulomas. In some cases, petrous (pseudo) lesions can cause symptoms that require medical or surgical treatment.