Imaging the External Ear: Practical Approach to Normal and Pathologic Conditions.

The external ear (EE) is an osseous-cartilaginous structure that extends from the auricle to the tympanic membrane. It is divided into two parts: the auricle (or pinna) and the external auditory canal (EAC). Given the ease of access to the EE, imaging studies are not always needed to make a diagnosis. However, when lesions block visual access to areas deep to the EE abnormality, complications are suspected, or there is lack of response to treatment, imaging becomes essential. A basic understanding of the embryologic development and knowledge of the anatomy of the auricle and EAC are useful for accurate diagnosis of EE lesions. Congenital, traumatic, inflammatory, neoplastic, and vascular conditions can affect the EE. An overview of the anatomy and embryologic development of the EE is presented, with discussion and illustrations of common and uncommon conditions that affect EE structures and a focus on the CT and MRI features that are of interest to radiologists. CT is usually the first diagnostic modality used to evaluate the EAC and is the superior method for demonstrating bone changes. MRI provides excellent tissue characterization and enables one to better define lesion extension and perineural tumor spread. In addition, a flowchart to facilitate the differential diagnosis of EE abnormalities is provided. Online supplemental material is available for this article. ©RSNA, 2022.

Primary Parotid Tumor Thrombosis: Immunohistologic Features and Awareness of Metastatic Potential.

Tumor thrombosis is a poor prognostic feature and an exceptionally rare occurrence in salivary gland malignancies. We present a case of primary parotid myoepithelial carcinoma (MC) with tumor thrombosis in the external jugular vein (EJV). An 82-year-old man presented with a right-sided facial mass. MRI with and without gadolinium demonstrated a mass of the right parotid gland with a filling defect of the right EJV. The patient underwent right parotidectomy and selective neck dissection. Tumor thrombosis was found intraoperatively within the EJV. Final pathology demonstrated a poorly differentiated MC. Adjuvant radiation therapy without concurrent systemic therapy was administered. Three months later, restaging positron emission tomography (PET) with CT revealed numerous bilateral pulmonary nodules with biopsy, demonstrating poorly differentiated MC without locoregional relapse. Given that primary parotid tumor thrombosis is associated with a poor prognosis, the use of early systemic therapy should be investigated.

Intractable Hiccups Due to Posterior Inferior Cerebellar Artery Aneurysm.

This is the third reported case of a posterior inferior cerebellar artery (PICA) aneurysm presenting as intractable hiccups (IH). A previously healthy 29-year-old woman was admitted with a 2-week history of hiccups occurring >100 times per minute. Symptoms persisted despite numerous noninvasive therapies. Magnetic resonance imaging and magnetic resonance angiogram of the brain showed a left PICA aneurysm that was confirmed by catheter angiography. Symptoms resolved following suboccipital craniotomy and resection. Although rare, PICA aneurysm is a potentially curable cause of IH.