Hyaluronic acid induced foreign body reaction mimicking neoplastic parotid cytology.

Masses near the angle of the mandible containing extracellular matrix or mucin on cytology raise concern for various benign and malignant parotid gland neoplasms. Here a 76-year-old female with a history of cosmetic hyaluronic acid (HA) filler injections presented with a painless 6 mm left sided facial mass. Injection of hyaluronidase into the mass had failed to cause regression, raising concern for a neoplastic process. Fine-needle aspiration (FNA) showed amorphous, mucinous/extracellular matrix-like material in a background of numerous histiocytes and occasional multinucleated giant cells, consistent with a foreign body giant cell reaction to HA. This uncommon reaction to HA filler creates previously unrecognized diagnostic pitfalls because of its resemblance on FNA to the extracellular matrix or mucin found in many salivary neoplasms.

Spinal cavernous malformations: magnetic resonance imaging and associated findings

<p><b>INTRODUCTION</b>We reviewed the clinical features, brain and spinal cord magnetic resonance (MR) imaging findings and associated abnormalities in six patients with spinal cavernous malformations (CMs).</p><p><b>METHODS</b>Lesions were defined on gradient-recalled echo (GRE) images but measured on T2-weighted images performed on 1.5- and 3-tesla clinical scanners.</p><p><b>RESULTS</b>Four patients had associated multiple cranial CMs and one patient had multiple spinal CMs. All spinal CMs were predominantly hypointense on GRE images, and most were predominantly hyperintense and surrounded by hypointense edge on T2-weighted images. Other associations included asymptomatic vertebral body and splenic haemangiomas.</p><p><b>CONCLUSION</b>We conclude that intramedullary spinal CMs typically have 'mulberry' or 'popcorn' appearances similar to those of cranial CM. The presence of associated haemangioma or familial cranial CM syndrome on MR imaging may suggest the correct diagnosis without requiring invasive investigations.</p>

Infections of the deep neck spaces

Deep neck infections (DNI) have a propensity to spread rapidly along the interconnected deep neck spaces and compromise the airway, cervical vessels and spinal canal. The value of imaging lies in delineating the anatomical extent of the disease process, identifying the source of infection and detecting complications. Its role in the identification and drainage of abscesses is well known. This paper pictorially illustrates infections of important deep neck spaces. The merits and drawbacks of imaging modalities used for assessment of DNI, the relevant anatomy and the possible sources of infection of each deep neck space are discussed. Certain imaging features that alter the management of DNI have been highlighted.

Multi-detector computer tomography angiography in the initial assessment of patients acutely suspected of having intracranial aneurysm rupture

<p><b>INTRODUCTION</b>Multi-detector computer tomography angiography (CTA) provides a fast non-invasive assessment of the cerebral vessels, is readily available in an acute setting and can potentially replace invasive digital subtraction angiography (DSA) for the diagnosis of intracranial vascular lesions in an emergency setting. We report our experience in the use of emergent cerebral CTA versus DSA in the assessment of patients presenting acutely with symptoms suspicious of brain aneurysm rupture.</p><p><b>MATERIALS AND METHODS</b>Thirty-seven consecutive patients presenting acutely with clinical suspicion of brain aneurysm rupture were evaluated over a 4-month period from January to April 2008. CTA with peripheral intravenous contrast injection was performed on a 32 slice helical scanner. DSA was performed within 48 hours for all cases when CTA was the initial assessment. Studies were assessed via radiology reports using DSA or surgery as the gold standard.</p><p><b>RESULTS</b>All except for 3 patients had CTA as the initial study. There were 26 cerebral aneurysms detected by CTA in these 37 patients, with 9 negative studies. There were 2 patients with arteriovenous malformations (AVM), 1 with AV fistula (AVF), 1 tumoral bleed, 2 vertebral dissections, and 1 missed sagittal sinus thrombosis (CVT) on CTA. Based solely on CTA assessment, 3 patients had direct surgical clipping of the aneurysm, while 4 proceeded to direct endovascular coiling.</p><p><b>CONCLUSION</b>Emergent CTA is a non-invasive, reliable and viable alternative to emergent DSA for the assessment of the cerebral vessels in the acute assessment of patients presenting with symptoms suspicious of brain aneurysm rupture. Where positive, it can serve as a guide to therapeutic decisions. Review of CTA source data is essential, especially for small lesions and for post-clipping assessment.</p>