Novel Radiologic Approaches for Cholesteatoma Detection: Implications for Endoscopic Ear Surgery.

Technological advancement in computed tomography (CT) and MRI has improved cholesteatoma detection rates considerably in the past decade. Accurately predicting disease location and extension is essential for staging, planning, and preoperative counseling, in particular in the newer approach of endoscopic ear surgery. Improved sensitivity and specificity of these radiological methods may allow the surgeon to confidently monitor patients, therefore avoiding unnecessary surgery. This article outlines recent advances in CT and MRI technology and advantages and disadvantages of the newer techniques. Emphasis on improving the feedback loop between the radiologist and surgeon will increase the accuracy of these new technologies.

Diagnostic and management considerations in incidental common peroneal intraneural haemangioma.

Intraneural haemangiomas are rare tumours that can affect peripheral nerves. We describe a case of a 10-year-old female with an incidental finding of a common peroneal nerve lesion following knee injury. MRI demonstrated avid heterogeneous enhancement and peri-lesional oedema, and an open biopsy was performed revealing haemangioma on histopathological analysis. The patient was managed with observation and remains intact at 24-month follow-up.

Molecular and clonal evolution in recurrent metastatic gliosarcoma.

We discuss the molecular evolution of gliosarcoma, a mesenchymal type of glioblastoma (GBM), using the case of a 37-yr-old woman who developed two recurrences and an extracranial metastasis. She was initially diagnosed with isocitrate dehydrogenase (IDH) wild-type gliosarcoma in the frontal lobe and treated with surgery followed by concurrent radiotherapy with temozolomide. Five months later the tumor recurred in the left frontal lobe, outside the initially resected area, and was treated with further surgery and radiotherapy. Six months later the patient developed a second left frontal recurrence and was again treated with surgery and radiotherapy. Six weeks later, further recurrence was observed in the brain and bone, and biopsy confirmed metastases in the pelvic bones. To understand the clonal relationships between the four tumor instances and the origin of metastasis, we performed whole-genome sequencing of the intracranial tumors and the tumor located in the right iliac bone. We compared their mutational and copy-number profiles and inferred the clonal phylogeny. The tumors harbored shared alterations in GBM driver genes, including mutations in TP53, NF1, and RB1, and CDKN2A deletion. Whole-genome doubling was identified in the first recurrence and the extracranial metastasis. Comparisons of the metastatic to intracranial tumors highlighted a high similarity in molecular profile but contrasting evidence regarding the origin of the metastasis. Subclonal reconstruction suggested a parallel evolution of the recurrent tumors, and that the metastatic tumor was largely derived from the first recurrence. We conclude that metastasis in glioma can be a late event in tumorigenesis.

Orbital Apex Syndrome in Pseudomonas Sinusitis After Functional Endoscopic Sinus Surgery.

Sinusitis complicated by orbital apex syndrome is rare. The majority of cases are due to mucormycosis in immunocompromised patients. The authors report a case of orbital apex syndrome secondary to Pseudomonas sinusitis. The patient was a 79-year-old Type 2 diabetic woman who underwent left-sided functional endoscopic sinus surgery. Three months postprocedure, she presented with a 3-week history of gradual vision loss and constant temporal headache on the ipsilateral side. Examination revealed light perception vision, a relative afferent pupillary defect, absent corneal reflex, and disc pallor. Imaging revealed opacification of the posterior ethmoidal air cells extending to involve the orbital apex. Urgent orbital and sinonasal decompression was performed. Intraoperative specimens grew Pseudomonas aeruginosa. The patient was treated with liposomal amphotericin B, posaconazole, and piperacillin/tazobactam. The patient recovered with no visual sequelae. Pseudomonas is an important mimicker to consider in sinusitis causing orbital apex syndrome, and it may occur following functional endoscopic sinus surgery.

Predicting patterns of failure in temporal lobe GBMs: possible implications on radiotherapy treatment portals.

BACKGROUND: Characterise patterns of failure of Temporal Lobe (TL) Glioblastoma (GBM) following treatment with relation to normal temporal lobe anatomy and neural pathways. METHODS: 335 GBM patients received radiotherapy between 03/2007 and 07/2014, 100 were located in TL. Site of initial tumour and subsequent relapse were subdivided into 5 local TL sites (anterior, lateral, medial, posterior and superior); 5 adjacent regional sites (occipital lobe, inferior frontal lobe, caudate/thalamus/internal/external capsules, fornix/ventricular trigone), and 5 distant failure sites (ventricles, contralateral hemisphere, brainstem, leptomeninges and spine). Extension along major neuroanatomical pathways at initial presentation and at first documented Magnetic Resonance Imaging (MRI) failure were categorised into anterior, superior, medial and posterior pathways. RESULTS: Of the 100 patients, 86 had radiological progress with a median survival of 17.3 months. At initial diagnosis, 74% of tumours were linked to one TL site and 94% were confined to the TL. 19% had neural pathway disease at initial pre-treatment MRI. At first recurrence locoregional site failure was 74%. 26% failed within distant sites and 53% patients were noted to have neural pathway involvement. Initial tumour location predicted for local site recurrence (p < 0.0001), regional site recurrence (p = 0.004) and neural pathway recurrence pattern (p = 0.005), but not for distant sites (p = 0.081). CONCLUSION: Most GBMs fail at local or adjacent regional sites. Many of the recurrences occurred in a predictable pattern within a local or regional site, unique to initial TL site with more than half involving neural pathways. Knowledge of tumour infiltration and failure may improve target definition and radiotherapy.

Utilizing 18F-fluoroethyltyrosine (FET) positron emission tomography (PET) to define suspected nonenhancing tumor for radiation therapy planning of glioblastoma.

AIM: The authors sought to evaluate the impact of 18F-fluoroethyltyrosine (FET) positron emission tomography (PET) on radiation therapy planning for patients diagnosed with glioblastoma (GBM) and the presence of suspected nonenhancing tumors compared with standard magnetic resonance imaging (MRI). METHODS AND MATERIALS: Patients with GBM and contrast-enhanced MRI scans showing regions suspicious of nonenhancing tumor underwent postoperative FET-PET before commencing radiation therapy. Two clinical target volumes (CTVs) were created using pre- and postoperative MRI: MRI fluid-attenuated inversion recovery (FLAIR) sequences (CTVFLAIR) and MRI contrast sequences with an expansion on the surgical cavity (CTVSx). FET-PET was used to create biological tumor volumes (BTVs) by encompassing FET-avid regions, forming BTVFLAIR and BTVSx. Volumetric analyses were conducted between CTVs and respective BTVs using Wilcoxon signed-rank tests. The volume increase with addition of FET was analyzed with respect to BTVFLAIR and BTVSx. Presence of focal gadolinium contrast enhancement within previously nonenhancing tumor or within the FET-avid region was noted on MRI scans at 1 and 3 months after radiation therapy. RESULTS: Twenty-six patients were identified retrospectively from our database, of whom 24 had demonstrable FET uptake. The median CTVFLAIR, CTVSx, BTVFLAIR, and BTVSx were 57.1 mL (range, 1.1-217.4), 83.6 mL (range, 27.2-275.8), 62.8 mL (range, 1.1-307.3), and 94.7 mL (range, 27.2-285.5), respectively. When FET-PET was used, there was a mean increase in volume of 26.8% from CTVFLAIR to BTVFLAIR and 20.6% from CTVSx to BTVSx. A statistically significant difference was noted on Wilcoxon signed-rank test when assessing volumetric change between CTVFLAIR and BTVFLAIR (P < .0001) and CTVSx and BTVSx (P < .0001). Six of 24 patients (25%) with FET avidity before radiation therapy showed focal gadolinium enhancement within the radiation therapy portal. CONCLUSIONS: FET-PET may help improve delineation of GBM in cases with a suspected nonenhancing component. This may result in improved radiation therapy target delineation and reduce the risk of potential geographical miss. SUMMARY: We investigated the impact of 18F-fluoroethyltyrosine (FET) positron emission tomography (PET) on radiation therapy planning for patients diagnosed with glioblastoma (GBM) and a suspected nonenhancing tumor compared with standard magnetic resonance imaging. We performed volumetric analyses between clinical target volumes and respective biological target volumes using Wilcoxon signed-rank tests. FET-PET may help improve delineation of GBM in cases with a suspected nonenhancing component and reduce the risk of potential geographical miss.

The enigma of solitary necrotic nodule of the liver.

BACKGROUND: Solitary necrotic nodule of the liver (SNNL) is a rare benign lesion with an uncertain aetiology. There are no typical diagnostic clinical or radiological features, and this lesion is usually detected incidentally during imaging for other purposes. METHODS: We describe the clinical and radiological findings in three patients with histologically confirmed SNNL. The pertinent presenting features were documented and subsequent serological testing for parasites was performed. RESULTS: All three patients underwent resection because it was not possible to exclude a solitary malignancy on preoperative imaging. All three nodules had a serpiginous shape with areas of necrosis that showed marked staining for eosinophil granules. However, no viable parasites were seen in any specimen. There were no specific radiological features that were present in all three patients. Two patients had travelled to areas where parasitic infections are endemic and one patient had an eosinophilia on presentation. The histopathological findings in conjunction with the clinical presentation suggest that SNNL may be parasitic in origin. CONCLUSION: The diagnosis of SNNL is usually made after surgical excision. A preoperative diagnosis is difficult to make even with the use of multiple imaging modalities. The clinical and histopathological findings described in our three patients suggest that a transient parasitic infection is likely to be the cause in many cases. A history of potential exposure to parasites and serological testing for an eosinophilia or parasitic antibodies may help make the diagnosis of SNNL without the need for resection.