Rahul Mehta

Subjective and objective findings in patients with true dehiscence versus thin bone over the superior semicircular canal.

Objective To compare subjective and objective findings between patients with true dehiscence versus thin bone over the superior semicircular canal (SSC). Study design Retrospective case series. Setting Tertiary referral center. Patients All patients from our institution with true dehiscence or thin bone over the SSC on computed tomography temporal bone (oblique view) from 2007 to 2013. Main outcome measures Subjective test: Dizziness Handicap Inventory (DHI). Objective tests: Infrared video eye recording with varying stimuli (Tulio, Fistula, and Vibration); vestibular evoked myogenic potential (VEMP); electrocochleography; videonystagmography; pure-tone audiometry (i.e., air-bone gap). Results Fifty-four patients (64 ears) were reviewed. Thirty-nine patients (47 ears) had true dehiscence of the SSC on temporal bone computed tomography. Fifteen patients (17 ears) had thin bone over the SSC. There was no statistical difference in DHI scores for patients with true dehiscence versus those with thin bone over the SSC. Only cervical VEMP and air-bone gap via pure-tone audiometry revealed a significant difference between the two groups. The remaining vestibular assessments did not demonstrate any difference. No significant correlations were revealed between DHI and objective test findings across and within the two groups. Conclusion Among the objective tests, cervical VEMP and pure-tone audiometry are the only tools to distinguish between true dehiscence and thin bone over the SSC. DHI does not differentiate between these two groups. Furthermore, no correlation exists between DHI and any objective finding. Further investigation is necessary to develop a validated subjective symptom index of patients with SSC syndrome.

Sinonasal Neoplasms Involving the Cranial Base and Orbit: A Case Series of Unusual Pathology and Review of the Literature

1. Wenig BM. Undifferentiated malignant neoplasms of the sinonasal tract. Arch Pathol Lab Med. 2009; 133: 699-712 2. Gu X, Eskandari F, Fowler M. Sphenoid sinus basaloid squamous cell carcinoma presenting as a sellar mass: report a case with review of the literature. Head Neck Pathol. 2011; 5: 81-85 3. Vasudev P, Boutross-Tadross O, Radhi J. Basaloid squamous cell carcinoma: two case reports. Cases J. 2009; 2: 9351 4. Miyagi Maeshima A, Taniguchi H, Makita S, et al. Histopathological characteristics of lymphomas in the upper aerodigestive tract: a single institute study in Japan. J Clin Exp Hematop. 2015; 55: 7-11 5. Honsra D, Montague N, Stefanovic A, et al. Oral and extraoral plasmablastic lymphoma: similarities and differences in clinicopathologic characteristics. Am J Clin Pathol. 2010; 134: 710-9 6. Clifton N, Harrison L, Bradley PJ, et al. Malignant melanoma of nasal cavity and paranasal sinuses: report of 24 cases and literature review. J Laryngol Otol. 2011; 125: 479-485 7. Castillo JJ, Bibas M, Miranda RN. The biology and treatment of plasmablastic lymphoma. Blood. 2015; 125: 2323-30 References A total of 16 cases were reviewed, and 4 patients were selected given their uncommon diagnoses and therapeutic challenges. These included malignant mucosal melanoma, sinonasal undifferentiated carcinoma (SNUC), plasmablastic lymphoma, and basaloid squamous cell carcinoma. Their histopathologic appearance, IHC profile, and unique diagnostic characteristics are presented and reviewed. Treatment modalities consisted of surgery, radiation, chemotherapy, or a combination thereof. The literature review encompasses previous reports with a focus on histopathology and IHC in establishing a diagnosis. Treatment options are also reviewed for these rare neoplasms. Introduction

Is MRI Equal to CT in the Evaluation of Thin and Dehiscent Superior Semicircular Canals

Objective: Can magnetic resonance imaging (MRI) diagnose abnormally thin and dehiscent superior semicircular canals (SSCs) that traditionally rely on evaluation by computed tomography (CT) imaging? Study Design: Retrospective clinical study. Setting: Tertiary referral center. Patients: Adults who underwent both MRI and CT of the temporal bones over the past 3 years. Interventions: CT and MR images of SSCs were separately reviewed, in a blinded fashion by three neuroradiologists at our institution. CT diagnosis of abnormally thin or dehiscent SSC was used as the “gold” standard. Main Outcome Measures: 1) Dehiscent SSC. 2) Abnormally thin SSC. 3) Normal SSC. Results: One hundred temporal bones with evaluable superior semicircular canals from 51 patients were eligible for review on CT and MR imaging. There were 26 patients of thin SSC and 17 patients of SSC dehiscence on CT imaging, of which 13 and 15 respectively were also found on MRI. There were nine false-positive dehiscent SSC patients and four thin SSC patients observed on MR imaging while not observed on CT. For thin SSCs, MRI sensitivity was 61.9% and specificity of 94.3% with a positive predictive value of 81.3% and a negative predictive value of 86.2%. For dehiscent SSCs, sensitivity was 88.2% and specificity of 89.2% with a positive predictive value of 62.5% and a negative predictive value of 97.4%. Conclusion: In this series, MRI in the axial and coronal plane had a high negative predicative value for thin SSC (86%) and dehiscent SSC (97%). However, MRI cannot conclusively diagnose thin or dehiscent SSCs.

Magnetic Resonance Imaging versus Computed Tomography in Temporal Bone Carcinoma: Radiological and Pathological Correlation

Objectives: Correlate the findings of preoperative magnetic resonance imaging (MRI) and computed tomography (CT) in temporal bone carcinoma with histopathological findings following lateral temporal bone resection. Methods: In this retrospective review, 11 cases of temporal bone carcinoma over the past 3 years were reviewed at our institution. Preoperative CT and MRI scans were systematically reviewed for tumor involvement in 10 anatomic areas involving and surrounding the temporal bone. These were compared with results found on final histopathology. Results: Among the 11 cases, 30 anatomic areas of tumor involvement identified on CT imaging were also found on MRI and confirmed on final histopathology. Two areas suggestive on tumor involvement on CT and MRI (parotid gland and regional lymph nodes) and 2 areas on MRI alone (mastoid antrum and middle ear) were negative on final histopathology. MRI did not change the preoperative clinical staging in any of the 11 cases, however, examination of the MRI in 1 case suggested temporal lobe involvement that was not seen on CT images and subsequently changed the management of the patient. Conclusions: The addition of MRI in the preoperative evaluation of these patients confirmed the extent of tumor involvement seen on CT and did not identify additional tumor or facial nerve involvement in most cases except for one advanced case. In this case, the addition of the MRI findings changed the treatment plan. While CT remains the imaging gold-standard for preoperative evaluation and staging, MRI should be obtained in evaluating advanced temporal bone tumors.

Hydrophilic Hydroxyapatite Cement Cranioplasty: Preventing Cerebrospinal Fluid Leaks and Wound Complications in Translabyrinthine Acoustic Neuroma Surgery

Objectives: (1) Examine the efficacy of quick-setting, hydrophilic formulation of hydroxyapatite cement (HAC) used in cranioplasty for the prevention of cerebrospinal fluid (CSF) leaks and long-term wound complications following translabyrinthine acoustic neuroma (TLAN) surgery. (2) Review evolution of HAC cranioplasty. Methods: Retrospective case review from 2006 to 2013 in atertiary referral center. Consecutive patients undergoing translabyrinthine approach for acoustic neuroma tumors were operated on by the senior author. Intervention: Therapeutic: Cranioplasty combining a medial abdominal fat graft with hydrophilic hydroxyapatite cement filling the mastoid. Main outcome measures: Incidence of cerebrospinal fluid (CSF) leaks and any wound complications. Results: Forty-four patients met inclusion criteria. There were no CSF leaks or other wound complications in this series. Conclusions: Hydrophilic HAC appears to be safe and efficacious for cranioplasty following translabyrinthine acoustic neuroma surgery.