Osteochondroma is a benign cartilaginous neoplasm and the most common benign tumor of bone. Osteochondromas occur primarily in the axial skeleton with a predilection for the distal femur, and relatively few cases occur in the head and neck region. The majority of cases of osteochondromas in the head and neck region affect the mandibular condyle, with fewer cases reported in the skull base and the neck. To our knowledge, there is no reported case of osteochondroma of the hyoid bone documented in the English literature. We thus report the first case of a hyoid bone osteochondroma, presenting as an asymptomatic mass in a young woman.

Purpose

AAPM Task Group 204 introduced size-specific dose estimates for pediatric and adult patients undergoing body CT examinations. This investigation extends that work to head CT exams by using Monte Carlo simulations to develop size-specific, scanner-independent CTDIvol-to-organ-dose conversion coefficients.

Methods

Using eight patient models from the GSF family of voxelized phantoms, dose to the brain and lens of the eye was estimated using Monte Carlo simulations of contiguous axial and helical scans for 64-slice multidetector CT scanners from four major manufacturers. For each patient model and scan mode, scanner-independent CTDIvol-to-organ-dose conversion coefficients were calculated by normalizing organ dose by scanner-specific 16 cm CTDIvol values and averaging across all scanners. Head size was measured using both geometric and attenuation-based size metrics. Head perimeter and effective diameter (ED), both geometric size metrics, were measured directly from the GSF data at the first slice superior to the eyes. Because the GSF models' pixel data are provided in terms of organ identification numbers instead of CT numbers, an indirect estimate of water equivalent diameter (WED), an attenuation-based size metric, was determined based on the relationships between WED and both ED and perimeter for a sample of patient data. Correlations between CTDIvol-to-organ-dose conversion coefficients and the various patient size metrics were then explored.

Results

The analysis of the patient data revealed a best-fit linear relationship (R(2) of 0.87) between ED and WED across a wide variety of patient sizes. Using this relationship along with ED determined from the GSF data, WED was estimated for each GSF model. An exponential relationship between CTDIvol normalized organ dose and WED was observed for both contiguous axial and helical scanning. For head perimeter and ED measured directly from the GSF data, an exponential relationship between CTDIvol normalized organ dose and patient size was also observed for each scan mode. For all patient size metrics and scan modes, R(2) of the exponential fits ranged from 0.92 to 0.93 and 0.73 to 0.85 for the brain and lens of the eye, respectively.

Conclusions

For all scan modes, strong correlation exists between CTDIvol normalized brain dose and both geometric and attenuation-based patient size metrics. A slightly lower correlation between CTDIvol normalized organ dose and patient size was observed for the lens of the eye. This may be due to the combination of the eye lens being a small peripheral organ and the presence of surface dose variation in both contiguous axial and helical scanning. Results indicate that robust estimates of patient-specific head CT dose may be provided using the size-specific, scanner-independent CTDIvol-to-organ-dose conversion coefficients described in this work.

The purpose of the current study was to assess the prevalence of cyst formation at the brain-tumor interface in olfactory neuroblastoma. We used the UCLA patient-based Pathology and Radiology Head and Neck Database (UPP&R HAND) to identify the largest patient cohort reported to date with imaging and pathology data. Eighteen of thirty-one patients (58.1%) had evidence of intracranial extension on MRI, while four (22.0%) demonstrated cyst formation at the brain-tumor interface. The extent of intracranial extension was by far the strongest predictor for intracranial cyst formation, regardless of Hyams tumor grade, using a binary logistics regression model (p = 0.002) and ROC curve analysis (AUC 94.6%). Cyst formation at the brain-tumor interface was an uncommon imaging finding, and tends to occur with a larger component of intracranial tumor extension.

INTRODUCTION:Uveal melanoma is a rare intraocular tumor with heterogeneous biological behavior, and additional noninvasive markers that may predict outcome are needed. Diffusion- and perfusion-weighted imaging may prove useful but have previously been limited in their ability to evaluate ocular tumors. Our purpose was to show the feasibility and potential value of a multiparametric (mp-) MRI protocol employing state of the art diffusion- and perfusion-weighted imaging techniques. METHODS:Sixteen patients with uveal melanoma were imaged with mp-MRI. Multishot readout-segmented echoplanar diffusion-weighted imaging, quantitative dynamic contrast-enhanced (DCE) MR perfusion imaging, and anatomic sequences were obtained. Regions of interest (ROIs) were drawn around tumors for calculation of apparent diffusion coefficient (ADC) and perfusion metrics (K (trans) , v e , k ep , and v p ). A generalized linear fit model was used to compare various MRI values with the American Joint Commission on Cancer (AJCC) tumor group and monosomy 3 status with significance set at P < 0.05. RESULTS:mp-MRI was performed successfully in all cases. MRI tumor height (mean [standard deviation]) was 6.5 mm (3.0). ROI volume was 278 mm(3) (222). ADC was 1.07 (0.27) × 10-3 mm(2)/s. DCE metrics were K (trans) 0.085/min (0.063), v e 0.060 (0.052), k ep 1.20/min (0.32), and v p 1.48 % (0.82). Patients with >33 % monosomy 3 had higher K (trans) and higher v e values than those with disomy 3 or ≤33 % monosomy (P < 0.01). There were no significant differences between ADC (P = 0.07), k ep (P = 0.37), and v p with respect to monosomy 3. CONCLUSION:mp-MRI for ocular tumor imaging using multishot EPI DWI and quantitative DCE perfusion is technically feasible. mp-MRI may help predict monosomy 3 in uveal melanoma.

Objectives/Hypotheses Functioning pituitary adenomas may produce endocrinopathies such as acromegaly and Cushing syndrome. Both conditions lead to characteristic anatomic variations as a result of hormonally induced abnormal soft tissue deposition. We evaluate the anatomic differences between acromegalics and Cushing disease patients and compare these dimensions to controls. Design Radiographic review of preoperative magnetic resonance images (MRI) of the pituitary gland. Setting Tertiary academic medical center. Participants Patients who underwent transnasal, transsphenoidal surgery for pituitary adenomas found to have acromegaly or pituitary Cushing between January 1, 2007 and September 1, 2015. A total of 15 patients with similar MRIs and no history of pituitary or sinonasal disease were selected as controls. Main Outcome Measures Dimensions assessed were intercarotid distance; carotid canal width; piriform aperture width; distance from the piriform aperture to the anterior face of the sphenoid; sphenoid sinus height, width, and length; angle from anterior nasal spine to anteroinferior face of sphenoid sinus; choanal height; and nasal cavity height at the level of the vertical segment of the middle turbinate. Sphenoid sinus pneumatization patterns were recorded. Results There were 30 acromegalics and 31 Cushing disease patients. When compared with controls, both acromegalics and Cushing disease patients had significantly wider piriform apertures and a longer distance from the piriform aperture to the anterior face of the sphenoid sinus (p < 0.05). Acromegalics had a significantly less acute angle (19 ± 3 degrees) from the anterior nasal spine to the sphenoid (p < 0.05). Cushing disease patients had significantly lower sphenoid sinus length and shorter nasal cavity height (p < 0.05). There were no differences in intercarotid distance or carotid canal width. Conclusions As acromegalics and Cushing disease patients have known anatomic variations, the skull base surgeon should be aware of these differences and adapt their techniques and approaches as needed.

Objectives/Hypotheses Functioning pituitary adenomas may produce endocrinopathies such as acromegaly and Cushing syndrome. Both conditions lead to characteristic anatomic variations as a result of hormonally induced abnormal soft tissue deposition. We evaluate the anatomic differences between acromegalics and Cushing disease patients and compare these dimensions to controls. Design Radiographic review of preoperative magnetic resonance images (MRI) of the pituitary gland. Setting Tertiary academic medical center. Participants Patients who underwent transnasal, transsphenoidal surgery for pituitary adenomas found to have acromegaly or pituitary Cushing between January 1, 2007 and September 1, 2015. A total of 15 patients with similar MRIs and no history of pituitary or sinonasal disease were selected as controls. Main Outcome Measures Dimensions assessed were intercarotid distance; carotid canal width; piriform aperture width; distance from the piriform aperture to the anterior face of the sphenoid; sphenoid sinus height, width, and length; angle from anterior nasal spine to anteroinferior face of sphenoid sinus; choanal height; and nasal cavity height at the level of the vertical segment of the middle turbinate. Sphenoid sinus pneumatization patterns were recorded. Results There were 30 acromegalics and 31 Cushing disease patients. When compared with controls, both acromegalics and Cushing disease patients had significantly wider piriform apertures and a longer distance from the piriform aperture to the anterior face of the sphenoid sinus (p < 0.05). Acromegalics had a significantly less acute angle (19 ± 3 degrees) from the anterior nasal spine to the sphenoid (p < 0.05). Cushing disease patients had significantly lower sphenoid sinus length and shorter nasal cavity height (p < 0.05). There were no differences in intercarotid distance or carotid canal width. Conclusions As acromegalics and Cushing disease patients have known anatomic variations, the skull base surgeon should be aware of these differences and adapt their techniques and approaches as needed.

Background

The recent addition of immunotherapy as a treatment modality to surgery and radiation has vastly improved disease control for patients with keratinocyte-derived carcinomas (KCs) that are incurable with local therapies alone. With the advent of immune checkpoint inhibitors (ICPis) in non-melanoma skin cancers comes diagnostic and therapeutic challenges when considering treatment strategies for patients presenting with clinical perineural invasion (cPNI) of locally advanced KC of the head and neck.

Objectives

We report four cases that convey the diagnostic and therapeutic complexity of managing patients with neuropathic symptoms from cutaneous neurotropic carcinomas of the head and neck. We also discuss an updated review regarding immunotherapies and perineural invasion within KC management.

Conclusion

Patients presenting with symptoms suspicious for cPNI warrant an expanded diagnostic evaluation to correlate neurological findings with neurotropic spread of disease. While nerve biopsies can be precarious in sensitive areas, a history of skin cancer and clinical presentation suggestive of neurotropism may be enough to pursue timely management in the form of surgery, radiation, and/or systemic therapy given each patient's individual priorities, comorbidities, and prognosis. When adding ICPi as a treatment modality for patients with disease not amenable to local therapies, the potential for immune-related adverse events must be considered. A multi-disciplinary review and approach to the management of patients with KC and cPNI is essential for obtaining optimal patient outcomes.