Tumor pathology of the orbit

ACR Appropriateness Criteria® Orbital Imaging and Vision Loss-Child

Orbital disorders in children consist of varied pathologies affecting the orbits, orbital contents, visual pathway, and innervation of the extraocular or intraocular muscles. The underlying etiology of these disorders may be traumatic or nontraumatic. Presumed location of the lesion along with the additional findings, such as eye pain, swelling, exophthalmos/enophthalmos, erythema, conjunctival vascular dilatation, intraocular pressure, etc, help in determining if imaging is needed, modality of choice, and extent of coverage (orbits and/or head). Occasionally, clinical signs and symptoms may be nonspecific, and, in these cases, diagnostic imaging studies play a key role in depicting the nature and extent of the injury or disease. In this document, various clinical scenarios are discussed by which a child may present with an orbital or vision abnormality. Imaging studies that might be most appropriate (based on the best available evidence or expert consensus) in these clinical scenarios are also discussed. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Transorbital and endonasal resection of a rare orbital ectopic atypical meningioma

A female patient in her early 20s presented with increasing proptosis of her left eye over 2 months. She had no other signs of diplopia, pain or visual loss on initial presentation. Subsequent imaging of her orbits revealed a medial rectus tumour. A transorbital open biopsy of this tumour was non-diagnostic/inconclusive, hence a combined transorbital and endonasal resection of this tumour was performed. Histopathology of the resected tumour revealed an unusual inflammatory-rich spindle cell neoplasm, which was determined to be a primary orbital ectopic atypical meningioma. These tumours are exceedingly rare, with only case reports/series reported in the literature. Complete surgical resection with margins is the proposed treatment. The role of radiotherapy is still controversial. More studies are required to improve our knowledge of this condition.

Orbital and eyelid diseases: The next breakthrough in artificial intelligence?

Orbital and eyelid disorders affect normal visual functions and facial appearance, and precise oculoplastic and reconstructive surgeries are crucial. Artificial intelligence (AI) network models exhibit a remarkable ability to analyze large sets of medical images to locate lesions. Currently, AI-based technology can automatically diagnose and grade orbital and eyelid diseases, such as thyroid-associated ophthalmopathy (TAO), as well as measure eyelid morphological parameters based on external ocular photographs to assist surgical strategies. The various types of imaging data for orbital and eyelid diseases provide a large amount of training data for network models, which might be the next breakthrough in AI-related research. This paper retrospectively summarizes different imaging data aspects addressed in AI-related research on orbital and eyelid diseases, and discusses the advantages and limitations of this research field.

Differentiation of Malignant and Benign Orbital Space-Occupying Lesions Using Contrast-Enhanced Ultrasound: Added Value From a Time-Intensity Curve-Based Quantitative Analysis

OBJECTIVES

To evaluate the value of time-intensity curve (TIC) analysis of contrast-enhanced ultrasound (CEUS) signal to differentiate malignant from benign orbital space-occupying lesions.

METHODS

The CEUS signal of 111 patients with orbital space-occupying lesions was retrospectively analyzed using SonoLiver software. TIC-related parameters such as the arrival time (AT), rise time (RT), time to peak (TTP), maximum intensity (IMAX), mean transit time (mTT), slope of the increase (RS), and slope of the decrease (DS) were compared between the malignant and benign groups. Receiver operating characteristic (ROC) curve analysis was used to acquire the cutoff values of these parameters for differential diagnosis.

RESULTS

TIC patterns were characterized by fast increase and fast decrease in signal intensity in the malignant group, fast increase and a slow decrease in signal intensity in the benign group. The differences in the IMAX, RS, DS, mTT, TTP, and RT between the 2 groups were statistically significant (p <.01), while the difference in the AT were not (p = .672). ROC curve analysis showed that IMAX = 427.20, DS = 34.72, and mTT = 33.55 were the best cutoff values for differential diagnosis of malignant and benign space-occupying lesions. The accuracy rate of CEUS visual evaluation for differential diagnosis was 66.67% (74/111), while TIC quantitative analysis could effectively improve the accuracy to 89.19% (99/111).

CONCLUSIONS

TIC analysis can improve CEUS efficiency to differentiate malignant from benign orbital space-occupying lesions.

Can we use radiomics in ultrasound imaging? Impact of preprocessing on feature repeatability

PURPOSE

The purpose of this study was to assess the inter-slice radiomic feature repeatability in ultrasound imaging and the impact of preprocessing using intensity standardization and grey-level discretization to help improve radiomics reproducibility.

MATERIALS AND METHODS

This single-center study enrolled consecutive patients with an orbital lesion who underwent ultrasound examination of the orbit from December 2015 to July 2019. Two images per lesion were randomly assigned to two subsets. Radiomic features were extracted and inter-slice repeatability was assessed using the intraclass correlation coefficient (ICC) between the subsets. The impact of preprocessing on feature repeatability was assessed using image intensity standardization with or without outliers removal on whole images, bounding boxes or regions of interest (ROI), and fixed bin size or fixed bin number grey-level discretization. Number of inter-slice repeatable features (ICC ≥0.7) between methods was compared.

RESULTS

Eighty-eight patients (37 men, 51 women) with a mean age of 51.5 ± 17 (SD) years (range: 20-88 years) were enrolled. Without preprocessing, 29/101 features (28.7%) were repeatable between slices. The greatest number of repeatable features (41/101) was obtained using intensity standardization with outliers removal on the ROI and fixed bin size discretization. Standardization performed better with outliers removal than without (P < 0.001), and on ROIs than on native images (P < 0.001). Fixed bin size discretization performed better than fixed bin number (P = 0.008).

CONCLUSION

Radiomic features extracted from ultrasound images are impacted by the slice and preprocessing. The use of intensity standardization with outliers removal applied to the ROI and a fixed bin size grey-level discretization may improve feature repeatability.

RESULTS OF 15 YEARS OF COLLABORATION BETWEEN THE DEPARTMENTS OF OPHTHALMOLOGY AND STOMATOLOGY IN ONCOLOGICAL SURGERY OF THE ORBIT: A DIAGNOSTIC AND THERAPEUTIC APPROACH

AIM

To report an overview of the most frequent tumors of the orbit, suggest diagnostic approach and possible solution according to experience with own cohort of patients.

MATERIAL AND METHODS

From patients files from the Department of Ophthalmology and Department of Stomatology, First Medical Faculty, Charles University, and General Faculty Hospital in Prague, Czech Republic, there were selected patients, who underwent the surgery due to the suspicion of malignant development in the orbit during the period 2005 - 2019. From the surgical records we found information about 497 cases. At the Department of Stomatology, there were 282 surgeries under general anesthesia performed, and at the Department of Ophthalmology, there were 215 surgeries, mostly under local anesthesia performed.

RESULTS

The number of surgeries in men and women was equal; patients of all ages were present. The median of patients age operated on at the Department of Stomatology was 53 years, and at the Department of Ophthalmology 63 years. The most common primary benign tumor was the cavernous hemangioma (9 %), the most common non-tumorous expansion was the dermoid cyst (7 %); the most common malignant tumor was the lymphoma (17,5 %). The last mentioned tumor was the most common diagnosis in the whole cohort as well.

CONCLUSION

Our cohort of patients is comparable with large cohorts published in the literature concerning age and gender distributions. Differences in frequencies of some lesions may be explained by that our cohort includes patients after the surgery only. The malignant lymphoma is the most common diagnosis indicated to surgical procedure, mostly biopsy. Comparing the two cohorts from our departments 20 years apart, the malignant lymphoma remains the most common indication for surgery, but the incidence of adenomas and adenocarcinomas of the lacrimal gland decreased. It is not the goal of this paper to evaluate all possible orbital affections. Suggested surgical approaches are just recommendations according to years of experience; however, in some situations, to choose an individual surgical approach is necessary.

Thrombosed orbital varix with mild, spontaneously resolving symptoms

Orbital varices are abnormally enlarged, thin walled veins in direct connection with normal orbital vessels. Stooping, bending, coughing or straining increase the venous tension and in this way can cause symptoms, such as bulging of the eyes (proptosis), orbital pain, bleeding, intermittent double vision. Small varices are managed by observation while larger lesions may require surgery. In our case report we demonstrate the case of a 72-year-old female patient with right sided retro-orbital pressure sensation for weeks, and exophthalmos with blurred vision for 1 week. MR investigation proved the presence of a partially thrombosed orbital varix on the right side, and a smaller, non-thrombosed varix on the left side. Observation was agreed, and the symptoms resolved spontaneously after several weeks.

Orbital varix: rare cause of blepharospasm

Orbital varix (or varicose) is an exceptional pathology with poor clinical sign. The blepharospasm can be a revealing cause. The long-term risk is optic atrophy and blindness. Magnetic resonance imaging is the best diagnostic tools. The rise of lesion dimensions by Valsalva maneuvers and prone position is characteristic. We report the observation of a 42-year-old young man, consulting for a blepharospasm of the left eye evolving for two years. Imaging investigations made the diagnosis of orbital varicose.

[Orbital hemangiomas: capabilities of modern neuroradiological diagnostics]

MATERIAL AND METHODS

In the period from 2010 to 2016. 14 patients with cavernous hemangioma (CH) and 2 patients with capillary hemangioma (CapH) of the orbit were examined. The age of CH patients varied from 17 to 67 years (median, 53 years); 8 females and 6 males. The age of CapH patients was 35 and 54 years. All patients underwent surgery with subsequent histological verification. CT-perfusion was performed in 10 CH patients and 2 CapH patients according to a developed low-dose protocol (80 kV, 200 mAs, t_scan=40 s) with allowance for a target localizer (80 kV, 120 mAs) and at a maximum radiation dose of not more than 4.0 mZv. Neoplasm microcirculation was quantitatively assessed by calculating hemodynamic parameters: blood flow velocity (BFV), blood volume (BV), and mean transit time (MTT). MRI without and with contrast enhancement was performed in 11 CH patients and 2 CapH patients according to the ophthalmologic protocol (Signa GE, 3.0 T) accepted at the Institute: without contrast enhancement - T1, T2, and T2-FLAIR modes, T1 and T2 with a Fat Sat technique at a scan thickness of 3 mm, and DWI MRI; contrast enhancement - T1 (three projections) mode, including the Fat Sat technique. SWAN (n=2) and non-contrast MR perfusion ASL (n=3) were also used. Diffusion-weighted images (DWI) were processed with calculation of the apparent diffusion coefficient (ACD).

RESULTS

In all CH patients, CT-perfusion revealed low perfusion parameters of blood flow: BV_CH=0.86±0.37 mL/100 g, BFV_CH= 4.89±2.01 mL/100 g/min with a high mean transit time MTT_CH=10.13±3.05 s compared to the same parameters of blood flow in the normal white matter: CBV_NormWM=1.63±2.22 mL/100 g, CBFV_NormWM=9.72±3.13 mL/100 g/min, and MTT_NormWM=6.76±2.78 s. In CapH cases, significantly increased blood flow velocity and volume values and a low MTT value in the tumor were observed: BV_CapH=10.30±4.10 mL/100 g, BFV_CapH=119.72±53.13 mL/100 g/min, and MTT_CapH=4.35±1.79 s. In the case of orbital hemangiomas, optimal MRI modes were T1 and T2 with the Fat Sat technique, a scan thickness of 3 mm, and intravenous contrast enhancement. The revealed pattern of contrast agent accumulation by CH, initially in the central part and then in the periphery, may be a useful radiographic sign in the differential diagnosis with other orbital tumors.

CONCLUSION

Modern CT- and MRI-based diagnostics of orbital hemangiomas provides not only the exact location, size, and spread of the lesion but also reveals the characteristic structural features of these tumors, and the use of perfusion techniques visualizes hemodynamics of the tumors. CT-perfusion-based hemodynamic parameters of cavernous hemangiomas typical of this type of hemangiomas may be used in the differential diagnosis with other tumors of this location. The use of contrast enhancement and the Fat Sat technique with a scan thickness of not more than 3 mm is optimal for MRI diagnostics of orbital hemangiomas.

Combining midfacial degloving, LeFort-I osteotomy and inferiorly extended lateral orbitotomy (Krönlein) for removal of an orbital cavernous haemangioma: a new approach

Orbital tumours, located in the medial extraconal and intraconal compartment of the orbit, represent a challenge, with regard to surgical exposure. In the present paper removal of a cavernous haemangioma, located in the medial intraconal compartment was accomplished by combining lateral orbitotomy, midfacial degloving and LeFort-I osteotomy. Resection of the tumour could be performed under direct vision. Surgical exposure and removal of the lesion were obtained, without causing damage to surrounding tissues. Aesthetical results and postoperative eye function proved to be highly satisfactorily. With regard to limitations, concerning the combination of these methods, extended surgery duration and invasiveness have to be named. According to the technical feasibility and postoperative results, this new surgical approach represents a reliable and fully viable alternative method for the removal of medial orbital tumours.

[Imaging of orbital tumors in children]

Orbital tumors in children are characterised by a wide histological diversity due to the architectural complexity of the orbit. Several classifications may be proposed according to their location, histologic type and malignant or benign character. The most common clinical manifestation is the leukocoria. Diagnostic delay of these tumors, even if they are benign, may affect prognosis and lead to a loss of vision and/or a morphological deformation. Imaging plays an important role in positive diagnosis, in the differentiation between benign processes and potentially malignant processes, in the assessment of local and loco-regional staging and in follow-up monitoring under treatment. This study aimed to highlight the radiological features of primary intra-orbital tumors in children which are, in general, different from those of adults, by conducting a retrospective study of 40 medical records whose data were collected in the Division of Pediatric Radiology at the Mohammed VI University Hospital in Marrakech, Morocco over a period of 4 years (2014-2017).

Optic Nerve Meningioma Mimicking Cavernous Hemangioma

A 38-year-old woman presented with rapidly worsening, painless right monocular vision loss. An examination revealed a visual acuity of 1.4/10 and a central scotoma in the right eye. The orbital magnetic resonance imaging (MRI) showed a well-delineated ovoid intraconal mass of the right eye, hyperintense on T2-weighted MRI with homogenous enhancement after contrast injection. The mass abutted and displaced the optic nerve. A diagnosis of cavernous hemangioma was evoked, which is the most common benign adult orbital mass with these MRI features. A biopsy was performed, and the histopathologic examination yielded a diagnosis of optic nerve sheath meningioma based on a positive antiprogesterone receptor antibody immunostaining. Our case highlights the problem with establishing a specific pathologic diagnosis based on MRI alone, even though the morphologic aspect is evocative. It is recommended to always conduct a histopathologic examination before establishing a specific diagnosis as pathology remains the gold standard, especially when the course of action or treatment may change, as in our case.

Automated tru-cut imaging-guided core needle biopsy of canine orbital neoplasia. A prospective feasibility study

The purpose of this study was to evaluate the diagnostic value of imaging-guided core needle biopsy for canine orbital mass diagnosis. A second excisional biopsy obtained during surgery or necropsy was used as the reference standard. A prospective feasibility study was conducted in 23 canine orbital masses at a single centre. A complete ophthalmic examination was always followed by orbital ultrasound and computed tomography (CT) examination of the head. All masses were sampled with the patient still on the CT table using ultrasound (US) guided automatic tru-cut device. The most suitable sampling approach to the orbit was chosen each time based on the CT image analysis. One of the following different approaches was used: trans-orbital, trans-conjunctival or trans-masseteric. In all cases, the imaging-guided biopsy provided a sufficient amount of tissue for the histopathological diagnosis, which concurred with the biopsies obtained using the excisional technique. CT examination was essential for morphological diagnosis and provided detailed topographic information that allowed us to choose the safest orbital approach for the biopsy. US guided automatic tru-cut biopsy based on CT images, performed with patient still on the CT table, resulted in a minimally invasive, relatively easy, and accurate diagnostic procedure in dogs with orbital masses.

Orbital tumours and tumour-like lesions: exploring the armamentarium of multiparametric imaging

Although the orbit is a small anatomical space, the wide range of structures present within it are often the site of origin of various tumours and tumour-like conditions, both in adults and children. Cross-sectional imaging is mandatory for the detection, characterization, and mapping of these lesions. This review focuses on multiparametric imaging of orbital tumours. Each tumour is reviewed in relation to its clinical presentation, compartmental location, imaging characteristics, and its histological features. We herein describe orbital tumours as lesions of the globe (retinoblastoma, uveal melanoma), optic nerve sheath complex (meningioma, optic nerve glioma), conal-intraconal compartment (hemangioma), extraconal compartment (dermoid/epidermoid, lacrimal gland tumours, lymphoma, rhabdomysarcoma), and bone and sinus compartment (fibrous dysplasia). Lesions without any typical compartmental localization and those with multi-compartment involvement (veno-lymphatic malformation, plexiform neurofibroma, idiopathic orbital pseudotumour, IgG4 related disease, metastases) are also reviewed. We discuss the role of advanced imaging techniques, such as MR diffusion-weighted imaging (DWI), diffusion tensor imaging, fluoro-2-deoxy-D-glucose positron emission tomography CT (FDG-PET CT), and positron emission tomography MRI (MRI PET) as problem-solving tools in the evaluation of those orbital masses that present with non-specific morphologic imaging findings. Main messages/Teaching points • A compartment-based approach is essential for the diagnosis of orbital tumours. • CT and MRI play a key role in the work-up of orbital tumours. • DWI, PET CT, and MRI PET are complementary tools to solve diagnostic dilemmas. • Awareness of salient imaging pearls and diagnostic pitfalls avoids interpretation errors.

Optimized imaging of the midface and orbits

A variety of imaging techniques are available for imaging the midface and orbits. This review article describes the different imaging techniques based on the recent literature and discusses their impact on clinical routine imaging. Imaging protocols are presented for different diseases and the different imaging modalities.