Lacrimal gland lesions: Can addition of diffusion-weighted MR imaging improve diagnostic accuracy in characterization?

Cutaneous squamous cell carcinoma radiographically mimicking infiltration into the lacrimal gland

Cutaneous squamous cell carcinoma (SCC) is a common malignancy of the skin, with the potential for local invasion and metastasis. Here, we present a case series of two patients with SCCs, suggesting radiological infiltration of the lacrimal gland on magnetic resonance imaging. However, histopathological examination revealed lymphoplasmacytic infiltration of the lacrimal gland consistent with dacryoadenitis, with no evidence of SCC infiltration. Our cases highlight the potential for peritumoural inflammation to cause dacryoadenitis and radiologically mimic tumour infiltration into the lacrimal gland.

Diffusion-Weighted Imaging of the Orbit: A Case Series and Systematic Review

PURPOSE

To describe the findings of diffusion-weighted imaging (DWI) for a series of orbital lesions and provide a systematic review of relevant literature.

METHODS

A retrospective review of 20 patients with orbital lesions who underwent MRI with DWI at two academic institutions between 2015 and 2020 was performed. Lesion diagnosis was histopathologically confirmed except a presumed cavernous hemangioma. Echoplanar diffusion-weighted images had been acquired using 2 or 3 b values (b=0 and 1000 or b=0, 500, and 1000) at 1.5T or 3T. Lesions with significant artifacts were excluded. DWI sequences were analyzed by neuro-radiologists blinded to the diagnosis. Mean ADC values of lesions were calculated from a single region of interest. An independent two-tailed t test was used to compare categories of lesions with p < 0.05 considered significant. A systematic review of the literature was performed.

RESULTS

Our study included 21 lesions. ADC values were significantly lower for malignant lesions (0.628 ± 0.125 × 10 -3 mm 2 /s) than inflammatory lesions (1.167 ± 0.381 × 10 -3 mm 2 /s) ( p < 0.001). ADC values were significantly lower for orbital lymphoma (mean 0.621 ± 0.147 × 10 -3 mm 2 /s) than idiopathic orbital inflammation (mean 1.188 ± 0.269 × 10 -3 mm 2 /s) with no overlap ( p < 0.001).

CONCLUSIONS

Orbital malignancies demonstrated lower ADC values, while inflammatory processes demonstrated higher ADC values, except IgG4-related disease. DWI and ADC values differentiated idiopathic orbital inflammation from orbital lymphoma. This study highlights the role of DWI in evaluating orbital pathology.

Radiopathological Correlation in Orbital Lesions

PURPOSE

The objective is to analyze the radiological diagnosis of orbital lesions and their correlation with the final histopathological findings. We compared the initial reports by extramural radiologists and an in-house radiologist specialized in orbital imaging to evaluate the diagnostic accuracy in the interpretation of orbital imaging.

METHODS

This was a retrospective chart review of forty patients referred to a Tertiary Eye Care Center in South India over a period of 7 years. These patients already had their imaging done elsewhere. The imaging was re-evaluated by an in-house radiologist. The radiological findings were correlated with the histopathological diagnosis. The diagnostic accuracy between the two radiologists was compared. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value in differentiating malignant from benign lesions were calculated in both groups. The sensitivity and PPV of the radiological diagnosis for neoplastic and inflammatory lesions in both groups were analyzed.

RESULTS

The accuracy in differentiating malignant from benign and inflammatory lesions by our in-house radiologist and extramural radiologists was 95% (κ = 0.9 [0.764, 0.997]) and 50% (κ = 0.036 [-0.160, 0.232]), respectively. The sensitivity and PPV of the radiological diagnosis by our in-house radiologist were 93.31% and 100% for benign lesions and 95.24% and 95.24% for malignant lesions. On the contrary, reports from the extramural radiologists showed a sensitivity and PPV of 76.92% and 66.67% for benign lesions and 14.28% and 60% for malignant lesions.

CONCLUSION

A high radiological diagnostic accuracy is possible when analyzed by radiologists experienced in orbital imaging.

Lacrimal Gland Lesions Biopsied in a Tertiary Eye Center in Saudi Arabia: A Clinical, Radiological, Surgical, and Histological Review

Purpose

To study the demographics and clinical presentation of biopsied lacrimal gland lesions in a tertiary eye center and determine the accuracy of radiological imaging and blood investigations in reaching the diagnosis. We also studied the histopathological outcome of different lacrimal gland biopsy approaches.

Materials and Methods

A retrospective review of patients’ charts from 2014 to 2021 who underwent lacrimal gland biopsy. The data collected included demographics, clinical presentations, surgical approaches used, blood workup done, and histopathological and radiological diagnoses. The accuracy of radiological imaging in diagnosing lacrimal gland pathologies was evaluated by comparing radiological interpretation to the final pathological report.

Results

In a total of 48 cases, the most common lacrimal gland lesion was nonspecific inflammation of the lacrimal gland (34%, n=17) followed by lymphoproliferative lesions (25%, n=12). Females (62.5%, n=30) were more affected than males (37.5%, n=18). Other lesions included pleomorphic adenoma, angiolymphoid hyperplasia with eosinophilia, and IgG4 disease. Complete blood investigations were performed in 45.8% of patients and a systemic disease was found in only 18.2%. The initial assumptive diagnosis based on MRI and CT scan images was congruous with the histopathological diagnosis in 42% and 12%, respectively. Three surgical approaches were used for incisional biopsy in this study, including sub-periosteal, trans-septal, and palpebral lobe biopsy. Lateral orbitotomy was done in all excisional biopsy cases. We found no statistical difference in the histopathological outcome between the different surgical approaches used.

Conclusion

Nonspecific inflammation and lymphoproliferative disorders are the most common causes of lacrimal gland lesions. Blood work-up should not be used to waive off the need for lacrimal gland biopsy, and the diagnosis should preferably be based on histopathology results. The MRI is a useful tool to diagnose lacrimal gland lesions; however, histopathology remains the gold standard method.

Magnetic resonance imaging of the orbit, Part 2: Characterization of orbital pathologies

In this article we focus on a systematic approach to assess common orbital lesions on magnetic resonance imaging (MRI). The identification of the probable compartment or structure of origin helps narrow the differential diagnosis of a lesion. Analyzing the morphology, appearance, and signal intensity on various sequences, the pattern, and degree of contrast enhancement are key to characterize lesions on MRI. Imaging features suggesting cellularity and vascularity can also be determined to help plan for biopsy or surgery of these lesions. MRI can also distinguish active from chronic disease in certain pathologies and aids in selecting appropriate medical management. MRI may thus serve as a diagnostic tool and help in guiding therapeutic strategies and posttreatment follow-up.

Value of MRI-based radiomics analysis for differentiation of benign and malignant epithelial neoplasms in the lacrimal gland: a retrospective study

BACKGROUND

It is essential to distinguish malignant from benign epithelial neoplasms in the lacrimal gland for different treatment options and prognosis.

PURPOSE

To retrospectively assess the performance of magnetic resonance imaging (MRI)-based radiomics features in the differentiation of benign and malignant epithelial neoplasms in the lacrimal gland.

MATERIAL AND METHODS

Seventy-six consecutive patients with histopathology-proven epithelial neoplasms of the lacrimal gland were enrolled in the study, including 41 benign and 35 malignant neoplasms. Radiomics features were extracted from T2-weighted and post-contrast T1-weighted imaging. The least absolute shrinkage and selection operator method was used to select imaging features and reduce data dimension to discriminate malignant from benign neoplasms in the lacrimal gland. Diagnostic performance of the radiomics model was assessed by receive operation characteristic (ROC) curve and compared with that of radiologists.

RESULTS

Four quantitative image features including inverse difference moment normalized (IDMN), mean deviation (MD), standard deviation (SD), and long-run emphasis (LRE) were selected to distinguish malignant from benign epithelial neoplasms in the lacrimal gland. Area under the curve (AUC) of these four features were 0.88, 086, 0.88, and 0.86, respectively, with 0.93 for the combination model. The model identified malignant epithelial neoplasms from benign group with 89% sensitivity, 93% specificity, and 89% accuracy. There was a significant difference in the diagnostic performance of radiomics model and the radiologists, with AUC of 0.70 for radiologists. The diagnostic performance of radiomics is superior to that of radiologists.

CONCLUSION

MRI-based radiomics analysis has potential for differentiation of benign and malignant epithelial neoplasms in the lacrimal gland.

Value of quantitative multiparametric MRI in differentiating pleomorphic adenomas from malignant epithelial tumors in lacrimal gland

PURPOSE

To evaluate the diagnostic performance of the quantitative parameters derived from diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI in differentiating lacrimal gland pleomorphic adenomas (LGPAs) from lacrimal gland malignant epithelial tumors (LGMETs).

METHODS

Seventy-seven cases with LG epithelial tumors confirmed by histopathology (47 LGPAs and 30 LGMETs) underwent DWI and DCE-MRI. The quantitative parameters including the apparent diffusion coefficient (ADC), the volume transfer constant (K^trans), the efflux rate constant from the extravascular extracellular space (EES) to blood plasma (K_ep), and the extravascular extracellular volume fraction (V_e) were used to differentiate LGPAs from LGMETs. Independent-samples t test was conducted to compare these parameters. The diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Compared with LGPAs, LGMETs had significantly lower ADC value (1.090 ± 0.169mm²/s) (P < 0.001), higher K^trans value (0.892 ± 0.517/min) (P = 0.001), and K_ep value (1.300 ± 1.131/min) (P = 0.002). ADC as a diagnostic index showed a better diagnostic efficacy in predicting malignant tumors (AUC 0.914, sensitivity 90.0%, specificity 85.1%, and accuracy 87.0%) than K^trans and K_ep alone. The combination of ADC and K^trans presented the optimal diagnostic performance for the differentiation (AUC 0.938, sensitivity 93.3%, specificity 87.2%, accuracy 89.6%).

CONCLUSION

The quantitative parameters including ADC, K^trans, and K_ep derived from DWI and DCE-MRI might be potential imaging biomarkers in differentiating LGPAs from LGMETs. The combination of ADC and K^trans is superior to other quantitative parameters in distinguishing LGPAs from LGMETs.

Characterization of diffuse orbital mass using Apparent diffusion coefficient in 3-tesla MRI

Purpose

To evaluate if the apparent diffusion coefficient (ADC) value in diffusion-weighted magnetic resonance imaging (DW-MRI) improves the diagnostic accuracy of diffuse orbital masses.

Materials and methods

ADC DW-MRI was used to evaluate cases of diffuse orbital masses at our institution from 2000 to 2015. Lesions were grouped according to histopathologic diagnosis as, benign, pre-malignant and malignant. Lymphoproliferative lesions were further subgrouped as lymphoma or other lymphoproliferative lesions. The validity of the ADC value for the diffuse orbital mass was compared between groups. The area under curve (AUC) was also calculated.

Results

Thirty-nine cases of diffuse orbital masses were evaluated. The median ADC was 0.58 (25% quartile 0.48; minimum: 0.45; maximum: 1.72 × 10⁽⁻³⁾) for the malignant tumors and 1.19 (25% quartile 0.7; minimum: 0.5; maximum: 1.95 × 10⁽⁻³⁾ mm⁽²⁾ s⁽⁻¹⁾) for benign lesions. This difference in ADC between lesions was statistically significant (Mann Whitney U test P < 0.001). The median ADC was 0.51 (25% quartile 0.48) for lymphomas and 0.9 (25% quartile 0.7) for other lymphoproliferative lesions. This difference in ADC was statistically significant (Mann Whitney U test P = 0.02). An ADC value of 0.8 × 10⁽⁻³⁾ mm⁽²⁾ s⁽⁻¹⁾ was noted as the ideal threshold value for differentiating malignant from benign diffuse orbital masses. The validity of ADC in predicting a malignant or benign diffuse orbital mass had a sensitivity of 87%, specificity of 67% and accuracy of 88%.

Conclusion

ADC is a promising imaging metric to characterize malignant and benign diffuse orbital masses and to distinguish lymphomas from other non−lymphoproliferative lesions.

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.

Epithelial lacrimal gland tumors: A comprehensive clinicopathologic review of 26 lesions with radiologic correlation

AIM

To study the prevalence, clinicopathological and radiological correlations of epithelial lacrimal gland tumors and compare these with similar published literature. The study was also designed to look at the natural history of benign mixed tumors (BMT) in regard to recurrence and malignant degeneration.

METHODS

THIS WAS A RETROSPECTIVE STUDY OF ALL SUSPECTED EPITHELIAL TUMORS OF THE LACRIMAL GLAND SURGICALLY EXCISED AT KING KHALED EYE SPECIALIST HOSPITAL (KKESH) FOR THE PERIOD: 1983-2008. Exclusion criteria included structural lesions (dacryops) and inflammatory lesions. We included 26 cases of epithelial lacrimal gland tumors (from 24 patients). The histopathologic slides and the radiologic findings were reviewed. The corresponding demographic and clinical data were obtained by chart review using a data sheet.

RESULTS

BMT accounted for 12/26 of the lesions while malignant lesions including adenoid cystic carcinoma (ACC) were more common (14/26). The mean age was 44.27 years (range 12-75). Commonest clinical presentation was proptosis. Median duration of symptoms in the BMT cases was 30 months and 7 months in the ACC group. The 12 BMT cases were primary in 9 and recurrent in 3 patients. The 11 ACC cases showed mostly cribriform pattern and low histopathologic grade. We had 2 cases of malignant mixed tumor (MMT) one of which arising in a recurrent tumor. One case of primary mucoepidermoid carcinoma with histopathologic grade 2 was noted. Radiologically, a well-defined appearance with bone remodeling was observed in BMT in contrast to invasive appearance with destruction in malignant lesions.

CONCLUSION

Our series information indicated a different distribution of benign and malignant epithelial lesions with a slightly higher rate of malignancy. BMT was the commonest benign tumor where recurrence was a squeal of incomplete surgical excision. ACC was the commonest malignant tumor with shorter duration of symptoms and radiologic evidence of invasiveness that correlated with the histopathologic features.