Lacrimal gland pleomorphic adenoma and malignant epithelial tumours: clinical and imaging differences

Evaluation of orbital lesions with DCE-MRI: a literature review

PURPOSE

To provide a major review on the applications of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in evaluating orbital lesions. This review also outlines selected scenarios where DCE-MRI may be helpful.

METHODS

A comprehensive retrospective literature review of all English language publications on PubMed, EMBASE, and Google Scholar between 1994 and 2022. This literature review examined the specific applications and clinical scenarios surrounding the utility of DCE-MRI in orbital lesions and various findings that have been presented in the current literature.

RESULTS

DCE-MRI provides information on tissue physiology and permeability, beyond the anatomical features displayed on static imaging. Various measured parameters (qualitative, semi-quantitative, and quantitative) obtained by DCE-MRI have been used to differentiate between benign and malignant lesions, specific orbital lymphoproliferative diseases (OLPD), lacrimal gland lesions, and various rare orbital tumours. DCE-MRI has a limited role as an initial diagnostic imaging modality. However, DCE-MRI may prove to have benefit in predicting and monitoring treatment response in orbital lymphoma as a critical imaging study, but literature specific to orbital malignancies remains limited.

CONCLUSION

The value of DCE-MRI may be in situations of diagnostic uncertainty, where it may be an additional imaging aid following conventional imaging techniques. It may also act as a critical imaging modality for monitoring of orbital tumour treatment response, but the literature remains limited. Standardisation of imaging protocol, measured parameters, and statistical analysis remain limitations of this imaging technique.

Presumed Lacrimal Gland Pleomorphic Adenoma With Extensive Ossification and Necrosis

Calcification within pleomorphic adenomas of the lacrimal gland is well recognized but uncommon, being seen more readily in lacrimal gland carcinomas. Bony formation, ossification, in pleomorphic adenomas of the lacrimal glands is even rarer. Together with extensive sclerosis, or "coagulative necrosis," ossification and necrosis should alert the clinician to the risk of malignant transformation. However, both can mimic carcinomatous change, leading to misinterpretation of malignancy in an otherwise benign lacrimal gland neoplasm. We present 2 case reports of patients with clinically presumed pleomorphic adenomas of the lacrimal gland whose histopathology demonstrated lacrimal gland ossification and necrosis without features of malignancy or invasive disease.

Diagnostic value of dynamic contrast enhancement combined with conventional MRI in differentiating benign and malignant lacrimal gland epithelial tumours

AIM

To establish the diagnostic value of the quantitative parameters of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) combined with conventional MRI in differentiating of benign and malignant lacrimal gland epithelial tumours.

MATERIALS AND METHODS

A retrospective analysis of primary lacrimal gland epithelial tumours confirmed by histopathology was conducted. Conventional MRI features and DCE-MRI quantitative parameters were collected and subjected to analysis. The diagnostic value was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 53 patients were enrolled of which 29 had malignant, whereas 24 had benign tumours. Conventional MRI revealed statistically significant differences between benign and malignant tumours regarding maximum tumour diameter, posterior margin characteristic, bone destruction, and erosion. The Ktrans and Kep values obtained by DCE-MRI were higher in malignant than in benign tumours, with a statistically significant (p<0.001 and p=0.022). A type I time-signal intensity (TIC) curve was more frequent in benign tumours, whereas a type II TIC curve was prevalent in malignant tumours (p=0.001). ROC analysis showed that Ktrans had the best diagnostic value of the DCE-MRI parameters (area under the ROC curve [AUC] of 0.822, 75.9% sensitivity, and 83.3% specificity, p<0.001). The combination of conventional MRI and DCE-MRI factors had the best diagnostic value and balanced sensitivity and specificity (AUC of 0.948, 93.1% sensitivity, and 91.7% specificity, p<0.001).

CONCLUSIONS

The present findings indicate that the combination of quantitative parameters of DCE-MRI and image characteristics of conventional MRI have a high diagnostic value for the diagnosis of benign and malignant lacrimal gland epithelial tumours.

Incidence, clinical features, and survival outcomes of primary malignant lacrimal gland tumors: A population-based analysis

BACKGROUND

Studies on the epidemiological information and prognosis of primary malignant lacrimal gland tumors (MLGTs) are rare for its low occurrence. The goal of our research was to investigate the epidemiological characteristics and survival outcomes of patients with MLGTs.

METHODS

Incidence and demographic information of patients with MLGTs were collected from the Surveillance, Epidemiology, and End Results (SEER) database. To identify independent prognostic factors for disease-specific survival (DSS) and overall survival (OS), univariate and multivariate Cox regression analysis were performed.

RESULTS

The overall incidence of primary MLGTs from 1975 to 2020 was 0.413/1,000,000 (according to the 2000 American standard population), with a steadily increasing incidence over years. A total of 964 patients with primary MLGTs were diagnosed, with an average age of 59.3 years. Of these, 53.2% were aged ≥60 years, 57.4% were female, and 77.1% were whites. Multivariate Cox regression analysis demonstrated that year of diagnosis, age, sex, histological type, SEER stage, surgery, and chemotherapy were independent prognostic factors of DSS or OS.

CONCLUSIONS

Although primary MLGT is rare, its incidence has steadily increased in the past 46 years, and surgery was related to a better prognosis.

Recurrent lacrimal gland pleomorphic adenoma

Pleomorphic adenoma is the most common tumour of the lacrimal gland. Correct preoperative diagnosis is essential as the tumour should be removed en bloc. Incisional biopsy is contraindicated due to risk of recurrence and subsequent risk of malignancy. We identified 13 patients who were diagnosed with lacrimal gland pleomorphic adenoma in our institution over a 31-year period from 1990 to 2021. Of these, we describe four patients, three males and one female, who underwent incisional biopsy. One of these patients had a number of recurrences and required an orbital exenteration. The other two were treated with radiation to the orbit and experienced severe dry eye post-radiotherapy. All three patients are currently disease-free. The fourth patient underwent an incisional biopsy of his lacrimal gland pleomorphic adenoma (LGPA) within the last 6 months and has been referred for radiotherapy. The reasons for a lack of preoperative diagnosis of LGPA included clinical uncertainty and broad radiologic differential. None of the patients who had an en bloc resection experienced recurrence. We recommend that a fine needle aspirate (FNA) biopsy in lieu of a tissue biopsy should be performed where LGPA is included in the clinical and radiological differential diagnosis. If incisional biopsy is required, the suture track should be marked so that the entire biopsy track is removed with the specimen.

Advances in clinical examination of lacrimal gland

In humans, the lacrimal gland is located in the socket of the frontal bone above the outer orbital area. As an essential part of the eye surface, the gland is fixed to the orbital periosteum by connective tissue. The lacrimal gland passes through the outer tendon membrane, which divides the gland into larger orbital and minor eyelid glands. The lacrimal glands are the main contributors to tear film. They secrete electrolytes, proteins, and water to help nourish and protect the eye's surface. Furthermore, clinically, lacrimal glands are associated with a variety of inflammatory reactions and immune factors and are also vulnerable sites for tumors. Changes in tear gland morphology or secretory function affect tear film stability and tear secretion quality. Various technological devices have been developed and applied to lacrimal glands. This article systematically reviewed the clinical examination of the lacrimal gland to help inform personalized strategies for the diagnosis of lacrimal gland-related diseases.

Orbital Tumors-Clinical, Radiologic and Histopathologic Correlation

Orbital masses include a broad spectrum of benign and malignant entities. Often these masses are asymptomatic or show a slow growth rate, so that emergence of clinical symptoms is prolonged. In this context, cross-sectional imaging plays an elementary role in the characterization of these lesions. Aside from the characterization of the underlying entity, an evaluation of the involved compartments is possible by sufficient imaging, which also facilitates optimal treatment and surgery planning. The purpose of this review is to explore different benign and malignant orbital tumors and their typical appearance in imaging together with histopathologic findings.

Masses of the Lacrimal Gland: Evaluation and Treatment

Lacrimal gland lesions account for approximately 9 to 10% of all biopsied orbital masses. Potential causes include nongranulomatous and granulomatous inflammation, autoimmune disease, lymphoproliferative disorders, benign epithelial proliferation, malignant neoplasia, and metastatic disease. Inflammatory lesions and lymphoproliferative disorders are the most common and may be unilateral or bilateral; they may also be localized to the orbit or associated with systemic disease. Both benign and malignant epithelial lacrimal gland masses tend to be unilateral and involve the orbital lobe, but a more rapid onset of symptoms and periorbital pain strongly suggest malignant disease. On orbital imaging, both inflammatory and lymphoproliferative lesions conform to the globe and surrounding structures, without changes in adjacent bone, whereas epithelial lacrimal gland masses often show scalloping of the lacrimal gland fossa. Malignant epithelial lacrimal gland tumors can also have radiographic evidence of bony invasion and destruction. Masses of the lacrimal gland may be due to a broad range of pathologies, and a good working knowledge of common clinical characteristics and radiographic imaging findings is essential for diagnosis and treatment. All patients with inflammatory, lymphoproliferative, and epithelial neoplastic lesions involving the lacrimal gland require long-term surveillance for disease recurrence and progression.

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.

Lacrimal gland pleomorphic adenoma: a review of 52 cases, 15-year experience

BACKGROUND

Lacrimal gland (LG) tumours are rare neoplasms. Pleomorphic adenoma (PA) is the most common histologic variant, representing ∼20% of all LG tumours. PA tends to recur leading to great morbidity.

AIMS

We carried out this study to share our experience and provide recent data on the clinical aspects, radiologic findings, management and outcome after treatment.

METHODS

We realised a hospital-based retrospective case review including data collected from 52 patients, managed over 15 years.

RESULTS

The mean age was 39.8 ± 2 years. Unilateral painless proptosis was the most constant sign (51.9%). CT-scan showed predominantly isodense lesions (96.2%), with regular borders (94.2%), measuring on average 2 cm. MRI showed isointense lesions on T1-weighted images in 96.2% of cases. No pre-operative biopsy was done. Surgical management was mainly external lateral orbitotomy (94.2%). There was no recurrence, considering a mean follow-up period of 12.6 years. Size of tumour at the time of diagnosis increased with age (r = +0.36, p = .01).

CONCLUSIONS

Clinical and radiologic characteristics are consistent with literature. Older patients seem to present larger tumours. We believe that biopsy is not necessary if appropriate imaging is done. Complete, intact resection is generally sufficient to minimise the risk of recurrence.