Diagnostic methods and therapeutic options of uveal melanoma with emphasis on MR imaging—Part I: MR imaging with pathologic correlation and technical considerations

Abstract

Uveal melanoma is a malignant neoplasm that derives from pigmented melanocytes of the uvea and involves, in order of decreasing prevalence, the choroid, ciliary body and iris. Its prognosis is related to histopathologic and genetic features, tumor size and location, extraocular extension. The diagnosis is fundamentally based on clinical evaluation (ophthalmoscopy, biomicroscopy) and ultrasonography. MRI is useful in case of untransparent lens or subretinal effusion. Moreover, MRI has a significant role to confirm the diagnosis, in the evaluation of the local extent of the disease with implications for treatment planning, and in the follow-up after radiotherapy treatment. Uveal melanoma can show different morphologic features (lentiform, dome or mushroom shape) and often determines retinal detachment. MR appearance of uveal melanoma mainly depends on the melanin content. Uveal melanoma typically displays high signal intensity on T1-weighted images and low signal intensity on T2-weighted images. Nevertheless, imaging appearance may be variable based on the degree of pigmentation and the presence of areas of necrosis or cavitation. Differential diagnosis includes other uveal lesions. The radiologists and in particular MRI play a significant role in the clinical management of uveal melanoma. The purpose of this pictorial review is to provide the radiologists with awareness about diagnostic methods and therapeutic options of uveal melanoma. In the present first section we summarize the MR anatomy of the eye and describe ophthalmological and radiological imaging techniques to diagnose uveal melanomas, with emphasis on the role of MR imaging. Additionally, we review MR imaging appearance of uveal melanomas.

MR imaging characteristics of uveal melanoma with histopathological validation

“…Imaging UM with MR requires a dedicated eye protocol consisting of 2D MS TSE sequences, which are indispensable for delineating tumor boundaries; 3D TSE sequences, which allow retrospective reformatting in all directions and 3D reconstructions, and are essential to assess tumor geometry and accurate measurements; and DWI and PWI sequences, which aid in the differential diagnosis, and potentially, provide prognostic information, predict treatment response, and permit earlier assessment of tumor response to radiotherapy than US [3,8,11,[14][15][16][17][18].…”

“…Moreover, the radiotherapy planning of UM with complex tumor shapes, such as some tumors with a mushroom configuration, is more difficult and deserves special attention [20]. The mushroom configuration is associated with breaks in Bruch's membrane [11,21]. Our study was consistent; we showed the importance of The amount of pigmentation in UM is variable, and although pronounced pigmentation has been associated with a less favorable prognosis [19], the accurate prognostic significance of pigmentation warrants further analysis [22].…”

“…However, recent developments on MRI allow good quality images [8]. Moreover, with a high soft tissue contrast and spatial resolution, the possibility of generating 3D volumetric and functional images, and the possibility of evaluating UM in eyes of vitrectomized patients with a SiOil tamponade, MRI seems to be of added value in comparison with US [8,[11][12][13].…”

Prognostic Value of the Immunohistochemical Expression of Serine and Arginine-Rich Splicing Factor 1 (SRSF1) in Uveal Melanoma: A Clinico-Pathological and Immunohistochemical Study on a Series of 85 Cases

“…Melanoma of the uveal tract is an uncommon malignancy, mainly affecting middleaged adult patients, primarily arising from the choroid and less frequently from the ciliary bodies and iris [1][2][3][4]. Uveal melanoma (UM), despite representing the most common primary intraocular malignant tumor of the adult age, is exceptionally unusual in the pediatric population in which it usually has congenital origin with poorer outcome and more frequent extraocular extension at the diagnosis [5].…”

“…Risk factors that have historically been reported to be involved in the development of this neoplasm include: Fitzpatrick phototypes I-II, type 1 neurofibromatosis (NF-1), oculo-dermal melanocytosis (Ota nevus), dysplastic nevus syndrome, and choroidal nevi [5][6][7]. Although UM typically tends to remain asymptomatic for years before the diagnosis, a sudden retinal detachment often represents the presenting symptom of the tumor [1][2][3][4][5]. UM is a slow-growing tumor with indolent biological behavior but consistently poor prognosis, characterized by the development of liver metastases within 10-15 years after the diagnosis in about 50% of cases [6][7][8][9].…”