Liver Imaging Techniques: Recognition of Uveal Melanoma Metastases

Abstract

Background: The liver is the most common site for metastases of several primary malignancies including uveal melanoma. Methods: Review of imaging characteristics of incidental common benign liver lesions including hepatic cyst, hemangioma, focal nodular hyperplasia, and hepatic adenoma and contrasting them with uveal melanoma metastases. Results: Benign hepatic lesions may be cystic or, if solid, relatively stable in size over time. For hepatic lesions larger than 10 mm in size, characteristic imaging features typically allow for confident diagnosis. When lesions are small (less than 10 mm), definitive characterization can be difficult. Moreover, lesions smaller than 10 mm can be difficult to biopsy under ultrasound or computed tomography (CT) guidance, and short-term follow-up will often be useful to assess for stability or progression. Overall, magnetic resonance imaging is more specific than CT scan and at least as sensitive as CT for detecting uveal melanoma liver metastases. Conclusions: New multiple enhancing solid liver lesions should raise suspicion of uveal melanoma liver metastases. Discussion of challenging cases with the radiologist may be beneficial, as pertinent information such as size, location, and molecular prognostication status of the primary tumor can guide radiological interpretation of hepatic lesions.

Prospective Evaluation of Risk-Appropriate Management of Uveal Melanoma Patients Informed by Gene Expression Profiling

“…It is important to note that systemic surveillance for UM patients, while recommended in NCCN guidelines, remains controversial as there is currently no curative therapy for metastatic UM. Consequently, there is no consensus regarding which imaging modality/modalities and what frequency is best for surveillance of presumed subclinical micrometastasis in UM patients [18]. In the current study, fewer than 30% of all patients were recommended liver function testing, the utility of which has not been demonstrated to aid in early detection of hepatic metastasis [19].…”

“…In the current study, fewer than 30% of all patients were recommended liver function testing, the utility of which has not been demonstrated to aid in early detection of hepatic metastasis [19]. On the other hand, surveillance via a form of systemic imaging (x-ray, hepatic ultrasound, CT or MRI) was recommended for a majority of both class 1 and class 2 patients, and has been shown to aid in the detection of subclinical metastases in primary UM patients [18,20]. Together, these data indicate that physicians are using an evidence-based approach to guide decision making regarding metastatic surveillance of UM patients, and that distinguishing class 1 from class 2 tumors impacts patient care.…”

Intra-operative ocular ultrasonography of iodine-125 brachytherapy plaques in patients with uveal melanoma

“…Regardless of the local response in each case, high-risk cases (class 2 findings) were followed up by abdominal nuclear magnetic resonance imaging, every four months for the first three years after brachytherapy. For cases with moderate-risk (class 1 biopsy findings of cases without any result of prognostic biopsy), abdominal ultrasound was performed every six months, for up to five years follow-up[ 32 , 33 ].…”

Application of Multimodal and Molecular Imaging Techniques in the Detection of Choroidal Melanomas

“…Mariani et al believe that the number and maximum surface area (>800mm 2 ) of metastasis under MRI can be used as important indicators to predict the survival rate of patients (65). Because of the vascular richness in uveal melanoma, a metastasis on MRI appears as multiple enhanced solid liver lesions with the high T1 signal characteristic of melanomas (68). Diffuse-weighted images (DWI) can be used to detect more metastasis, which appearances as the high signal, and the lesion can still exist when the dispersion sensitivity coefficient is adjusted to the highest, thus more metastasis < 5mm can be detected, regardless of the location of the metastasis in the liver (65).…”