The importance of ultrasound-guided biopsy: lesson from a case of liver metastasis from uveal melanoma.

Melanoma is an extremely aggressive malignant neoplasm. Uveal melanoma is the most common primary intraocular malignancy in adults, representing 3-5% of all melanomas. Liver metastases can be clinically detected in 10-20% of patients with metastatic disease from cutaneous melanoma. However, while liver is typically not the first site of disease spread in cutaneous melanoma, ocular melanoma has been showed to primarily metastasize from the eye to the liver; indeed, liver metastases are detected in approximately 87% of patients with metastatic uveal melanoma. Therefore, liver metastasis can be challenging to identify in early stages, thus being essentially asymptomatic until the disease has advanced. Here we report the case of a patient who came to our ultrasound unit reporting a large liver mass. Both contrast-enhanced abdominal computed tomography and magnetic resonance imaging did not establish a definitive diagnosis. The final diagnosis was made only through an ultrasound-guided biopsy of the mass, thus revealing a uveal melanoma metastasis. This is followed by a review of the literature on imaging follow-up of patients with melanoma.