Metastatic melanoma of the spine usually occurs as vertebral metastatic melanoma or intramedullary spinal cord metastatic melanoma.

Spine metastasis of melanoma carries the potential for difficult problems, such as pain, weakness and sensory deficit.

MRI reveals an increased signal intensity in the vertebral body, with soft-tissue extension into the extradural space.

MRI scans of intraspinal melanomas show hypointense signals on T2-weighted images and hyperintense signals on T1-weighted images.

T1 hyperintense signal intensity on MR imaging in melanoma has been attributed to hemorrhage or melanin ¹⁾.

Usually, the confirmatory diagnosis of spinal melanoma is only made on the basis of post-surgical pathological studies or autopsies.

Immunohistochemical studies are also important in a diagnosis. Anti-melanoma antibody (HMB-45) and S-100 protein staining may aid in the diagnosis of malignant melanoma. Furthermore, immunohistochemistry may be used to distinguish spinal melanoma from other types of tumors.

Surgical resection of spinal melanomas is extremely important as it leads to the regression of neurological symptoms.

Although the efficacies of radiotherapy and chemotherapy remain controversial in melanoma, radical removal of the tumor should be followed by radiotherapy due to the malignant nature of this tumor ²⁾.

The management of metastatic spinal melanoma involves maximizing local control, preventing recurrence, and minimizing treatment-associated toxicity and spinal cord damage. Additionally, therapeutic measures should promote mechanical stability, facilitate rehabilitation, and promote quality of life. These objectives prove difficult to achieve given melanoma's elusive nature, radioresistant and chemoresistant histology, vascular character, and tendency for rapid and early metastasis. Different therapeutic modalities exist for metastatic spinal melanoma treatment, including resection (definitive, debulking, or stabilization procedures), stereotactic radiosurgery, and immunotherapeutic techniques, but no single treatment modality has proven fully effective.

Protocols that incorporate specific, goal-defined surgery, immunotherapy, and stereotactic radiosurgery would be beneficial in efforts to maximize local control and minimize toxicity ³⁾.

Sellin et al. retrospectively reviewed all patients (n = 64) who received surgical intervention for melanoma metastases to the spine at the University of Texas MD Anderson Cancer Center between July 1993 and March 2012.

No patients were excluded from the study, and vital status data were available for all patients. Median overall survival was 5.7 months (95% confidence interval, 2.7-28.7). On univariate survival analysis, diagnosis of spinal metastasis after prior diagnosis of systemic metastasis, higher total spinal disease burden (including but not exclusive to the operative site), presence of progressive systemic disease at the moment of spine surgery, and postoperative complications were associated with poorer overall survival, whereas the presence of only bone metastasis at the moment of surgery was associated with improved overall survival. On multivariate survival analysis, both progressive systemic disease at the moment of spine surgery and total spinal disease burden of ≥3 vertebral levels were significantly associated with worse overall survival (hazard ratio, 6.00; 95% confidence interval, 3.19-11.28; P < .001; and hazard ratio, 2.87; 95% confidence interval, 1.62-5.07; P < .001, respectively).

On multivariate analysis, involvement of ≥3 vertebral bodies and progressive systemic disease were associated with worse overall survival. Consideration of these factors should influence surgical decision making in this patient population ⁴⁾.

Ishii et al. reviewed reports of nine cases of intramedullary spinal cord metastatic melanoma ⁵⁾.

In 133 patients pain was the most common presenting symptom.

The radiographic diagnosis is generally made easily by plain radiographs, computed tomography or magnetic resonance imaging, with the most frequent finding being a destructive lesion. Bone scan gave false-negative results 15% of the time.

Although spine metastasis from melanoma is an uncommon event, it can pose a complex management problem.

Palliation should be the goal of treatment, but symptom management should be individualized, bearing in mind the short anticipated survival of these patients.

The median survival for the group was 4 months. It is concluded that melanoma metastatic to the spine represents a late event in the evolution of this illness. ⁶⁾.

From 7010 consecutive patients with melanoma, 114 were identified with clinically or radiographically evident spinal metastases. A comparison was made between these patients and the remainder of the population with melanoma seen at the institution using contingency table analysis with statistical significance determined by a chi-squared test. Survival data were represented by Kaplan-Meier curves, and log-rank testing was used for statistical comparisons.

Risk factors associated with the development of these metastases included primary lesions that were ulcerated, deeper than 0.76 mm, or of Clark level II, or located on the trunk or mucosal surfaces. The median survival time for all patients was 86 days, but this was reduced in patients with more than one metastatic site in addition to the spine ⁷⁾.

Electrochemotherapy allowed a successful treatment of metastatic spinal melanoma. There is a strong scientific rationale to support the potential utility of Electrochemotherapy as a novel treatment of spinal metastasis, regardless of the histological types ⁸⁾.