Skeletal muscle and solitary bone metastases from malignant melanoma: multimodality imaging and oncological outcome

Abstract

Malignant melanoma solitary metastases to bone or skeletal muscle occur in 0.8% of patients. The aim of this study was to evaluate features of skeleton and muscle metastases with multimodality imaging and review the oncological outcome. Thirteen patients with melanoma metastases from January 2006 to February 2016 were included. Histologic confirmation was obtained. Imaging studies included computed tomography (CT), MRI, and/or positron emission tomography/CT. Treatment received and BRAF status were recorded. Differences in BRAF status and overall survival (OS) were analyzed using the χ2-test. Associations between OS and metastases were analyzed using Cox proportional models. Nine (69%) patients showed osseous involvement. Lower extremity bones were affected in three (23%) patients: first toe, right calcaneal spurs, and knee. The spine was involved in three (23%) patients. In two (15%) patients, the pelvic bones were involved. In one (8%) patient, the temporal bone was affected. Nine (70%) patients had a history of malignant melanoma, with a median time to progression of 28 months. The median OS was 18 months: 24 months in patients with a history of melanoma and 3 months in patients with metastases at first diagnosis. The median follow-up duration was 28 months. BRAF mutant versus wild-type tumors showed significant differences in OS (P=0.03). The hazard ratio for death in the metastatic group at diagnosis was 6.83, 95% confidence interval: 1.060–144.072 (P=0.04). Solitary metastases from melanoma to the skeleton and muscle are rare. CT, MRI, and positron emission tomography/CT are useful for the evaluation of musculoskeletal findings. Image findings are not definitive for diagnosing a malignant solitary lesion; thus, a pathologic confirmation with a biopsy is recommended.

Ablation of soft tissue tumours by long needle variable electrode-geometry electrochemotherapy: final report from a single-arm, single-centre phase-2 study

“…Nowadays, thanks to the continuous improvement of patient survival produced by systemic therapies, soft-tissue metastases are being encountered more frequently. They occur in 1.2-6.6% of STS patients 1,19 and, together with skin and lymph nodes, represent a primary site of diffusion of cutaneous melanoma [20][21][22][23] , and a possible modality of spread for carcinomas (e.g. lung, breast, kidney, and colon) and lymphoproliferative disorders 1,2,19,24 .…”

“…Seventeen patients (57%) developed new metastases in the skin/soft-tissue, after a median interval of 6 months (IQR 5-9). Twenty-six (87%) patients experienced systemic progression after a median of 8 months (IQR 5-11) and died after 15 months (IQR[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]…”

Diagnosis and treatment of melanoma bone metastasis: A multidisciplinary approach

“…In fact, both techniques go along with a substantial rate of false negative findings. 2,18,19 The diagnosis may be confirmed with a biopsy and pathological…”

“…Some studies showed that PET/CT technique is the gold standard to diagnose single bone involvement while MRI should be used to detect muscle involvement. 2 Other authors showed that PET/CT and MRI appear to be similarly appropriate for the identification of skeletal metastases in patients with malignant melanoma. In fact, both techniques go along with a substantial rate of false negative findings.…”

“…In fact, some authors reported that in only 3.7% of patients bone was found to be the first and only site of disease. 2 Melanoma metastases to skeleton and muscle occur in 11% to 17% of patients. 3 Nevertheless, autopsy series have shown that skeletal involvement is more common than it has been published in most clinical series.…”