Isolated rectus abdominis metastasis from melanoma—An extremely rare case

INTRODUCTION: Melanoma is a health problem world-wide. Its incidence has tripled in the last decade. The main cause of death in melanoma patients is widespread metastases. It can metastasize to almost every organ. However, melanoma skeletal muscle metastases (MSMM) are exceptional, and only two cases of MSMM to rectus abdominis muscles have been previously published. Regardless of all new advances seen in melanoma therapy, cure for most MSMM is still elusive. Surgical approaches are still not well defined. PRESENTATION OF CASE: A 35-year-old woman had been previously operated of an ulcerated scapular melanoma (Clark level III, Breslow 2.3 mm) in January 2014. Subsequently she underwent a sentinel lymph node which resulted negative. Twenty months later, a CT scan revealed a well-enhanced nodule of 25 mm in the right rectus abdominis, without any other metastases. The PET-CT uptake was pathologic (SUV maximum of 13.16). An ultrasound-guided biopsy confirmed it was a metastatic melanoma. A radical compartmental resection of the right rectus abdominis muscle was performed. The abdominal wall was reconstructed with two polypropylene meshes buried preperitoneally. The final histologic diagnosis of the specimen proved to be a metastasis of melanoma. DISCUSSION: Surgery is the only potentially curative therapy for patients with isolated MSMM. The ultimate goal of negative resection margins, in order to avoid local recurrences, is paramount in those difficult cases. CONCLUSION: Radical compartmental surgery should be considered for selected stage IV melanoma patients whose disease could be amenable to complete resection, in order to extend median survival.