Malignant rhabdoid tumor beside benign skin mesenchymal neoplasm with myofibromatous features

Only a few reports of primary cutaneous rhabdoid tumors have been published. We describe the case of a 3-month-old female patient who developed a rhabdoid type cutaneous sarcomatoid neoplasm in her upper back, close to a benign myofibromatous proliferation of infancy. The lesion was studied both by light microscopy and immunohistochemically. Flow cytometry was performed showing a DNA diploid profile of the malignant tumor. The pathological findings suggest a mesenchymal origin (hemangiopericytic or myofibroblastic type) for both tumors. The patient was surgically treated, but she died nine months later.