Abstract
Cutaneous metastases represent only 2% of all skin tumors and are seen in 0.6%10.4% of patients with malignancies. Malignant urologic tumors generally metastasize to regional lymph nodes, liver, lungs, and bones. Cutaneous metastasis of urothelial carcinoma is uncommon with a reported incidence of 0.84%. We describe a case of a 73-year-old man who presented with progressively enlarging, indurated plaque with erythema and tender to palpation in the left flank extending anteriorly to the left groin. He had a history of left nephrectomy for renal cell carcinoma and cystoprostatectomy for T4b high-grade urothelial carcinoma 12 and 10 years prior respectively. He underwent a kidney transplantation for end-stage renal disease one year prior to this presentation. Tunnel punch biopsy of the left flank plaque showed panniculitis with scattered malignant cells. These cells expressed AE1/AE3, GATA3, p63, high molecular weight cytokeratin by immunohistochemistry and were negative for PAX8. This immunoprofile in the context of the known urothelial carcinoma, was consistent with metastasis. Fourteen months after this presentation, the imaging studies showed metastatic disease in the spine and the patient died of the disease three months later. This case demonstrates an unusual occurrence of isolated cutaneous metastatic urothelial carcinoma 10 years after initial diagnosis, notably few months following the initiation of immunosuppressive therapy after kidney transplantation. Immunohistochemistry and careful attention to a patients medical history helps to confirm the diagnosis. Metastatic carcinoma must be added to the differential diagnosis of panniculitis.
Financial Disclosure:
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