Isolated metachronous cutaneous metastases from renal cell carcinoma

Abstract

Sir, Cutaneous metastases from renal cell carcinoma (RCC) are unusual and its incidence has been reported to be 1-3.3%.[12] There is need for a high index of suspicion in evaluating a patient presenting with a skin tumor, which can be synchronous or metachronous.[23] They typically indicate coexistent disseminated disease and a poor prognosis. The scalp and face are the commonest sites of cutaneous metastases in RCC.[12] The proposed mechanisms of cutaneous metastatic dissemination include direct invasion from underlying neoplasm, implantation in an operative scar, lymphatic permeation, and hematogenous spread.[45] The clinical appearance of skin metastases can be of 3 types: nodular (majority), inflammatory, and fibrotic.[25] Cutaneous lesions may be flesh colored, but often range from erythematous red to violaceous hues. They are often multiple but may also present as solitary metastasis. The average interval from the appearance of skin lesions to death is reportedly 12.7 months.[25] The treatment options for such lesions are generally limited and supportive. Whereas diffuse metastases should be treated with appropriate systemic therapy, focal cutaneous metastases may be surgically excised or treated with radiotherapy or a combination of the two.[25] We report an unusual case of isolated metachronous cutaneous metastases from a low-stage RCC. Very few such case reports have been described in world's literature on the subject. Interestingly, this is the first reported case from India in which isolated metachronous cutaneous metastases, albeit at 2 locations, have been noted. A 62-year-old male patient presented a year ago with recurrent episodes of gross hematuria and right flank pain of 6 months duration. Contrast-enhanced computed tomography (CECT) of the abdomen showed a heterogenous right renal mass (12 Χ 10 cm) abutting the ascending colon and hepatic flexure [Figure 1]. There was no evidence of any lymphadenopathy and distant metastases. The patient underwent a right open radical nephrectomy. Histopathology revealed a clear cell variant of RCC, confined to the renal capsule, with tumor-free surgical margins (pT2 N0 M0). Three months postoperative follow-up physical examination, chest radiograph, and abdominal sonogram were normal. At 11 months of follow-up, the patient noticed asymptomatic, rapidly enlarging nodules on the chin and scalp, appearing simultaneously around a month prior to reporting to the hospital. Examination revealed a purplish colored fleshy nodule (2 Χ 2 cm) arising on the right parietal region of the scalp. There were similar 2 nodules on the chin (1Χ2 cm), which had a subcutaneous component [Figures 2 and 3]. On palpation, they were nonpulsatile, freely movable over underlying bones. Serum biochemical parameters, including liver function tests were normal. CECT of the abdomen, chest radiograph, and bone scan were also normal. Excisional biopsies of the nodules were performed, which were consistent with the diagnosis of metastatic deposits from RCC [Figures 4 and 5]. The patient was subsequently treated with systemic immunotherapy. At 9 months of follow-up after metastatectomy, the RCC patient is well and has no evidence of other metastases.Figure 1: Contrast enhanced computed tomography (CECT) of the abdomen showing an enhancing heterogeneous mass replacing the inferior pole of the right kidneyFigure 2: Two fleshy, reddish purple nodular metastatic cutaneous deposits on the chin.Figure 3: Metastatic cutaneous deposit on the scalpFigure 4: Photomicrograph showing part of epidermis with metastatic renal cell carcinoma in dermis (H and E, ×40)Figure 5: Photomicrograph showing a sheet of clear cells of metastatic renal cell carcinoma with distinct cellular outlines and centrally placed nuclei in the skin H and E, ×200Thus, patients with low stage RCC at the time of nephrectomy may also develop cutaneous secondaries, sometimes after several months. In these patients the role of biological response modifiers needs to be evaluated.