腎盂泌尿上皮細胞癌之皮膚轉移：罕見病例報告

蕭伯任^{1, 2}、王紹全^{1, 2}

¹中山醫學大學附設醫學泌尿科；²中山醫學大學醫學研究所

Cutaneous Metastasis of Renal Pelvis Urothelial Carcinoma: A Rare Case Report

Po-Ren Hsiao^{1, 2}、Shao-Chuan Wang ^{1, 2}

¹Department of Urology, Chung Shan Medical University Hospital, Taichung, Taiwan;² Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan

Introduction

Cutaneous metastasis from urothelial carcinoma is an exceedingly rare clinical manifestation. Urothelial carcinoma most commonly metastasizes to lymph nodes, lungs, liver, and bone, whereas skin involvement is uncommon and may be underrecognized due to its variable clinical presentation. The presence of cutaneous metastasis typically indicates advanced systemic disease and is associated with a poor prognosis.

Case Presentation

We report a 91-year-old woman with a history of high-grade urothelial carcinoma of the right renal pelvis who underwent robot-assisted radical nephroureterectomy with bladder cuff excision approximately six years prior. The initial tumor stage was pT3N0M0. However, the patient declined further systemic treatment due to impaired renal function and was subsequently lost to follow-up.

She later presented with multiple skin lesions over the left flank and inguinal region. On physical examination, the lesions appeared as erythematous to violaceous nodules measuring approximately 1–3 cm in diameter. They were firm, dome-shaped, and partially coalescent, with overlying focal ulceration, crusting, and surrounding erythema. Some nodules demonstrated dusky to purplish discoloration and were fixed to the underlying tissue with ill-defined margins.

Abdominal computed tomography revealed progression of metastatic lymphadenopathy involving the aortocaval, paraaortic, bilateral iliac, and inguinal regions, with focal necrosis and vascular encasement. Excisional biopsy of the skin lesions demonstrated immunohistochemical positivity for GATA3, p63, CK20, and cytokeratin, consistent with metastatic urothelial carcinoma. Given the advanced disease status, treatment was palliative in nature. The patient’s condition deteriorated rapidly, and she expired within three months of diagnosis.

Discussion and Review

The occurrence of cutaneous or subcutaneous metastasis reflects aggressive tumor biology and is associated with a poor prognosis. The clinical appearance of cutaneous lesions is variable and often nonspecific, which may delay diagnosis. Definitive diagnosis relies on histopathological examination with immunohistochemical confirmation. Management is primarily palliative and depends on the extent of systemic disease, including chemotherapy, immunotherapy, or local interventions for symptomatic relief.  Clinicians should maintain a high index of suspicion when evaluating new skin or soft tissue lesions in patients with a history of urothelial carcinoma. Early recognition may facilitate timely diagnosis and appropriate multidisciplinary management, although the overall prognosis remains guarded.