Bellini duct carcinoma revealed by cutaneous metastasis: A case report

Cutaneous metastasis of renal cell carcinoma is rare and the majority of these metastases are asynchronous. The scalp and face are the major sites of metastases, followed by the chest and abdomen. However, the entire body surface can be affected. When diagnosed, patients are multi-metastatic in 50-80% of cases during follow-up post nephrectomy.

We report here a patient who consulted a dermatologist for multiple skin nodules that appeared 3 months prior. A skin biopsy of a nodule was performed and the pathological examination and immunohistochemistry profile confirmed a metastasis of Bellini Carcinoma, which is a renal cell carcinoma of the collecting duct. A thoraco-abdomino-pelvic scan showed a left renal tumor locally advanced with lung and liver metastases. Chemotherapy was indicated and the patient died four months after diagnosis.

Bellini carcinoma is a very rare type of carcinoma of renal cell origin with a very poor prognosis as it is diagnosed already at a metastatic state in the vast majority of cases. After analysis of the data from the literature, our case is the second reported case of a Bellini carcinoma revealed by cutaneous metastases. The peculiarity of our observation is metastases occurred on all four limbs and at the trunk level, and the asymptomatic characteristic of Bellini's carcinoma, which is a rare situation.

The originality of this observation is based on the mode of presentation of a rare renal tumor by an even rarer metastasis of the skin.