Endocrine Abstracts

Introduction: Clear cell renal carcinoma (ccRCC) is a subtype of renal cell carcinoma, the most frequent one (80%) and usually affecting only one kidney. It is twice as common in men than women between 50 to 70 years old. It can be associated with some genetic conditions that predispose patients to ccRCC, like Von Hipple-Lindau disease. Some clinical observations and molecular studies raised the hypothesis that RCC is a hormone−dependent tumor.

Case reports: We present three cases of ccRCC associated with various endocrine patterns.

Our first case is a 45-year-old man, with a family history of papillary thyroid carcinoma and ccRCC, left nephrectomy for ccRCC and nontoxic multinodular goiter. One year after nephrectomy, he underwent total thyroidectomy (confirmed histopathological to be a papillary thyroid carcinoma). The second case is a 46-year-old woman who underwent a partial right nephrectomy and right adrenalectomy. The histopathological exam revealed ccRCC and adrenal metastasis of ccRCC. MRI scan showed left longissimus thoracic muscle nodule and left adrenal nodule suggesting metastasis, while having a normal adrenal function. The patient was referred to initiate immunotherapy, therapy that can lead to thyroid disfunction. Our third case is a 52-year-old woman, known with lupus, without documented lupic nephritis, and left nephrectomy for ccRCC. One year after nephrectomy, the patient contracted left shoulder pain, which led to the diagnosis of left humeral osteolytic metastasis, so she started Sunitinib treatment (4 weeks on, 2 weeks off). Six months later, she developed sever hypothyroidism (TSH=320×μUI/ml) and began replacement therapy. All our cases are peculair.

Age at diagnosis was lower than the known mean age (64 years). Men are predisposed to develop first thyroid cancer (opposite to our case), then kidney cancer, with a distance between the two cancer diagnoses of 5.2 years. Bilateral adrenal metastases are rare (<0.5%), particularly in case of melanoma, thyroid, hepatocellular and bladder cancer, not in ccRCC. Hypothyroidism is a side effect of Sunitinib (TKI), in patient with underlying autoimune thyroid condition, or through the inhibition of VEGFR and/or PDGFR\. During the treatment with Sunitinib, the patient may need a higher dose of levothyroxine than during the treatment break.

Conclusion: The risk of developing another primary tumor is three times higher in patients with RCC versus other oncology patients. The gold standard in localized RCC is nephrectomy and local lymphadenectomy. In case of metastatic RCC, some of the treatment options are TKI (sunitinib e.g.) and immunotherapy.