Primary extra-renal clear cell renal cell carcinoma masquerading as an adrenal mass: A diagnostic challenge

A Rare Case of Extra-renal Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the predominant solid lesion found in the kidney. Extra-renal RCC is a rare entity. We present the case of a 75-year-old male with an incidentally discovered mass in the right iliac fossa. The patient underwent active surveillance because a percutaneous biopsy revealed a mesenchymal neoplastic lesion of benign biological behavior. As the mass had high growth rates, a decision for open surgical exploration and excision was made. The pathology results indicated clear cell renal carcinoma, and negative results on 18F-FDG whole-body positron emission tomography-computed tomography (PET/CT) established the diagnosis of extra-renal clear cell RCC. Similar types of neoplasms are extremely rare and are estimated to have developed primarily in mesodermal embryonic remnants. Clinicians should be aware of this rare entity as its diagnosis is challenging and is based on pathology.

Case Report: Exceptional response to nivolumab plus cabozantinib in a patient with extrarenal clear cell renal cell carcinoma

Extrarenal clear cell renal cell carcinoma (eccRCC) is a rare type of RCC that arises in areas other than the kidney. Given its rarity, consensus guidelines for optimal treatment of eccRCC have not been established, and the literature is lacking any reports of patient response to systemic therapy and any reports of administration of immunotherapy to patients with ecRCC. Here, we present the case of a patient in their 60s with eccRCC arising in the spleen. The patient underwent splenic resection and then received systemic therapy, due to disease recurrence, with a combination of immunotherapy (IO) and tyrosine kinase inhibitor targeted therapy (VEGF-TKI). The patient had an excellent and durable response to this therapeutic regimen with minimal adverse effects, completing 2 years of therapy of nivolumab and cabozantinib. At the time of this report, the disease remains stable. This case demonstrates that combination therapy with IO+VEGF-TKI represents a reasonable and well-tolerated treatment option with activity in eccRCC and reveals interesting correlative data, including nests of stem-like CD8+T-cell infiltration in tumor tissue, which provide important biological context to this patient's exceptional therapeutic response.

Renal Cancer Without Primary Cancer in the Kidney: Extra-Renal TFE3 Translocation Associated Renal Cell Carcinoma

We report a case of an isolated para-aortic retroperitoneal renal cell carcinoma (RCC) in the absence of a primary cancer in the kidney. Single case reports in the literature have described extra-renal RCC in different locations with no evidence of primary renal tumor. We present the initial presentation, diagnostic imaging, surgical treatment, and pathologic evaluation. Immunohistochemistry demonstrated positivity for TFE3 and TFEB, both of which are Microphthalmia associated transcription factors (MiT) associated with translocation RCCs. We hypothesize these few cases of extra-renal RCC represent rare forms of translocation RCC.

Primary extrarenal papillary renal cell carcinoma presenting as a neck mass

Extrarenal primary renal cell carcinoma is an extremely rare entity with limited literature. Characteristic findings of renal cell carcinoma (RCC) at the metastatic site in the absence of a discrete radiological renal lesion can perplex both the clinician and pathologist. We report a case of metastatic primary extrarenal papillary RCC, who presented as a neck mass clinically and radiologically a paraaortic mass with normal bilateral native kidneys. The final diagnosis was aided by histopathological features, further confirmed by targeted immunohistochemical markers.

A huge extrarenal cell carcinoma developing from a heterotopic renal anlage with distant metastases: case report and literature review

Renal cell carcinoma (RCC) is the most common type of renal tumor arising from the proximal renal tubules. Extrarenal RCC is a rare case in which a tumor is found outside the kidney with no primary kidney tumor. Some theories suggest that these tumors arise from mesoderm remnant. Here, we present a unique case, the fourth in literature, of peri-renal, Extrarenal RCC case and the first case with a huge mass with distant metastases and aggressive progression.

Primary Extrarenal Type 2 Papillary Renal Cell Carcinoma: A Case Report

Type 2 papillary renal cell carcinoma (PRCC) is a malignant tumor originated from renal tubular epithelial cells. Here we present a rare case of extrarenal type 2 PRCC which is located at the right lateral side of the retroperitoneal inferior vena cava. No suspicious lesions were detected in the bilateral kidneys. The diagnosis was confirmed by histopathological examination after complete excision of the tumor. No recurrence was observed in 5 months of follow-up after surgery.