This case report represents the second documented robot-assisted resection of a primary renal neuroendocrine carcinoma (RNC). Owing to the rarity of the condition, a diagnosis of primary RNC is typically not highly considered during the initial workup of renal tumors. Primary upper tract urothelial carcinoma and renal cell carcinoma are more routinely considered given that these are the most common tumors of the kidney. Robot-assisted laparoscopic radical nephrectomy was selected after discussion with the patient. Following an uncomplicated surgical procedure, a histopathologic analysis confirmed primary RNC with lymph node metastases.
Radical nephrectomy with lymph node dissection for locally advanced disease is generally considered the treatment of choice for primary RNC. Due to the angioproliferative nature of primary neuroendocrine tumors of other origins, adjuvant treatment with vascular endothelial growth factor (VEGF) inhibitors such as sunitinib have been considered as well. We elected for close follow-up with imaging every four months given the paucity of data concerning treatment recommendations for this pathology. In contrast to the first documented case of robot-assisted resection of primary RNC which reported up to one month of follow-up, our case report discusses follow-up across a 48-month period. The patient demonstrated no evidence of disease until an MRI at 25-months identified several scattered sub-centimeter hypervascular nodules in the liver. The patient was followed expectantly until an MRI performed at 48-months identified a lesion in segment VIII of the liver that had increased in size from 3 to 7 mm, concerning for metastatic neuroendocrine carcinoma.
At the time of writing of this commentary, the patient is 54 months post-operation and continues to be monitored closely for further cancer progression. Given that the data supporting VEGF inhibitors is limited, the care team and patient elected to not proceed with this treatment modality. She remains asymptomatic at this time and the only indications that she has RNC metastases are the aforementioned imaging findings. Future research may identify a neoadjuvant antiangiogenic role for these medications in the setting of primary RNC.
Written by: Eric M. Lo, Baylor College of Medicine, Houston, Texas, USA
Authors: Ashwin Srivatsav, Adithya Balasubramanian, Jason Scovell, Wesley Mayer, Department of Urology, Baylor College of Medicine, Houston, Texas, USA
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