神經內分泌腎臟腫瘤-案例報告

楊宗道^1,2*，張景欣^1,2,3

陽明交通大學微免所, 臺北醫學大學附設醫院泌尿科,臺北醫學大學泌尿腎臟研究中心

Neuroendocrine renal tumor-case report

Tzung-Dau, Yang^1,2* , Ching-Hsin, Chang^1,2,3

1.Department of Urology, Taipei Medical University Hospital, Taipei, 11031, Taiwan

2.TMU Research Center of Urology and Kidney, Taipei Medical University, Taipei, 11031, Taiwan

3.Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.

Case report:

This 43-year-old female patient had a history of hypertension that had been effectively managed for two years under medical control. During a routine health check-up, a renal sonography revealed a left renal tumor characterized by a mixed echoic lesion measuring 3.2cm in size. Subsequently, she was referred to our Nephrology and Urology outpatient department for further evaluation. In December of the previous year, a CT scan and MRI revealed the presence of a soft tissue mass within the upper pole of the left kidney, which was more centrally located and causing hydronephrosis. Upon reviewing her medical records, it was noted that she had experienced hypokalemia with a potassium level of 3.2mEq/L. Additionally, an elevated 24-hour urine VMA of 9.05mg/24hr was observed. Given the clinical impression of renal cell carcinoma (RCC), the patient underwent laparoscopic left nephrectomy in July. Importantly, no significant changes in blood pressure were detected during the surgical procedure.

However, the pathology report revealed that the tumor was, in fact, a well-differentiated neuroendocrine tumor. Microscopically, the renal tumor exhibited a well-differentiated neuroendocrine pattern, with arrangements in insular, ribbon-like, and trabecular patterns. The tumor cells displayed finely granular chromatin patterns and a substantial amount of eosinophilic cytoplasm. Focal cystic changes were also noted. Immunohistochemical staining showed that the tumor was diffusely positive for synaptophysin and INSM-1, weakly focally positive for CK and chromogranin A, and negative for PAX8, WT-1, BRAF (V600E), and CK7. The Ki-67 proliferative index was found to be less than 5%.

The patient recovered well from the surgical procedure, and her systolic blood pressure remained stable. The dosage of medication for hypertension was not reduced post-surgery. Furthermore, no local recurrence was detected in the post-operative imaging studies conducted at the 3-month follow-up.

It is worth noting that neuroendocrine tumors are relatively rare, particularly within the urinary tract. Most neuroendocrine tumors in the urinary tract are typically found in the prostate. In addition to functional adrenal tumors, we should place increased emphasis on monitoring blood pressure peri-operatively in cases like this.