LAUSR

To the Editor: These authors performed creative research and report the interesting finding that intraoperative rupture of cystic renal tumors is relatively common but has few oncologic implications. After reading the full article we believe that readers may misinterpret the results and should view the findings and conclusions with caution. Unfortunately this report may result in urologists not giving enough attention to preventing cyst rupture intraoperatively, and neglecting the potential risk of malignant tumors after cyst rupture and failing to provide subsequent appropriate treatment, which could have catastrophic consequences in some patients. As stated in the article, fluid spillage from a ruptured cyst may not increase the risk of local recurrence. However, cystic renal tumors and renal neoplastic cysts are usually difficult to differentiate, and neoplastic cysts may occur in some rare but highly malignant renal tumors. For example renal medullary carcinoma as well as hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC) associated renal cancer may present with cystic elements. Swartz et al found that 3 of 28 renal medullary carcinomas contained cysts, while Merino et al observed that 16 of 40 and 5 of 40 HLRCC kidney tumors, respectively, presented with cystic areas and predominantly cystic elements. These findings may be due to Fh1 deficiency, as germline mutations in the Fh1 gene predispose to HLRCC and renal cysts. These 2 types of tumors are extremely malignant and have a poor prognosis. Current research on these extremely malignant tumors is lacking and, although the risk of local recurrence and distant metastasis is unknown, once these cystic lesions rupture it is unimaginable that these risks would not increase. The authors did not have patients with these rare malignant cancer types and they overlooked proper interpretation in this study. If readers credit this article, they may think that if a cyst ruptures it will not have a significant impact on oncologic outcomes, and thus they may not take sufficient precautions to avoid cystic rupture. Cyst rupture unfortunately occurs, and the rare types are confirmed by pathological examination. However, readers may be unaware that these patients need to be followed closely, with possible reoperation consisting of expanded partial or even radical nephrectomy and/or combined adjuvant targeted therapy, which may be critical for these individuals.