Owing to the aggressive course of Xp11 TRCC, she was referred to the medical oncology service for consideration of adjuvant chemotherapy or targeted therapy. Because of the lack of evidence for any benefit with these treatment modalities on this unique pathologic entity and no other foci of disease found on the patient’s postoperative

positron emission tomography-CT, adjuvant therapy was deferred to the time of possible future recurrence. Data regarding older adults are limited, and a review of the literature identified only 4 reports discussing Xp11 TRCC in patients older than 55 years, 5, 6, 7 and 8 as summarized in Table 1. However, Dabrafenib the incidence of this rare neoplasm may be underestimated with the true frequency unknown in patients older than 40 years because of its histologic features that often mimic clear cell and papillary RCC.9 Misdiagnoses may be further compounded by the fact that TFE3 immunohistochemistry and cytogenetic studies are not routinely done and there is significant histologic overlap with TFE3 negative buy PI3K Inhibitor Library and TFE3 positive RCC. Our case illustrates the importance of performing immunohistochemical analyses in suspicious cases, as the distinction of Xp11 TRCC is crucial in providing appropriate counseling and determining surveillance protocol and management. Cytogenetic analyses are another helpful modality to diagnose Xp11 TRCC and should be used

alongside immunohistochemistry. Despite the literature suggesting the propensity of adult Xp11 TRCC to progress rapidly, Cytidine deaminase 3 reports in adults older than 55 years with final pathologic stages pT1aN0Mx, pT1bN0Mx, and pT1bN2Mx disease found no evidence of disease at 24, 13, and 6 months, respectively.5, 6 and 7 The fourth case involved the oldest patient of 79 years with pT3a disease and multiple positive lymph nodes without distant metastasis.8 The patient underwent a radical nephrectomy without adjuvant chemotherapy but passed away approximately 44 days after

the operation from massive thrombosis of the portal vein. Our case presents an elderly patient with advanced T3aN1Mx disease, more consistent with the existing literature that suggests a relatively aggressive clinical course in adults. The patient was referred to medical oncology for evaluation of adjuvant chemotherapy, as there are emerging data suggesting efficacy of agents that target vascular endothelial growth factor and mammalian target of rapamycin pathways.10 These agents have been shown to have modest effects in the setting of metastatic disease and appear to be the optimal agents for management of metastatic Xp11 TRCC. Considering the rising incidence of RCC with the increased use of cross-sectional imaging, clinicians should be aware of Xp11 TRCC as a unique tumor and its propensity for rapid progression in adults to facilitate appropriate patient management.