Primitive Neuroectodermal Kidney Tumor in Adults. A Systematic Review

Introduction: Renal primitive neuroectodermal tumour (rPNET) is a rare entity, typically affecting young adults. The diagnosis is usually confirmed through histopathology. A multidisciplinary approach to treatment is essential due to its poor prognosis. Materials and Methods: A systematic literature review was conducted, and a descriptive analysis of significant variables from 128 cases is presented. Results and Discussion: The literature review indicated a slightly higher incidence in females (54.2%), with a mean age at presentation of 33 years (range: 16–73 years). The most common symptoms were acute flank pain (46%) and haematuria (33%). Tumour thrombus in the vena cava and metastatic dissemination were frequent (30.5% and 50.4%, respectively). In the systematic review, 98% of cases were cluster of differentiation 99 (CD99)-positive and 62.7% showed EWSR1 rearrangement. Nephrectomy was performed in 90% of cases, and 64.8% received adjuvant chemotherapy (CT). The mean follow-up was 24.8 months (range: 0.5–150 months). The median CSS was 11.5 months (interquartile range (IQR): 6–32.3), and the median OS was 9 months (IQR: 5.25–24). Conclusions: rPNET in adults is a rare, aggressive entity that is frequently diagnosed at an advanced stage. A multimodal strategy of surgery when feasible plus systemic multi-agent CT, with radiotherapy in selected cases, should be planned upfront in specialised centres by a multidisciplinary team.