Non-contrast imaging characteristics of papillary renal cell carcinoma: implications for diagnosis and subtyping.

INTRODUCTION: Current radiographic guidelines suggest unenhanced renal lesions < 20 Hounsfield Units (HU) are overwhelmingly benign, requiring no further evaluation. We evaluate our experience with papillary renal cell carcinoma (pRCC) presenting with low pre-contrast attenuation and the relationship of attenuation with histologic pRCC subtype. MATERIALS AND METHODS: We reviewed our institutional kidney cancer database for patients with pT1 or pT2 pRCC between 2003-2017. Tumors were categorized by papillary subtype by expert uropathologists. Preoperative CT images were analyzed at six regional tumor locations. Low, presumably benign, unenhanced median attenuation was defined as ≤ 20 HU. We calculated the frequency of pRCC with low attenuation and assessed the relationship between attenuation and pRCC subtype using logistic regression. RESULTS: Sixty-one patients with evaluable imaging were included. Median tumor size was 6 cm (1.7 cm-15.3 cm) with 39% (n = 24) type-1 and 61% (n = 37) type-2. Half of all pRCC tumors (n = 30) exhibited very low pre-contrast attenuation (< 20 HU), risking misdiagnosis as benign using current guidelines. Of these, 80% (n = 24) were type-2 with significant biological potential. Overall, type-2 tumors demonstrated a lower pre-contrast attenuation than type-1 (median HU: 19.8 (1.5-42.3) versus 29.6 HU (10-45.8), p < 0.01; max HU: 25.3 versus 36.5 HU, p < 0.01). After adjustment, lower pre-contrast HU was an independent predictor of pRCC subtype associated with a 5.5-fold increase of being type-2 (OR = 5.47, p < 0.01). CONCLUSION: pRCCs may exhibit very low attenuation on pre-contrast CT. This appears more common among the more aggressive type-2 subtype. These data suggest that low attenuation (< 20 HU) alone on non-contrast CT imaging is insufficient as a single parameter to rule out malignancy.

Renal Endometriosis: The Case of an Endometrial Implant Mimicking a Renal Mass.

Background: Endometriosis is a multifactorial benign disorder characterized by the abnormal presence of endometrial tissue in an extraendometrial site. Although extrapelvic endometriosis is uncommon, symptomatic involvement of the kidney is exceedingly rare. This benign disease can mimic several urologic processes, but because of its scarcity in clinical practice, it is seldom considered in the differential. Case Presentation: In this report, we describe the case of a 45-year-old woman with flank pain and hematuria, who was found to have a left renal mass on cross-sectional imaging. After robotic partial nephrectomy, pathologic analysis revealed an endometrial implant within the renal parenchyma. Conclusion: This case of renal endometriosis highlights how this benign disease process can mimic several more sinister urologic processes.

A review of lower urinary tract symptoms in patients with Parkinson's disease.

To critically review recent literature on lower urinary tract symptoms (LUTS) in patients with Parkinson's Disease.A literature search was conducted using the keywords LUTS, urinary symptoms, non-motor, and Parkinson's disease (PD) via the PubMed/Medline search engine. In the literature, we critically examined lower urinary symptoms in Parkinson's patients by analyzing prevalence, pathogenesis, urinary manifestations, pharmacologic trials and interventions, and prior review articles. The data collected ranged from 1986 to the present with an emphasis placed on recent publications.The literature regards LUTS in PD as a major comorbidity, especially with respect to a patient's quality of life. Parkinson's patients experience both storage and voiding difficulties. Storage symptoms, specifically overactive bladder, are markedly worse in patients with PD than in the general population. Surgical management of prostatic obstruction in PD can improve urinary symptoms. Multiple management options exist to alleviate storage LUTS in patients with PD, ranging from behavioral modification to surgery, and vary in efficacy.Lower urinary tract dysfunction in PD may be debilitating. Quality of life can be improved with a multi-pronged diagnosis-specific approach to treatment that takes into consideration a patient's ability to comply with treatment. A stepwise algorithm is presented and may be utilized by clinicians in managing LUTS in Parkinson's patients.