Renal angiomyolipoma (AML) is a typically benign renal tumor that is divided into 2 classes, the classical variant and the more aggressive epithelioid variant. It is extremely rare for an AML to exhibit aggressive features such as vascular invasion. We present the case of a 36-year-old female who presented with right lower quadrant pain for 9 months and was found to have an AML with tumor extension into the renal vein and the IVC. Diagnosis was confirmed with histopathology and the patient was treated with a total nephrectomy. The epithelioid subtype of AML is a rare variant that should be considered in the differential of a renal mass with vascular invasion.

Background: Variations in renal veins are quite common, and most people do not experience issues due to them. However, these variations are important for healthcare professionals, especially in surgical procedures and imaging studies, as precise knowledge of vascular anatomy is essential to avoid complications during medical interventions. The purpose of this study was to expose the frequency of anatomical variations in the renal vein (RV) and detail their relationship with the retroperitoneal and renal regions. Methods: A systematic search was conducted in the Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS databases from their inception until January 2024. Two authors independently carried out the search, study selection, and data extraction and assessed methodological quality using a quality assurance tool for anatomical studies (AQUA). Ultimately, consolidated prevalence was estimated using a random effects model. Results: In total, 91 studies meeting the eligibility criteria were identified. This study included 91 investigations with a total of 46,664 subjects; the meta-analysis encompassed 64 studies. The overall prevalence of multiple renal veins was 5%, with a confidence interval (CI) of 4% to 5%. The prevalence of the renal vein trajectory was 5%, with a CI of 4% to 5%. The prevalence of renal vein branching was 3%, with a CI of 0% to 6%. Lastly, the prevalence of unusual renal vein origin was 2%, with a CI of 1% to 4%. Conclusions: The analysis of these variants is crucial for both surgical clinical management and the treatment of patients with renal transplant and hemodialysis.

Nutcracker phenomenon (NCP) typically refers to the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. Similar to the classic NCP, the renal vein can also get entrapped between the segmental branches of the renal artery at the renal hilum, which has been referred to as \'renal hilar nutcracker phenomenon (RHNP).\' During routine dissection of a male cadaver of 67 years, the renal veins of both sides at the renal hilum were seen between the segmental branches of renal arteries, which we identified as the \'renal hilar nutcracker phenomenon.\' The disposition of the rest of the perihilar structures was normal. \'Renal hilar nutcracker phenomenon\' can have similar clinical presentation like that of the nutcracker phenomenon. Hence, knowledge of such anatomical variation at the renal hilum is desirable.
Terminu „spragtuko fenomenas“ įprastai apibūdinamas kairiosios inkstų venos įstrigimas tarp aortos ir viršutinės mezenterinės arterijos. Panašiai į klasikinį „spragtuko fenomeno“ atvejį, inkstų vena taip pat gali įstrigti ir tarp inkstų arterijos segmentinių atšakų ties inkstų sienelėmis. Šis reiškinys vadinamas inkstų hilariniu spragtuko fenomenu ir angliškai trumpinamas RHNP. Per 67 metų vyro lavono skrodimą buvo pastebėta, kad inkstų venos abiejose pusėse ties inkstų sienelėmis buvo išsidėsčiusios tarp inkstų arterijų segmentinių atšakų. Mes tai įvardijome „inkstų hilariniu spragtuko fenomenu“. Visos likusios perihilarinės struktūros išsidėstymas buvo normalus. Inkstų hilarinis spragtuko fenomenas kliniškai gali pasireikšti panašiai į spragtuko fenomeną. Todėl būtų naudinga įgyti daugiau žinių apie šią anatominę inkstų sienelių variaciją.

OBJECTIVE: Assess whether a Retroaortic left renal vein (RLRV) affects vertebral osteophyte formation in the lumbar spine, compared to normal anatomy left renal vein.
METHODS: We conducted a retrospective case-control study. Computed tomography (CT) scans of individuals with a RLRV (study group) were compared to age- and gender-matched normal anatomy CT scans (control group). L1 to L4 vertebral levels were appreciated for: left renal vein level, osteophyte presence and the aorta-vertebral distance (AVD) at the left renal vein level. Univariate analyses were conducted using Chi-square test and Fisher\'s test for categorical variables, and Student\'s t-test for continuous variables. Logistic regression was used for multivariate analyses.
RESULTS: A total of 240 patients were included in the study - equally distributed between the study and control groups. Normal anatomy left renal veins traversed the spine only at the L1 and L2 levels. RLRVs traversed the spine in all L1-L4 levels, mostly at the L3 and L2. Osteophyte prevalence at the level of left renal vein was significantly higher in the study group, compared with the control group [OR 2.54, P = 0.01]. Mean AVD was greater in the study group [9.2 mm ±3.6 mm Vs. 3.5 mm ± 2.6 mm, P < 0.001]. Increased AVD was found to be associated with a higher chance of osteophyte presence at the level of the left renal vein [OR 1.282, P = 0.025].
CONCLUSIONS: Osteophytes are more prevalent at the level of the RLRV variant compared to the normal anatomy. Furthermore, the RLRV is characterized by a lower lumbar level compared to the normal anatomy.
CONCLUSIONS: This anatomic variation could assist in further understanding of osteophyte formation.

To examine the prognostic significance of perinephric fat, renal sinus fat, and renal vein invasion in patients with pT3a renal cell carcinoma (RCC) by histologic type.
A population-based retrospective cohort study of patients with pT3aN0M0 RCC was performed using Surveillance, Epidemiology, and End Results (SEER) data for the years 2010 through 2019. Cox proportional hazards models were used to examine the relationship between pT3a subclassification groups and cancer-specific survival (CSS) by histological subtype (clear cell, papillary, chromophobe, and other).
The cohort consisted of 10,170 patients with pT3a RCC, including 8,446 (83.0%) with clear cell RCC and 1,724 (17.0%) with nonclear cell RCC (nccRCC). Median follow up was 36 months. Differences in CSS by pT3a subclassification groups were observed in all histological subtypes but were most pronounced in nccRCC, specifically papillary RCC. Compared to perinephric fat (PF) invasion only, renal vein (RV) invasion (HR = 4.9, 95%CI: 2.5-9.3, P < 0.01), renal sinus fat invasion (HR = 3.0, 95%CI: 1.4-6.2), RV and PF invasion (HR = 7.5, 95%CI: 3.5-16.0), and combination of all three characteristics (HR = 4.4, 95%CI: 1.2-15.5) were associated with worse CSS in patients with papillary RCC.
We examined the prognostic role of pT3a staging subclassifications in RCC by histologic subtype and observed survival differences, particularly in papillary RCC. Our findings highlight the need to refine pT3a staging criteria to help guide individualized, multimodal treatment strategies for locally advanced RCC.

The renal vein is an exceptional location for leiomyosarcoma, an aggressive malignant tumor of smooth-muscle origin with a poor prognosis. We report the case of a 55-year-old female patient who consulted for left flank pain that had been present for 6 months. A CT scan revealed a 9.4cm left retroperitoneal mass in contact with the psoas muscle, left kidney, stomach, spleen, left colon and extending up to the pancreas, raising the suspicion of a tumour originating in the retroperitoneal tissues. A biopsy revealed a smooth-muscle cell tumour with a degree of malignancy difficult to define. The patient underwent a monobloc left compartmentectomy, which led to the diagnosis of leiomyosarcoma of the left renal vein. A review of the literature on these rare tumours in this location is presented.

BACKGROUND: No consensus has been reached on operative procedures since a limited case series of robot-assisted inferior vena cava thrombectomy (RA-IVCT) and robot-assisted radical nephrectomy (RA-RN) have been described.
METHODS: The clinical data of 21 patients who underwent RA-IVCT and RA-RN were retrieved from the database. Preoperative preparation was used for assessment of the tumour. Surgical procedures were recorded, and operative skills were summarised.
RESULTS: The median IVC clamping time was 23 min, and IVC wall invasion was pathologically found in 2 cases. The mean postoperative hospital stay was 8.4 days and most patients recovered to full ambulation and oral feeding on the fourth day. None of the patients had liver or kidney dysfunction at the last follow-up (median, 24 months).
CONCLUSIONS: RA-IVCT presents technical challenges to surgeons. IVC control is an important part of the surgical process and different sides require different techniques.

Anatomic compression of the left renal vein in the angle between the aorta and superior mesenteric artery may be asymptomatic or may result in symptoms, including flank pain, hematuria, or pelvic pain and/or congestion. Patients can be referred to a vascular surgeon due to symptoms and/or radiologic findings. Because symptoms of nutcracker syndrome can be vague and/or nondiagnostic, careful evaluation, assessment, and counseling with patients are required before undertaking intervention, which is often an open surgical procedure. The definitive diagnosis is ideally confirmed with diagnostic venography, including pressure measurements from the left renal vein and inferior vena cava. The optimal treatment includes open decompression of the left renal vein with renal vein transposition or gonadal vein transposition, with or without concomitant management of pelvic varicosities if symptomatic. Because most patients with nutcracker syndrome are young, long-term follow-up with scheduled ultrasound examinations should be maintained.

Variations in the pattern of urogenital vessels can arise as a single occurrence or as a combination, which may increase the risk of unexpected injury during surgical procedures. Multiple variations in the renal and testicular vessels, in a novel combination, were observed during dissection of an 87-year-old Japanese male cadaver. In the present case, the patient had two renal arteries on each side. On the right side, the superior and inferior renal arteries emerged from the abdominal aorta at the L1 and L4 vertebrae levels, respectively. On the left side, the superior renal artery originated from the abdominal aorta at the level of the L1/L2 intervertebral disc, whereas the inferior renal artery arose at L4. The right testicular artery emerged from the abdominal aorta at the level of the L2 vertebra and crossed the inferior vena cava posteriorly. The venous system also exhibited some variations. The left renal vein passed posteriorly to the abdominal aorta and opened into the inferior vena cava at the level of the L2 vertebra. On the course to the inferior vena cava, the left renal vein was connected only to the first lumbar, azygos, and hemiazygos veins; blood was not collected from the left testicular and suprarenal veins, which usually open to the left renal vein. The patient had two right testicular veins. The lateral one opened into the angle between the right renal vein and the inferior vena cava at the level of the L2 vertebra, and the medial one drained into the inferior vena cava at a level slightly lower than the lateral one. Knowledge of the possible anatomical variations may be beneficial for performing safe retroperitoneal surgery and understanding the development of these vessels.

BACKGROUND: Para-aortic lymphadenectomy is an essential part of gynecologic oncologic surgical treatment. The surgeon should be aware of the complex usual anatomy and its common variants.
METHODS: Between January 2021 and May 2023, 58 women underwent para-aortic lymphadenectomy for gynecologic malignancies.
RESULTS: Vascular and urinary tract anatomic variants were retrospectively reviewed from the prospective institutional database and results were compared with preoperative contrast-enhanced abdominal CT. Of these 58 women, 47 women had no vascular or urinary tract variants. One woman had a double inferior vena cava, two patients were found to have a retro-aortic left renal vein, four had accessory renal arteries, two had a double left ureter, one had a ptotic kidney in the iliac fossa, and one patient had bilateral kidney malrotation. Anatomic variants in the preoperative CT were described by a radiologist in only two patients, and additional vascular and urinary tract variants were found incidentally at the time of surgery.
CONCLUSIONS: Acknowledgment of vascular and urinary tract variants is helpful for the surgeon to establish an appropriate surgical plan and to avoid iatrogenic surgical trauma.