High-grade carcinomas involving the renal sinus: report of a case and review of the differential diagnosis and immunohistochemical expression

Urothelial carcinoma of the renal pelvis with renal vein and inferior vena cava tumor thrombus: case series and literature review

Background

Urothelial carcinoma (UC) of the renal pelvis with renal vein and inferior vena cava (IVC) tumor thrombus (TT) was extremely rare. We aimed to explore the clinical and pathological characteristics, diagnosis and treatment of renal pelvis UC with renal vein and IVC TT.

Methods

From March 2016 to January 2019, eight patients of renal pelvis UC with renal vein and IVC TT were diagnosed and underwent operation in our hospital. Clinical features, operative details, pathological outcomes, and prognosis data were reviewed and collected.

Results

There were five males and three females (52-84 years old). Their main symptoms were flank pain and hematuria. According to the Mayo classification, the TT was 4 level-0 (1 left and 3 right), 2 level-I (right), and 2 level-II (right). Half the patients underwent retroperitoneal laparoscopic radical nephroureterectomy with thrombectomy, and the other underwent open procedures. The mean operative time was 298.9 minutes. Pathological outcomes revealed high-grade UC, with positive lymph nodes in 6 cases. Four patients received adjuvant chemotherapy, one target therapy and one adjuvant chemotherapy combined with immunotherapy after surgery. The mean follow-up time was 11.1 months. Three patients are alive, and two of them developed recurrence and lung metastasis.

Conclusions

Preoperative differentiation between renal pelvis UC and renal cell carcinoma with venous TT was very important for the management. Radical nephroureterectomy with thrombectomy might be a reasonable method for renal pelvis UC with venous TT. The prognosis of such cases was poor even if adjuvant therapy was scheduled.

The Differential Diagnosis of Medullary-Based Renal Masses

CONTEXT.—

Renal malignancies can be divided into cortical- and medullary-based tumors, the latter of which classically infiltrate the renal parenchyma by extending between nonneoplastic structures. Although high-grade cortical tumors can rarely exhibit the same growth pattern, the infiltrative morphology should elicit a differential diagnosis to be considered in each case. However, these diagnoses can be challenging to distinguish, especially on small renal biopsy samples.

OBJECTIVE.—

To provide an overview of the clinical, gross, and microscopic findings; genetic and molecular alterations; and immunohistochemical evaluation of medullary-based renal tumors and other tumor types with overlapping morphologies and growth patterns.

DATA SOURCES.—

Literature review and personal observations were used to compile the information in this review.

CONCLUSIONS.—

Collecting duct carcinoma is a prototypical medullary-based tumor, and although diagnostic criteria exist, it remains a diagnosis of exclusion, especially with ancillary techniques aiding the recognition of established as well as more recently described neoplasms. Other medullary-based malignancies included in the differential diagnosis include renal medullary carcinoma/renal cell carcinoma unclassified with medullary phenotype, fumarate hydratase-deficient renal cell carcinoma, and upper tract urothelial carcinoma. Moreover, other rare entities should be excluded, including metastatic carcinoma, lymphoma, and melanoma. In addition to potential prognostic differences, accurate diagnoses can have important surgical and clinical management implications.

Renal Medullary Carcinoma

Renal medullary carcinoma, also referred to as the seventh sickle cell nephropathy, typically affects young African Americans with sickle cell trait, or, less frequently, patients with sickle cell disease. The existence of renal medullary carcinoma without a concomitant hemoglobinopathy is a topic of controversy. The typical patient is a young male of African or Mediterranean descent, with hematuria and/or flank pain. Most patients have metastatic disease at the time of presentation. The tumor is characteristically a poorly circumscribed mass in the medullary region, commonly showing variable amounts of hemorrhage and necrosis. Microscopically, a characteristic reticular or cribriform pattern with a striking desmoplastic stromal response and a robust mixed inflammatory infiltrate is observed. Collecting duct carcinoma, malignant rhabdoid tumor, urothelial carcinoma, and other subtypes of renal cell carcinoma are in the differential diagnosis. Because of the advanced stage of disease at presentation and the aggressive nature of this malignant neoplasm, survival is poor even with chemotherapy; however, isolated reports of prolonged survival have been documented.

Renal solitary fibrous tumor/hemangiopericytoma: computed tomography findings and clinicopathologic features

PURPOSE

To retrospectively characterize the clinical, pathological, and computed tomography (CT) findings of renal solitary fibrous tumor/hemangiopericytoma (rSFT/HPC).

METHODS

Twelve patients with rSFT/HPCs were enrolled. The CT findings and clinicopathological features were retrospectively reviewed.

RESULTS

This study included six male and six female patients (median age: 47; age range: 20-82 years). Eight benign (grade I) and four malignant (grade III) rSFT/HPCs were identified. Of the 12 lesions, 10 were in the renal sinus near the renal pelvis, while two replaced the whole kidney. Five lesions were well-defined, five were partially ill-defined, and two were ill-defined. Mild (5/12) and intermediate (1/12) hydronephrosis was observed. On the unenhanced CT images, ten tumors showed slightly higher density when compared to the normal renal parenchyma, and two masses were isodense to hypodense. After intravenous contrast medium injection, three enhancement patterns were observed, including "prolonged enhancement" (PE) (6/12), "gradual enhancement" (4/12), and "early washout" (2/12). A central fibrous scar was found in five patients. Compared to the grade I lesions, the grade III rSFT/HPC lesions tended to be larger (maximal diameter > 10 cm) and more heterogeneous with a higher incidence of the PE pattern.

CONCLUSIONS

We have shown that rSFT/HPCs usually arise from the renal sinus, and present as lobulated, slightly hyperdense, gradually enhancing soft tissue masses. CT findings, including large size, heterogeneity, and the PE pattern, may assist in the pre-operative identification of malignant grade III rSFT/HPCs.

S100P as a Marker for Urothelial Histogenesis: A Critical Review and Comparison With Novel and Traditional Urothelial Immunohistochemical Markers

S100P, or placental S100, is a member of a large family of S100 proteins and considered to be a promising immunohistochemical marker to support urothelial differentiation. This review synthesizes published data regarding the expression of S100P in urothelial carcinoma across histological grade and variant patterns, and in other malignancies, in an effort to summarize the state of understanding of this marker and evaluate its potential. We provide also a broad comparison of S100P with other contemporary and traditional urothelial markers and outline the potential utility of S100P in various diagnostically challenging scenarios. Taken in context, we recommend that to provide immunohistochemical support for consideration of urothelial differentiation, S100P may be included in a panel of markers (due to its high sensitivity), with better established (GATA3) and more specific (uroplakin 2) markers, for comparison with corresponding markers of other primary sites under consideration, depending on the clinical context. We emphasize that the overall most appropriate panel for any given case depends on the differential diagnosis engendered by the morphology encountered, and the constellation of clinical findings. As always with immunohistochemical panels, expected positive and negative markers for each diagnostic consideration should be included. Finally, since as of date there are no optimally sensitive or specific markers of urothelial differentiation, all final diagnoses relying on immunohistochemical support should be made in the appropriate clinical and histological context.

Renal Medullary Carcinoma; A Rare Entity

Renal medullary carcinoma (RMC) is an uncommon aggressive neoplasm of the kidney. RMC is biologically aggressive with a very poor prognosis, and metastasis is seen in up to 95% of the patients at diagnosis or shortly thereafter. The common sites of metastasis are respectively lymph nodes, lungs, livers, and adrenal glands in order of frequency. The presence of poorly differentiated eosinophilic cells in a characteristic fibro-inflammatory stroma is seen in histological examination. The origin and pathogenesis of RMC are unclear. The radiographical and pathological findings suggest that RMC probably originates in the calyceal epithelium in or near the renal papillae, which could be the result of chronic ischemic damage in the renal papillae epithelium by sickled erythrocytes. Positivity of VEGF and HIF-1α supports the chronic hypoxia that may be caused in the pathogenesis of RMC. Other factors such as genetic or environmental factors are important. Although hemoglobinopathy is very common, RMC is very rare. An understanding of the molecular and genetic factors of this rare disease is important for its prevention and treatment. We herein describe an adult Turkish patient, who presented with hematuria. The diagnosis was RMC after pathological examination.

Morphologic, Molecular, and Taxonomic Evolution of Renal Cell Carcinoma: A Conceptual Perspective With Emphasis on Updates to the 2016 World Health Organization Classification

Molecular and morphologic interrogation has driven a much-needed reexamination of renal cell carcinoma (RCC). Indeed, the recently released 2016 World Health Organization classification now recognizes 12 distinct RCC subtypes, as well as several other emerging/provisional RCC entities. From a clinical perspective, accurate RCC classification may have important implications for patients and their families, including prognostic risk stratification, targeted therapeutics selection, and identification for genetic testing. In this review, we provide a conceptual framework for approaching RCC diagnosis and classification by categorizing RCCs as tumors with clear cytoplasm, papillary architecture, and eosinophilic (oncocytic) cytoplasm. The currently recognized 2016 World Health Organization classification for RCC subtypes is briefly discussed, including new diagnostic entities (clear cell papillary RCC, hereditary leiomyomatosis and RCC-associated RCC, succinate dehydrogenase-deficient RCC, tubulocystic RCC, and acquired cystic disease-associated RCC) and areas of evolving RCC classification, such as transcription elongation factor B subunit 1 (TCEB1)-mutated RCC/RCC with angioleiomyoma-like stroma/RCC with leiomyomatous stroma, RCC associated with anaplastic lymphoma receptor tyrosine kinase (ALK) gene rearrangement, thyroidlike follicular RCC, and RCC in neuroblastoma survivors. For each RCC subtype, relevant clinical, molecular, gross, and microscopic findings are reviewed, and ancillary studies helpful for its differential diagnosis are presented, providing a practical approach to modern RCC classification.

Transitional cell carcinoma with extension of the renal vein and IVC tumor thrombus: report of three cases and literature review

Background

Transitional cell carcinoma (TCC) originating from the renal pelvis with a venous tumor thrombus is a rare entity. However, clinicians should be aware of it because of its high malignancy and poor prognosis.

Case presentation

Here, we report three cases of pathologically confirmed TCC originating from the renal pelvis with extension into the renal vein or inferior vena cava (IVC). Of these patients, two are males and one is female (58~73 years old). Their main symptom is flank pain; besides, gross hematuria and weight loss is observed in one of the patients. Computed tomography (CT) scan of the first patient revealed multiple space-occupying lesions in the left renal pelvis and left medium and lower ureter with a tumor thrombus in the left renal vein. CT scan of the second patient revealed a right renal mass and extension into the IVC. Abdominal magnetic resonance imaging (MRI) of the third patient showed a soft tissue mass in the region of the left renal sinus, and the signal of the soft tissue was observed in the left renal vein. The preoperative diagnoses of the first and third patient were TCC, while the second patient was renal cell carcinoma (RCC). Two patients with the preoperative diagnosis of TCC underwent laparoscopic radical nephroureterectomy with thrombectomy, and the other patient underwent radical nephrectomy with thrombectomy. The surgeries were successful. Although two of our patients underwent chemotherapy and radiotherapy, they died 2 and 19 months after the surgery, respectively. The other patient refused any adjuvant therapy and died 3 months after the operation.

Conclusions

Compared to the extension of RCC to the renal vein or IVC, extension of TCC to the renal vein or IVC is rare. TCC with a venous tumor thrombus is often misdiagnosed as RCC. However, a correct preoperative or intraoperative diagnosis is of great importance to decide surgical strategy. Laparoscopic radical nephroureterectomy with thrombectomy may be a safe and feasible operative method in treatment of TCC with a renal vein thrombus. The prognosis of such cases is poor even if chemotherapy and radiotherapy are scheduled.

MiT Family Translocation-Associated Renal Cell Carcinoma: A Contemporary Update With Emphasis on Morphologic, Immunophenotypic, and Molecular Mimics

Translocation-associated renal cell carcinoma (t-RCC) is a relatively uncommon subtype of renal cell carcinoma characterized by recurrent gene rearrangements involving the TFE3 or TFEB loci. TFE3 and TFEB are members of the microphthalmia transcription factor (MiT) family, which regulates differentiation in melanocytes and osteoclasts, and MiT family gene fusions activate unique molecular programs that can be detected immunohistochemically. Although the overall clinical behavior of t-RCC is variable, emerging molecular data suggest the possibility of targeted approaches to advanced disease. Thus, distinguishing t-RCC from its morphologic, immunophenotypic, and molecular mimics may have important clinical implications. The differential diagnosis for t-RCC includes a variety of common renal neoplasms, particularly those demonstrating clear cell and papillary features; in addition, because of immunophenotypic overlap and/or shared molecular abnormalities (ie, TFE3 gene rearrangement), a distinctive set of nonepithelial renal tumors may also warrant consideration. Directed ancillary testing is an essential aspect to the workup of t-RCC cases and may include a panel of immunohistochemical stains, such as PAX8, pancytokeratins, epithelial membrane antigen, carbonic anhydrase IX, HMB-45, and Melan-A. Dual-color, break-apart fluorescent in situ hybridization for TFE3 or TFEB gene rearrangement may be helpful in diagnostically challenging cases or when molecular confirmation is needed.

Primary carcinoma of renal calyx

Renal calyx carcinoma (RCXC) may mimic collecting duct carcinoma (CDC) or urothelial carcinoma (UC) of the renal pelvis. RCXC is distinguished from CDC and UC of the renal pelvis as having the tumor epicenter in the renal calyx, with limited involvement of the surrounding renal pelvis surface urothelium. In this study, we summarize our experience with this entity. Ten cases of RCXC, including 9 cases with urothelial differentiation (RCXC-UC) and 1 case with salivary gland-type differentiation (RCXC-SC), were identified. Ten consecutive cases of UC were selected for comparison, with extensive renal pelvis involvement and with secondary renal parenchymal invasion. Two cases of collecting duct carcinoma (CDC) were also examined. Immunohistochemistry (IHC) was performed on representative tissue blocks for PAX8, PAX2, CK5, CK7, CK20, p63, GATA3, AMACR, RCC, CD10, vimentin, S100, and MSA. The 10 cases of RCXC (M:F=4:6, ages: 62-91 years, mean: 76) presented with renal masses of 3-6cm. Ureteroscopic studies and renal pelvic washings showed atypical/malignant cells in three cases. Seven patients were treated with nephrectomy followed by radiation±chemotherapy, and all cases developed metastases to lymph nodes or liver/lung/bone. In all 7 cases with nephrectomy, there was extensive renal parenchymal involvement with infiltrating borders and diffuse spread along collecting ducts. Six RCXC-UC contained focal squamous differentiation. The RCXC-SC displayed features of adenoid cystic and basaloid features. In situ UC, with or without papillary components, was identified in the calyces in all 7 nephrectomy cases with remaining renal pelvis harboring small tumor burden in 5 cases, and no tumor in another 2 cases. Of the three cases without nephrectomy, no tumor in the renal pelvis could be visualized with endoscopy, however one case was associated with UC of the urinary bladder. Of 10 control UC cases, tumor was limited to the tip of renal papilla in 7 cases, extensive in 3 cases, and with no extension into the collecting ducts. RCXC-UC were all positive for p63, CK5, CK7, and PAX2, with all negative for RCC. PAX8 (70% positive) and GATA3 (50% positive) reactivity was variable. The 10 UC cases shared IHC properties with RCXC-UC but frequent negativity for PAX8 and positivity for GATA3. RCXC is an aggressive neoplasm with high risk of metastases. Similar to CDC, it is located in the renal papilla and rarely with clinically visible renal pelvis tumor or ureteral urine positive for tumor cells. Unlike CDC and non-calyceal UC, RCXC shows predominantly urothelial and squamous differentiation and is associated with an in situ component of adjacent renal calyces. By IHC, RCXC exhibited features intermediate between UC and CDC with decreased or negative immunoreactivity for PAX8 and GATA.