Hormone receptor conversion in metastatic breast cancer.

Background/Objective: Hormone receptor (HR) status is one of the key factors in determining the treatment of breast cancer. Previous studies suggested that HR status may change in metastatic tissue. However, available studies focused mainly on primary biopsies and there are only few trials comparing HR status in the primary tumour and the metastasis using material from complete resection. The aim of the study was to determine the frequency of HR alterations in metastatic breast cancer. Materials and methods: The study retrospectively examines a total of 50 patients who underwent brain, lung, or liver metastasectomy for metastatic breast cancer between January 2000 and January 2019. Results: HR conversion was observed in a total of 30 cases (60.0%), while HER-2/neu (human epidermal growth factor receptor 2) discrepancy surprisingly occurred only in one case (2.0%). A change in immunophenotype occurred in 28% of cases. Triple-negativity was more frequent in brain metastases (p = 0.039). Conclusions: We have confirmed that HR conversion between the primary tumour and its metastases occurs in a significant number of cases, which has important implications for further treatment decisions.

Mutation Profile Variability in the Primary Tumor and Multiple Pulmonary Metastases of Clear Cell Renal Cell Carcinoma. A Review of the Literature and Analysis of Four Metastatic Cases.

(1) Background: There are limited data concerning inter-tumoral and inter-metastatic heterogeneity in clear cell renal cell carcinoma (CCRCC). The aim of our study was to review published data and to examine mutation profile variability in primary and multiple pulmonary metastases (PMs) in our cohort of four patients with metastatic CCRCC. (2) Methods: Four patients were enrolled in this study. The clinical characteristics, types of surgeries, histopathologic results, immunohistochemical and genetic evaluations of corresponding primary tumor and PMs, and follow-up data were recorded. (3) Results: In our series, the most commonly mutated genes were those in the canonically dysregulated VHL pathway, which were detected in both primary tumors and corresponding metastasis. There were genetic profile differences between primary and metastatic tumors, as well as among particular metastases in one patient. (4) Conclusions: CCRCC shows heterogeneity between the primary tumor and its metastasis. Such mutational changes may be responsible for suboptimal treatment outcomes in targeted therapy settings.

The Role of Serum Tumor Markers in Follow-up After Surgical Treatment of Malignant Lung Tumors.

AIM: The aim of this study was to evaluate the utility of selected tumor markers for the detection of lung cancer recurrence during follow-up. PATIENTS AND METHODS: The study group consisted of 109 patients and 109 healthy controls. The following biomarkers were selected: Carcinoembryonic antigen; cytokeratin fragment 19; neuron-specific enolase; tissue polypeptide-specific antigen; cytokeratin fragments 8, 18 and 19; insulin-like growth factor 1; pro-gastrin-releasing peptide; and 25-hydroxyvitamin D. The biomarkers were assessed individually or using a multivariate analysis. RESULTS: Carcinoembryonic antigen [area under the receiver operating characteristics curve (AUC)=0.6857, p<0.0001] and cytokeratin fragment 19 (AUC=0.6882, p<0.0001) proved best in detecting relapse. The multivariate model indicated insulin-like growth factor 1 (p=0.0006, AUC=0.6225) as the third most useful biomarker. The multivariate model using these three markers achieved the best AUC value of 0.7730 (p=0.0050). CONCLUSION: We demonstrated that carcinoembryonic antigen and cytokeratin fragment 19 play a key role in the detection of lung cancer recurrence. A multivariate approach can increase the effectiveness of detection.

Prognostic Factors After Surgical Treatment of Liver Metastases from Breast Cancer - 19 Years of Experience.

BACKGROUND/AIM: The aim of this study was to determine the importance of surgical treatment, utility of hormone receptor status and selected biomarkers in the prognosis of patients with liver metastases from breast cancer (BCLM). PATIENTS AND METHODS: Thirty female underwent surgery for BCLM between 1/2000 and 1/2019. RESULTS: The type of surgery (resection/radiofrequency ablation) had no impact on overall survival (OS) - (p=0.894). Having more than one BCLM (p=0.003), expression of human epidermal receptor 2 in metastases (p=0.034), as well as an elevated presurgical level of carbohydrate antigen 19-9 (p=0.017) and postsurgical thymidine kinase (p=0.034) were negative prognostics factor for recurrence-free survival. The factors affecting OS included the number of liver procedures (p=0.021), the degree of proliferative activity (p=0.008) and elevated postsurgical carcinoembryonic antigen level (p=0.038). CONCLUSION: The type of surgery had no impact on OS. Markers and hormonal status of liver metastases are important factors affecting prognosis.

Outcomes and Prognostic Factors Following Surgical Treatment of Pulmonary Metastases from Colorectal Carcinoma.

BACKGROUND/AIM: The lungs are the second most common site of cancer dissemination. The aim of this study was to analyze a cohort of patients operated for pulmonary metastases from colorectal carcinoma over a period of 18 years. PATIENTS AND METHODS: In a group of 104 patients, relations were sought between overall survival or disease-free survival and preoperative levels of selected biomarkers, number of metastases and the condition of the intrathoracic lymphatic nodes. Median observation period was 63 months. RESULTS: The 5-year survival rate was 54.3%. Risk of disease progression and risk of death increases in case of occurrence of 2 or more metastases, affection of intrathoracic lymph nodes and levels of CA 19-9, TPS or CEA above cut-off value. CONCLUSION: Prognostic factors that determine overall survival as well as disease-free survival are the number of metastases, the condition of intrathoracic lymphatic nodes and the preoperative levels of biomarkers.

Prognostic Significance of Lymph Node Examination by the OSNA Method in Lung Cancer Patients-Comparison with the Standard Histopathological Procedure.

The aim of the study was to compare the prognostic significance of lymph node status of patients with lung cancer analyzed by three different methods: hematoxylin and eosin (H&E), immunohistochemistry of cytokeratin 19 (IHC CK19), and One-Step Nucleic Acid Amplification (OSNA). The clinical relevance of the results was evaluated based on relation to prognosis; the disease-free interval (DFI) and overall survival (OS) were analyzed. During radical surgical treatment, a total of 1426 lymph nodes were obtained from 100 patients, creating 472 groups of nodes (4-5 groups per patient) and examined by H&E, IHC CK19 and OSNA. The median follow-up was 44 months. Concordant results on the lymph node status of the H&E, IHC CK19 and OSNA examinations were reported in 78% of patients. We recorded shorter OS in patients with positive results provided by both OSNA and H&E. The study demonstrated a higher percentage of detected micrometastases in lymph nodes by the OSNA method. However, the higher sensitivity of the OSNA, with the cut-off value 250 copies of mRNA of CK19/µL, resulted in a lower association of OSNA positivity with progress of the disease compared to H&E. Increasing the cut-off to 615 copies resulted in an increase in concordance between the OSNA and H&E, which means that the higher cut-off is more relevant in the case of lung tumors.

Long-term Results of Surgery for Colorectal Liver Metastases in Terms of Primary Tumour Location and Clinical Risk Factors.

BACKGROUND/AIM: The aim of the study was to evaluate the influence of primary tumour location and clinical risk factors for long-term results of surgery for colorectal liver metastases (CLMs). PATIENTS AND METHODS: Overall survival (OS) and recurrence-free survival (RFS) were evaluated in 636 patients. Patients were divided by tumour location (right-/left-sided colorectal cancer: RCRC/LCRC; rectal cancer), and age, gender, number and size of CLMs, type of liver surgery and interval from primary operation were evaluated. RESULTS: One-, 3- and 5-year OS and RFS were independent of primary tumour location (p<0.59). CLM diameter was negatively associated with OS for the whole cohort (p<0.002), and RCRC (p<0.03) and LCRC (p<0.04) groups, as well as for RFS of those with LCRC (p<0.04). CLM number was negatively associated with RFS for the whole cohort (p<0.0001), RCRC (p<0.02), LCRC (p<0.0001) and RC (p<0.02). Radiofrequency ablation and combined procedures led to worse OS for the whole cohort (p<0.03), and to worse RFS for the whole cohort (p<0.0003) and for those with LCRC (p<0.03). A shorter interval between primary colorectal cancer surgery and CLMs procedure was risky for poor OS and RFS of patients with CLMs from RCRC (p<0.05), LCRC (p<0.05) and RC (p<0.02). CONCLUSION: Primary tumour location together with clinical risk factors are important for long-term results of surgery CLMs.

Pros and Cons of Portal Vein Embolization With Hematopoietic Stem Cells Application in Colorectal Liver Metastases Surgery.

BACKGROUND/AIM: Portal vein embolization (PVE) with autologous stem cells application (aHSC) is a method for future liver remnant volume (FLRV) increase. The aim of the study was to evaluate the positivite and negativite aspects of the method in clinical practice. PATIENTS AND METHODS: PVE with aHSC application was used in 32 patients with colorectal liver metastases and insufficient FLRV. Preoperative number of colorectal liver metastases (CLMs) was 5.2±3.6, CLMs volume 70.1±102.3 mm3 Results: FLRV growth occurred after 2-3 weeks in 31 (96.9%) patients, with volume increase from 528.2±170.5 to 715.4±143.3 ml (p=0.0001). Postoperative thirty days mortality, morbidity was 0% and 3.1%, respectively. Insufficient FLRV growth occurred in one patient. R0 liver resection was performed in 27(87.1%) patients. CLMs volume progression was in 5 (15.6%) patients from 680.0±59.4 to 723.1±57.1 ml (p=0.01). One and two-year overall survival were 88% and 62.9% respectively. Six and twelve-month recurrence-free survival rates were 50.7% and 39.6% respectively. CONCLUSION: PVE with aHSC application is a safe and useful method for FLRV growth. It significantly increases secondary CLMs resectability. However, it can cause CLMs progression. Liver resection should, therefore, be performed as soon as possible after achieving optimal increase of FLRV.

External validation of a postoperative nomogram for the prediction of disease-specific survival in patients with papillary renal cell carcinoma using a large multicenter database.

PURPOSE: Based on data retrieved from a comprehensive multicenter database, we externally validated a published postoperative nomogram for the prediction of disease-specific survival (DSS) in patients with papillary renal cell carcinoma (papRCC). METHODS: A multicenter database containing data of 2325 patients with surgically treated papRCC was used as validation cohort. After exclusion of patients with missing data and patients included in the development cohort, 1372 patients were included in the final analysis. DSS-probabilities according to the nomogram were calculated and compared to actual DSS-probabilities. Subsequently, calibration plots and decision curve analyses were applied. RESULTS: The median follow-up was 38 months (IQR 11.8-80.7). Median DSS was not reached. The c-index of the nomogram was 0.71 (95% CI 0.60-0.83). A sensitivity analysis including only patients operated after 1998 delivered a c-index of 0.84 (95% CI 0.77-0.92). Calibration plots showed slight underestimation of nomogram-predicted DSS in probability ranges below 90%: median nomogram-predicted 5-year DSS in the range below 90% was 55% (IQR 20-80), but the median actual 5-year DSS in the same group was 58% (95% CI 52-65). Decision-curve analysis showed a positive net-benefit for probability ranges between a DSS probability of 5% and 85%. CONCLUSIONS: The nomogram performance was satisfactory for almost all DSS probabilities; hence it can be recommended for application in clinical routine and for counseling of patients with papRCC.

Outcomes for Patients after Resection of Pulmonary Metastases from Clear Cell Renal Cell Carcinoma: 18 Years of Experience.

INTRODUCTION: Clear cell renal cell carcinoma (ccRCC) is the most common kidney tumor. If feasible, metastasectomy is preferably indicated in metastatic disease. OBJECTIVE: The aim of this study was to determine the outcome of patients after pulmonary metastasectomy (PM). METHODS: PM for ccRCC was performed in 35 patients in the period of January 2001-2019. Clinical characteristics, type of surgery, histopathology results, and follow-up data were recorded. Progression-free survival (PFS) after PM and overall survival (OS) were defined as outcome endpoints. RESULTS: A total of 77 PMs were performed in 35 patients after nephrectomy for ccRCC. The mean size of pulmonary metastasis was 19.0 mm (4-90). With a median follow-up after PM of 79.2 months, the 3- and 5-year OS rates were 63.5 and 44.9%, respectively. The only statistically significant prognostic factor affecting both PFS (p = 0.019) and OS (p = 0.015) was the dimension of pulmonary metastases. CONCLUSIONS: The prognosis of metastatic ccRCC is generally poor, particularly in cases of larger size of metastasis. PM might improve the individual prognosis of patients with lung metastasis even in cases with higher number of metastases, bilaterality, synchronous metastasis, or a short progression-free interval after nephrectomy.

Rete Testis Invasion Is Consistent With Pathologic Stage T1 in Germ Cell Tumors.

OBJECTIVES: Rete testis invasion by germ cell tumors is frequently concomitant with lymphovascular or spermatic cord invasion (LVI/SCI); independent implications for staging are uncertain. METHODS: In total, 171 seminomas and 178 nonseminomatous germ cell tumors (NSGCTs; 46 had 1%-60% seminoma component) came from five institutions. Metastatic status at presentation, as a proxy for severity, was available for all; relapse data were unavailable for 152. Rete direct invasion (ReteD) and rete pagetoid spread (ReteP) were assessed. RESULTS: ReteP and ReteD were more frequent in seminoma than NSGCT. In seminoma, tumor size bifurcated at 3 cm or more or less than 3 cm predicted metastatic status. Tumors with ReteP or ReteD did not differ in size from those without invasions but were less than with LVI/SCI; metastatic status or relapse did not show differences. In NSGCT, ReteP/ReteD did not correlate with size, metastatic status, or relapse. CONCLUSIONS: Findings support retaining American Joint Committee for Cancer pathologic T1 stage designation for rete testis invasion and pT1a/pT1b substaging of seminoma.

"High-grade oncocytic renal tumor": morphologic, immunohistochemical, and molecular genetic study of 14 cases.

The spectrum of the renal oncocytic tumors has been expanded in recent years to include several novel and emerging entities. We describe a cohort of novel, hitherto unrecognized and morphologically distinct high-grade oncocytic tumors (HOT), currently diagnosed as "unclassified" in the WHO classification. We identified 14 HOT by searching multiple institutional archives. Morphologic, immunohistochemical (IHC), molecular genetic, and molecular karyotyping studies were performed to investigate these tumors. The patients included 3 men and 11 women, with age range from 25 to 73 years (median 50, mean 49 years). Tumor size ranged from 1.5 to 7.0 cm in the greatest dimension (median 3, mean 3.4 cm). The tumors were all pT1 stage. Microscopically, they showed nested to solid growth, and focal tubulocystic architecture. The neoplastic cells were uniform with voluminous oncocytic cytoplasm. Prominent intracytoplasmic vacuoles were frequently seen, but no irregular (raisinoid) nuclei or perinuclear halos were present. All tumors demonstrated prominent nucleoli (WHO/ISUP grade 3 equivalent). Nine of 14 cases were positive for CD117 and cytokeratin (CK) 7 was either negative or only focally positive in of 6/14 cases. All tumors were positive for AE1-AE3, CK18, PAX 8, antimitochondrial antigen, and SDHB. Cathepsin K was positive in 13/14 cases and CD10 was positive in 12/13 cases. All cases were negative for TFE3, HMB45, Melan-A. No TFEB and TFE3 genes rearrangement was found in analyzable cases. By array CGH, complete chromosomal losses or gains were not found in any of the cases, and 3/9 cases showed absence of any abnormalities. Chromosomal losses were detected on chromosome 19 (4/9), 3 with losses of the short arm (p) and 1 with losses of both arms (p and q). Loss of chromosome 1 was found in 3/9 cases; gain of 5q was found in 1/9 cases. On molecular karyotyping, 3/3 evaluated cases showed loss of heterozygosity (LOH) on 16p11.2-11.1 and 2/3 cases showed LOH at 7q31.31. Copy number (CN) losses were found at 7q11.21 (3/3), Xp11.21 (3/3), Xp11.22-11.21 (3/3), and Xq24-25 (2/3). CN gains were found at 13q34 (2/3). Ten patients with available follow up information were alive and without disease progression, after a mean follow-up of 28 months (1 to 112 months). HOT is a tumor with unique morphology and its IHC profile appears mostly consistent. HOT should be considered as an emerging renal entity because it does not meet the diagnostic criteria for other recognized eosinophilic renal tumors, such as oncocytoma, chromophobe renal cell carcinoma (RCC), TFE3 and TFEB RCC, SDH-deficient RCC, and eosinophilic solid and cystic RCC.

Cystic Appearance on Imaging Methods (Bosniak III-IV) in Histologically Confirmed Papillary Renal Cell Carcinoma is Mainly Characteristic of Papillary Renal Cell Carcinoma Type 1 and Might Predict a Relatively Indolent Behavior of Papillary Renal Cell Carcinoma.

AIM: The aim of this study was to determine the proportion of cystic tumors according to preoperative CT (Bosniak III, IV) among surgically treated patients with histologically confirmed papillary renal cell carcinoma (pRCC) and to assess progression rates among patients with and without cystic appearance on imaging. METHODS: A total of 138 patients with pRCC histology surgically treated in the period of January 2007-March 2017 were included. Clinical and radiological characteristics, type of surgery, histopathology results, and follow-up data were recorded and statistically evaluated. RESULTS: Forty-one cases (29.7%) of cystic lesions (10× BIIF, 14× BIII, 17× BIV) were detected by CT. Patients with pRCC1 significantly more frequently presented with cystic appearance on CT (33/78; 42.3%) in comparison to other papillary types (8/60; 13.3%; p = 0.0002). During a median follow-up time of 49.4 months, only 2 patients with cystic lesions progressed after surgery. CONCLUSIONS: Cystic appearance on imaging methods is mainly a characteristic of pRCC1 (42.3%). Cystic morphology on imaging might predict a relatively indolent behavior of all pRCC types. Preoperative scoring systems including tumor growth patterns (cystic vs. solid) are needed for further classification.

Papillary renal cell carcinoma with cytologic and molecular genetic features overlapping with renal oncocytoma: Analysis of 10 cases.

BACKGROUND: We present a series of papillary renal cell carcinomas (PRCC) reminiscent of so-called "oncocytic variant of papillary renal cell carcinoma" (OPRCC), included in the 2016 WHO classification as a potential type 3 PRCC. OPRCC is a poorly understood entity, cytologically characterized by oncocytic cells with non-overlapping low grade nuclei. OPRCC is not genotypically distinct and the studies concerning this variant have shown an inconsistent genetic profile. The tumors presented herein demonstrated predominantly papillary/tubulopapillary architecture and differed from OPRCC by pseudostratification and grade 2-3 nuclei (Fuhrman/ISUP). Because there is a morphologic overlap between renal oncocytoma (RO) and PRCC in the cases included in this study, the most frequently affected chromosomes in RO and PRCC were analyzed. MATERIALS AND METHODS: 147 PRCC composed of oncocytic cells were retrieved from our registry in order to select a group of morphologically uniform tumors. 10 cases with predominantly papillary, tubulopapillary or solid architectural patterns were identified. For immunohistochemical analysis, the following antibodies were used: vimentin, antimitochondrial antigene (MIA), AMACR, PAX8, CK7, CK20, AE1-3, CAM5.2, OSCAR, Cathepsin K, HMB45, SDHB, CD10, and CD117. Enumeration changes of locus 1p36, chromosomes 7, 14, 17, X, Y and rearrangement of CCND1 were examined by FISH. For further study, only tumors showing karyotype similar to that of RO were selected. The tumors exhibiting either trisomy of chromosomes 7, 17 or gain of Y, thus abnormalities characteristic for PRCC, were excluded. RESULTS: There were 5 males and 5 females, with patient age ranging from 56 to 79 years (mean 66.8 years). The tumor size ranged from 2 to 10 cm (mean 5.1 cm). Follow-up was available for 8/10 patients (mean 5.2 years); one patient died of the disease, while 7 of 8 are alive and well. Immunohistochemically, all cases were reactive for AMACR, vimentin, PAX8, OSCAR, CAM5.2, and MIA. SDHB was retained in all cases. 9/10 cases were positive for CD10, 7/10 cases reacted with CK7, 4/10 with Cathepsin K, and 2/10 with AE1-3. None of the cases were positive for CD117, HMB45 and CK20. All 10 cases were analyzable by FISH and showed chromosomal abnormalities similar to that usually seen in RO (i.e. loss of 1p36 gene loci, loss of chromosome Y, rearrangement of CCND1 and numerical changes of chromosome 14). CONCLUSIONS: We analyzed a series of renal tumors combining the features of PRCC/OPRCC and RO, that included pseudostratification and mostly high grade oncocytic cells lining papillary/tubulopapillary structures, karyotype characterized by loss of 1p36, loss of chromosome Y, rearrangement of CCND1 gene and numerical changes of chromosome 14. Despite the chromosomal numerical abnormalities typical of RO, we classified these tumors as part of the spectrum of PRCC because of their predominant papillary/tubulopapillary architecture, immunoprofile that included reactivity for AMACR, vimentin and lack of reactivity for CD117, all of which is incompatible with the diagnosis of RO. This study expands the morphological spectrum of PRCC by adding a cohort of diagnostically challenging cases, which may be potentially aggressive.

Magnetic resonance imaging as an adjunct diagnostic tool in computed tomography defined Bosniak IIF-III renal cysts: a multicenter study.

INTRODUCTION: CT imaging is the standard examination for renal cystic lesions and defines the Bosniak category, which dictates further management. Given that Bosniak II/IIF/III renal cystic lesions can potentially harbor renal cell carcinoma (RCC), additional diagnostic modalities may be required in management decision making. AIM: To determine the value of additional magnetic resonance imaging in CT-defined Bosniak IIF-III renal cystic lesions. MATERIALS AND METHODS: This a multicenter retrospective study of 46 consecutive patients, diagnosed with cystic renal lesions between 2009 and 2016. The inclusion criteria were: (1) cystic renal lesion classified as Bosniak IIF-III on CT, (2) a subsequent MRI examination, and (3) documented outcome via surgery for cystic renal mass or follow-up. RESULTS: 46 patients (35 males, 11 females) were included. The mean size of the cystic lesion was 3.92 cm (0.7-10 cm). According to the CT findings, Bosniak IIF and III were found in 12 (26.1%) and 34 (73.9%) cases. Reclassification of Bosniak category was done after MRI examination in 31 cases (67.4%). An upgrade rate of 58.7% (27 cases) to a higher category was made, while the downgrade rate to a lower category was achieved in 4 cases (8.7%). As a result, significant therapeutic management change was made in 12/31 patients (38.7%), of whom 8 underwent subsequent surgery. CONCLUSION: MRI study may reduce the use of Bosniak IIF category (in comparison with CT), which has a direct impact on therapeutic management (surgery vs. surveillance) in a significant proportion of patients.

Low-grade spindle cell proliferation in clear cell renal cell carcinoma is unlikely to be an initial step in sarcomatoid differentiation.

AIMS: Spindle cell proliferation within clear cell renal cell carcinoma (ccRCC) is usually considered as a sarcomatoid differentiation. Low-grade spindle cell proliferation (LG-SCP) in ccRCC was first described in 2001. This phenomenon is not common and can pose diagnostic challenges, particularly in core biopsies. The aim of this study was to describe morphological, immunohistochemical and molecular characteristics of ccRCCs with LG-SCP. METHODS AND RESULTS: Eleven cases of ccRCC with LG-SCP were retrieved from approximately 21 000 renal tumours in our registry. Ten cases of conventional ccRCC and 10 cases of typical sarcomatoid ccRCC were included as control groups. Morphological and immunohistochemical characteristics of epithelial-mesenchymal transition (EMT) were analysed. Von Hippel-Lindau syndrome gene abnormalities were also analysed using molecular genetics. Among ccRCC with LG-SCP cases, there were five males and five females (clinical information was not available in one case) with a median age of 67 years (mean: 68.5, range: 60-81 years). Average tumour size was 7.1 cm (median:7.5, range:1.7-12 cm). Follow-up data were available in nine cases (mean: 44.78 months), with no aggressive behaviour seen. On average, LG-SCP areas constituted 5-80% of tumour volume (mean: 32.3%). Necrotic/regressed areas were seen in all cases ranging from 5% to 30%. LG-SCP was clearly epithelial, with no mitoses or any evidence of mesenchymal differentiation. Immunohistochemical profile of LG-SCP was consistent with 'conventional' ccRCC. Compared with sarcomatoid ccRCC, some EMT markers showed alteration in LG-SCP, including lower expression of N-cadherin and Zeb1 as well as higher expression of E-cadherin. However, there were no significant differences in EMT markers between LG-SCP and conventional ccRCC. Abnormalities in VHL (mutations, LOH3p) were found in six of 11 cases. CONCLUSIONS: Our findings showed that LG-SCP in ccRCC have comparable immunohistochemical and molecular characteristics to those seen in 'conventional' ccRCC. Further, immunohistochemical analysis of EMT markers showed that LG-SCP did not differ from 'conventional' ccRCC. We believe that LG-SCP is a part of morphological heterogeneity in ccRCCs and that they may not represent an initial stage of sarcomatoid differentiation. This is supported further by the fact that ccRCC with LG-SCP did not display more aggressive behaviour than 'conventional' ccRCC.

High-grade renal cell carcinoma with emperipolesis: Clinicopathological, immunohistochemical and molecular-genetic analysis of 14 cases.

Emperipolesis has recently been described as a constant feature of "biphasic squamoid" papillary renal cell carcinoma (BPRCC). We also noticed this in some high-grade (HG) RCC, which promoted the present study to estimate the incidence of emperipolesis in RCCs and to describe them in further detail. 14 cases of HGRCC showing emperipolesis were retrieved from our registry. Microscopic examination of filed slides was supplemented with immunohistochemical and molecular-genetic analyses using paraffin embedded tissue. 12 of 14 patients were males with a mean age of 58.6 years (range 41-72 years). Tumor size ranged from 6-16.5 cm (mean of 8.8 cm). Follow up data were available for 8/14 patients (range 0.5-10 years). Metastases were documented in 6 cases. All tumors showed solid-alveolar growth patterns with focal pseudopapillary features, and were composed of large cells with bizarre nuclei and eosinophilic rhabdoid-like cytoplasm. Emperipolesis was a constant and prominent feature in large bizarre cells. All cases were positive for OSCAR, CANH 9, vimentin, cyclin D1, INI-1, and myoD1, while negative for melanocytic markers, CK 7, myoglobin, cathepsin K, and TFE3. VHL gene abnormalities were found in 6/9 analyzable cases, of which 2 demonstrated polysomy of chromosomes 7, 17. Emperipolesis is a rare histomorphologic feature which can be seen not only in BPRCCs but also in highgrade CCRCCs. All RCC cases with prominent emperipolesis fulfilled both morphologic and immunohistochemical diagnostic criteria of high-grade CCRCC. The majority of patients with available follow up information developed metastases.

Cystic and necrotic papillary renal cell carcinoma: prognosis, morphology, immunohistochemical, and molecular-genetic profile of 10 cases.

Conflicting data have been published on the prognostic significance of tumor necrosis in papillary renal cell carcinoma (PRCC). Although the presence of necrosis is generally considered an adverse prognostic feature in PRCC, we report a cohort of 10 morphologically distinct cystic and extensively necrotic PRCC with favorable biological behavior. Ten cases of type 1 PRCC with a uniform morphologic pattern were selected from the 19 500 renal tumors, of which 1311 were PRCCs in our registry. We focused on precise morphologic diagnosis supported by immunohistochemical and molecular-genetic analysis. Patients included 8 men and 2 women with an age range of 32-85 years (mean, 62.6 years). Tumor size ranged from 6 to 14 cm (mean, 9.4 cm). Follow-up data were available in 7 patients, ranging from 0.5 to 14 years (mean, 4 years). All tumors were spherical, cystic, and circumscribed by a thick fibrous capsule, filled with hemorrhagic/necrotic contents. Limited viable neoplastic tissue was present only as a thin rim in the inner surface of the cyst wall, consistent with type 1 PRCC. All cases were positive for AMACR, OSCAR, CAM 5.2, HIF-2, and vimentin. Chromosome 7 and 17 polysomy was found in 5 of 9 analyzable cases, 2 cases demonstrated chromosome 7 and 17 disomy, and 1 case showed only chromosome 17 polysomy. Loss of chromosome Y was found in 5 cases, including 1 case with disomic chromosomes 7 and 17. No VHL gene abnormalities were found. Papillary renal cell carcinoma type 1 can present as a large hemorrhagic/necrotic unicystic lesion with a thick fibroleiomyomatous capsule. Most cases showed a chromosomal numerical aberration pattern characteristic of PRCC. All tumors followed a nonaggressive clinical course. Large liquefactive necrosis should not necessarily be considered an adverse prognostic feature, particularly in a subset of type 1 PRCC with unilocular cysts filled with necrotic/hemorrhagic material.

Morphological Characterization of Papillary Renal Cell Carcinoma Type 1, the Efficiency of Its Surgical Treatment.

AIM: Papillary renal cell carcinoma type 1 (pRCC1) represents the second most common type of malignant renal epithelial tumour. The origin of its characteristic appearance, its growth mechanism, and the long-term efficiency of its surgical treatment remain uncertain. Our aim was to determine typical characteristics of surgically treated pRCC1. METHODS: pRCC1 was verified in 83 of 1,629 (5.1%) kidney tumours surgically treated in the period of January 2007-January 2016. The clinical and radiological characteristics, type of surgery, histopathology results and follow up data were recorded. Spearman correlation, Kruskal-Wallis analysis of variance, Fisher's exact, and chi-square test were used to analyse appropriate variables. The overall survival rate was evaluated using the Gehan-Wilcoxon test and the Cox proportional hazards model. RESULTS: The mean tumour size was 52.0 mm (15-180); 98.8% of the tumours showed a spherical shape and in 82.1%, exophytic growth was observed. Partial nephrectomy was performed in 80.7%. A majority (81.9%) were classified as pT1. Tumours, 89.2% of them, belonged to Fuhrman grade 1 or 2. The mean follow-up was 46.8 months. The overall survival was associated with pT category (p ≤ 0.0001). CONCLUSIONS: Typical signs of pRCC1 are a spherical shape, exophytic growth and low Fuhrman's grade. More than three-fourths of pRCC1 could be treated by the nephron-sparing surgery.

Morphological, immunohistochemical, and chromosomal analysis of multicystic chromophobe renal cell carcinoma, an architecturally unusual challenging variant.

Chromophobe renal cell carcinoma (ChRCC) is typically composed of large leaf-like cells and smaller eosinophilic cells arranged in a solid-alveolar pattern. Eosinophilic, adenomatoid/pigmented, or neuroendocrine variants have also been described. We collected 10 cases of ChRCC with a distinct multicystic pattern out of 733 ChRCCs from our registry, and subsequently analyzed these by morphology, immunohistochemistry, and array comparative genomic hybridization. Of the 10 patients, 6 were males with an age range of 50-89 years (mean 68, median 69). Tumor size ranged between 1.2 and 20 cm (mean 5.32, median 3). Clinical follow-up was available for seven patients, ranging 1-19 years (mean 7.2, median 2.5). No aggressive behavior was documented. We observed two growth patterns, which were similar in all tumors: (1) variable-sized cysts, resembling multilocular cystic neoplasm of low malignant potential and (2) compressed cystic and tubular pattern with slit-like spaces. Raisinoid nuclei were consistently present while necrosis was absent in all cases. Half of the cases showed eosinophilic/oncocytic cytology, deposits of pigment (lipochrome) and microcalcifications. The other half was composed of pale or mixed cell populations. Immunostains for epithelial membrane antigen (EMA), CK7, OSCAR, CD117, parvalbumin, MIA, and Pax 8 were positive in all tumors while negative for vimentin, TFE3, CANH 9, HMB45, cathepsin K, and AMACR. Ki67 immunostain was positive in up to 1 % of neoplastic cells. Molecular genetic examination revealed multiple chromosomal losses in two fifths analyzable tumors, while three cases showed no chromosomal numerical aberrations. ChRCC are rarely arranged in a prominent multicystic pattern, which is probably an extreme form of the microcystic adenomatoid pigmented variant of ChRCC. The spectrum of tumors entering the differential diagnosis of ChRCC is quite different from that of conventional ChRCC. The immunophenotype of ChRCC is identical with that of conventional ChRCC. Chromosomal numerical aberration pattern was variable; no chromosomal numerical aberrations were found in three cases. All the cases in this series have shown an indolent and non-aggressive behavior.