Case Of Metanephric Adenoma Research Articles

KANK1-NTRK3 fusions define a subset of BRAF mutation negative renal metanephric adenomas

BackgroundMetanephric adenoma (MA) is a rare benign renal neoplasm. On occasion, MA can be difficult to differentiate from renal malignancies such as papillary renal cell carcinoma in adults and Wilms̕ tumor in children. Despite recent advancements in tumor genomics, there is limited data available regarding the genetic alterations characteristic of MA. The purpose of this study is to determine the frequency of metanephric adenoma cases exhibiting cytogenetic aberration t (9;15)(p24;q24), and to investigate the association between t (9,15) and BRAF mutation in metanephric adenoma.MethodsThis study was conducted on 28 archival formalin fixed paraffin-embedded (FFPE) specimens from patients with pathologically confirmed MA. Tissue blocks were selected for BRAF sequencing and fluorescent in situ hybridization (FISH) analysis for chromosomal rearrangement between KANK1 on chromosome 9 (9p24.3) and NTRK3 on chromosome 15 (15q25.3), which was previously characterized and described in two MA cases.ResultsBRAFV600E mutation was identified in 62% of our cases, 9 (38%) cases were BRAFWT, and 4 cases were uninformative. Of the 20 tumors with FISH results, two (10%) were positive for KANK1-NTRK3 fusion. Both cases were BRAFWT suggesting mutual exclusivity of BRAFV600E and KANK1-NTRK3 fusion, the first such observation in the literature.ConclusionsOur data shows that BRAF mutation in MA may not be as frequent as suggested in the literature and KANK-NTRK3 fusions may account for a subset of BRAFWT cases in younger patients. FISH analysis for KANK1-NTRK3 fusion or conventional cytogenetic analysis may be warranted to establish the diagnosis of MA in morphologically and immunohistochemically ambiguous MA cases lacking BRAF mutations.

Analysis of imaging and pathological features of renal neoplasms among different pathological types

Objective To compare the different pathological type of renal tumor, clinical epidemiology, imaging and pathological features, summarize its value in the diagnosis of renal tumor. Methods The clinical data of 2198 patients who underwent surgical treatment in our hospital due to renal tumors from January 2010 to January 2019 were retrospectively analyzed. There were 1 404 males and 794 females with an average age of (56.5±11.7) years old. The clinical epidemiology, image features and pathological features were compared. Results Among them, the pathological results concluded 1 891 cases of renal clear cell carcinoma (86.0%), 112 cases of papillary renal cell carcinoma (5.1%), 76 cases of chromophobe cell carcinoma (3.5%), 23 cases of multilocular cystic renal tumors with low malignant potential (1.0%), 13 cases of Xp11.2 translocation carcinoma (0.6%), 4 cases of collecting duct carcinoma (0.2%), 58 cases of anadipotic angiomyolipoma (2.6%), 18 cases of acidophiloma (0.8%), and 3 cases of metanephric adenoma (0.1%). The overall differences in age and gender among patients with renal tumors of different pathological types were statistically significant (F=13.8, P 0.05). No significant difference in the distribution of left and right side, the clinical manifestations were mainly sporadic(χ2=19.63, P>0.05). The results of renal tumors ultrasound ith different pathological types showed statistically significant difference (χ2=67.1, P<0.05). Hyperechoic (20, 34.5%) and mixed echogenicity (16, 27.6%) were the main manifestations of lipoma. Multilocular cystic renal tumors with low malignant potential were mostly cystic and solid mixed echogenicity (14, 60.9%). CT values of renal tumors of different pathological types at all stages showed statistically significant differences (P<0.05). The CT values of clear cell carcinoma at the arterial phase of CT enhanced scan were significantly higher than those of other types of tumors (F=11.6, P<0.05), but decreased significantly in the parenchymal phase, showing the characteristics of in and fast out . The CT values of papillary cell carcinoma in the third phase of enhanced scan were all lower than those of clear cell carcinoma and chromophobe cell carcinoma (P<0.05), showing a progressive enhancement . The effect of chromophobe cell carcinoma is somewhere in between. The CT value on plain scan of anadipotic angiomyolipoma was higher than that of clear cell carcinoma, and the was followed by continuous enhancement, showing the characteristics of in and slow out . The majority of clear cell carcinoma and papillary cell carcinoma were tan section (1 235, 72.55%; 51, 52.13%). The grey-white section was the most common type of adipogenic angiomyolipoma (21, 40.4%). Conclusions The epidemiological characteristics, imaging and pathological features of renal tumors of different pathological types have certain characteristics, especially the enhanced CT features of renal clear cell carcinoma, papillary renal cell carcinoma, chromophobe cell carcinoma and anadipotic angiomyolipoma, which are of certain value for the differential diagnosis of renal tumors of different pathological types. Key words: Renal tumors; Different pathological types; Imaging; Pathology

Novel clinicopathological and molecular characterization of metanephric adenoma: a study of 28 cases

BackgroundMetanephric adenoma is a rare, benign renal neoplasm with occasional misdiagnosis. However, its molecular characterization is not fully understood.MethodsIn this study, we use the hybrid capture-based Next-Generation Sequencing to sequence a panel of 295 well-established oncogene or tumor suppressor genes in 28 cases of MA patients in China. Novel clinicopathological markers associated with the mitogen-activated protein kinase (MAPK) pathway in metanephric adenoma were detected by immunohistochemistry.ResultsIt was found that except for BRAF (22/28) mutations (c.1799 T > A, p.V600E), NF1 (6/28), NOTCH1 (5/28), SPEN (5/28), AKT2 (4/28), APC (4/28), ATRX (3/28), and ETV4 (3/28) mutations could also be detected. Meanwhile, a novel and rare gene fusion of STARD9-BRAF, CUX1-BRAF, and LOC100507389-BRAF was detected in one MA patient. In addition, although MEK phosphorylation was normally activated, the phosphorylation level of ERK was low in metanephric adenoma cases. Highly expressed p16 and DUSP6 may have contributed to these results, which maintained MA as a benign renal tumor.ConclusionsThis study provides novel molecular and pathological markers for metanephric adenoma, which could improve its diagnosis and increase the understanding of its pathologic mechanism.

METANEPHRIC ADENOMA DIAGNOSED PREOPERATIVELY AS RENAL CELL CARCINOMA: A REPORT OF TWO CASES.

Metanephric adenoma is an extremely rare benign tumor. We report two cases of metanephric adenoma that were diagnosed preoperatively as renal cell carcinoma (RCC).Case 1 was a right renal tumor found by ultrasonography in a 57-year old woman who presented for a medical examination. Abdominal CT revealed a 26-mm mass that was enhanced weakly in the early phase and enhanced strongly in the late phase, in the right kidney. Based on a clinical diagnosis of RCC (cT1aN0M0), laparoscopic partial nephrectomy was performed. Case 2 was a left renal tumor incidentally found during an annual examination of a 79-year old woman with a past history of breast cancer. Abdominal CT revealed a 24-mm mass that was enhanced heterogeneously in the left kidney. Based on a clinical diagnosis of RCC (cT1aN0M0), laparoscopic radical nephrectomy was performed. The pathological diagnosis of both cases was metanephric adenoma.It is often difficult to distinguish metanephric adenoma from other malignant neoplasms preoperatively. When it is difficult to distinguish between renal cell carcinoma and metanephric adenoma, renal tumor biopsy and minimal surgery is required.

The value of diagnosing kidney neoplasms with 18 F-FDG PET/CT

Objective To explore the clinical diagnostic value of 18 F-FDG PET/CT in patients with kidney neoplasms.Methods Seventy-nine patients (52 males,27 females,average age (57.3 ± 14.1) years),who had definitive diagnosis of kidney neoplasms by 18F-FDG PET/CT and pathological or clinical comprehensive diagnosis in recent five years,were analyzed retrospectively.The diagnosis by PET/CT was made according to the changes of kidney shape,tumor density and FDG uptake (SUVmax).The diagnostic efficacy was calculated.Results Among the 79 patients,70 cases were finally diagnosed as malignant tumors (including 40 cases of renal cell carcinoma,5 cases of renal pelvis carcinoma,8 cases of lymphoma,16 cases of metastatic tumor,and 1 case of renal fascia capsule liposarcoma) and 9 cases of benign tumors (including 7 cases of angiomyolipomas,1 case of renal acidophilic cell adenoma,1 case of metanephric adenoma; the benign tumors did not contain small lipid sample hamartoma cases).The detective rate of kidney neoplasms with 18F-FDG PET/CT was 97.5％ (77/79).For the identification of benign and malignant lesions,the sensitivity of 18F-FDG PET/CT was 92.9％ (65/70),specificity was 7/9,accuracy was 91.1％ (72/79),positive predictive value was 97.0％ (65/67),and negative predictive value was 58.3 ％ (7/12).Conclusions 18 F-FDG PET/CT can detect and identify most of kidney tumors.Whole-body checking and comprehensive evaluation on kidney cancer patients are still the main advantages of PET/CT. Key words: Kidney neoplasms ; Tomography, emission-computed; Tomography, X-ray computed; Deoxyglucose

PAX2 Expression in Wilms Tumors and Other Childhood Neoplasms

PAX2 plays an important role in kidney development; although small studies have demonstrated PAX2 expression in Wilms tumors (WT), comprehensive studies on formalin-fixed tissue are lacking. Thus, we systematically evaluated PAX2 immunohistochemical staining in a retrospective study of pediatric WT, as compared with other pediatric tumors. We stained formalin-fixed, paraffin-embedded sections from 39 WT, 6 nephrogenic rests, 8 non-Wilms renal tumors, and 43 nonrenal pediatric small round cell tumors with 2 different PAX2 polyclonal antibodies. PAX2 demonstrated strong, diffuse staining of epithelial and blastema components of WT (97% of cases). PAX2 stained WT stroma in fewer cases (23%), but 80% of anaplastic foci were positive. Nephrogenic rests, 1 case of metanephric adenoma, and 1 pediatric renal cell carcinoma were also PAX2 positive; other pediatric renal tumors were negative. Neuroblastoma, primitive neuroectodermal tumor/Ewings, and T-cell acute lymphoblastic lymphoma (ALL) were PAX2 negative. However, PAX2 weakly stained some cases of B-cell ALL rhabdomyosarcoma (RMS) was also stained, especially alveolar RMS (83%), with less staining of embryonal RMS (13%). One of the antibodies also stained maturing myoid cytoplasm of WT and RMS. This study shows that PAX2 is a sensitive marker of WT (sensitivity 97%), but PAX2 shows weak-to-moderate-intensity nuclear staining of RMS and B-cell ALL, somewhat limiting its utility. However, PAX2 may be a helpful marker in certain diagnostic situations. We speculate that RMS and B-cell ALL staining could be due to antibody cross-reactivity with PAX family members with known expression in RMS and B-cell ALL.

Detection of chromosome copy number alterations in metanephric adenomas by array comparative genomic hybridization

Metanephric adenoma is a rare benign renal tumor typically found in adults. Previous cytogenetic analyses, including karyotyping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization, have yielded conflicting results regarding the somatic genetic aberrations of these tumors. In this study, we investigated the genomic profile of nine cases of metanephric adenoma using array comparative genomic hybridization. Two cases revealed multiple chromosomal gains and losses. Three cases showed sporadic chromosomal imbalances involving no more than three chromosomes. Four cases showed normal chromosome copy numbers. The gain of chromosome 19 was the most common finding (five cases), and FISH using 19p and 19q telomeric probes further confirmed this finding. We did not observe consistent gains of chromosomes 7 and 17, which are common in papillary renal cell carcinoma, neither did we find chromosomal alterations frequently present in Wilms' tumors, including chromosome gains of 1q, 7q, and 12, and losses of 11p and 16q. Our series demonstrates that the genetic profile of metanephric adenoma is fundamentally distinct from those of papillary renal cell carcinoma and Wilms' tumor.

Adenoma metanéfrico renal de predominio quístico: A propósito de un caso

Metanephric adenoma is a relatively unfrequent asymptomatic embryogenic renal tumor which is generally diagnosed by an abdominal diagnostic tests indicated for other reasons. Differential diagnosis with benign and malignant tumors has to be performed.We report one case of metanephric adenoma with intense necrotic-hemorrhagic and cystic changes with a size not previously referred in the literature.Cystic and hemorrhagic changes in benign renal tumors make differential diagnosis with malignant tumors mandatory Surgery is necessary in almost all cases and histologic study will give the diagnosis.

Metanephric adenoma of the kidney: Ultrastructural, immunohistochemical and lectin histochemical studies

A case of metanephric adenoma, a rare benign tumor of the kidney is reported, and the results of ultrastructural, immunohistochemical, and lectin histochemical studies are presented. The patient was a 47 year old Japanese man presenting with a left renal tumor by ultrasonography. The nephrectomy material revealed a well-demarcated tumor with medullary appearance, and on histological examination the tumor was composed of cuboidal cells forming regular small tubules with hyalinous stroma. Incomplete glomeruloid structures were formed in a few elongated tubules composed of columnar cells. Metanephric blastema was not observed in the tumor or in the normal kidney. By electron microscope, the tumor cells were observed to be immature cells with microvilli at the apical surfaces. The neoplastic tubules were surrounded by basal lamina. The tumor cells were immunoreactive for Leu 7, epithelial membrane antigen, vimentin, and low molecular weight cytokeratin, and were weakly immunoreactive for S-100 protein. Peanut agglutinin, soybean agglutinin, and Dolichos biflorus agglutinin were bound to the apical surfaces of the tumor cells.