Anaplastic lymphoma kinase-translocation renal cell carcinoma: clinical and pathological analysis / 中华病理学杂志

Objective: To investigate the clinicopathological features, molecular characteristics, differential diagnosis and prognosis of anaplastic lymphoma kinase (ALK)-translocation renal cell carcinoma. Methods: Two cases of ALK-translocation renal cell carcinoma diagnosed from January 2011 to December 2020 were retrospectively analyzed to characterize their morphological features, immunohistochemical expression and prognosis. Multiple molecular studies including fluorescence in situ hybridization (FISH), reverse transcriptase-polymerase chain reaction (RT-PCR), and next-generation sequencing were performed to characterize the genetic alterations. Results: Two patients included one male and one female, with 59 and 57 years old, respectively. Morphologically, case 1 resembled collecting duct carcinoma or renal medullary carcinoma, which demonstrated tubular, microcapsule and reticular structures, with a remarkable myxoid background and lymphocytes infiltration; case 2 resembled Xp11.2 translocation renal cell carcinoma or type 2 papillary renal cell carcinoma, which demonstrated tubular papillary and focal solid structures, with flocculent cytoplasm and many foamy histiocytes, but without myxoid background and lymphocytes infiltration. Immunohistochemistry showed strongly positive expression of ALK. CK7, E-cadherin, vimentin, PAX8 and CD10 showed various degrees of expression, and other antibodies were nonreactive. A variety of molecular assays showed definite ALK gene translocation, with rare VCL-ALK gene fusion (VCL exon and 16-ALK exon 20) in case 1, and EML4-ALK gene fusion (EML4 exon and 2-ALK exon 20) in case 2. Conclusions: ALK-translocation renal cell carcinoma is rare with various morphological features, and is easy to miss and misdiagnose. The characteristic ALK expression and molecular detection of ALK translocation are helpful for diagnosing this type of renal cell carcinoma.

Succinate dehydrogenase-deficient renal cell carcinoma:a clinicopathological, ultrastructural and molecular analysis / 中华病理学杂志

Objective: To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods: A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results: There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions: SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.

Expression of H3.3 G34W mutant-specific antibody in giant cell tumors of bone and its diagnostic value / 中华病理学杂志

To investigate the expression of H3.3 G34W mutant-specific antibody in giant cell tumors of bone (GCTB), and its value in the diagnosis of GCTB. Immunohistochemical (IHC) EnVision method was used to detect the expression of H3.3 G34W mutant-specific antibody and p63 in 83 GCTBs, 18 aneurysmal bone cysts, 23 chondroblastomas and 28 osteosarcomas diagnosed at Nanjing Jinling Hospital from June 2001 to April 2019. Among the 83 cases of GCTB, 69 cases (69/83, 83.1%) expressed H3.3 G34W. H3.3 G34W expression was found exclusively in the mononuclear cell population with strong and diffuse nuclear staining. H3.3 G34W was expressed in 55 of 57 (96.5%) cases of GCTB in long bones, but only 14 of 26 (53.8%) cases of non-long bone GCTB. All recurrent (9/9)/metastatic GCTB (2/2), post-denosumab GCTB (3/3), primary malignant GCTB (3/3) and secondary malignant GCTB (5/5) also expressed H3.3 G34W. H3.3 G34W was negative in all aneurysmal bone cysts and chondroblastomas. H3.3 G34W was positive in 3 of 28(10.7%) cases of osteosarcomas, and giant cell-rich osteosarcoma(GCRO) was the only histological subtype of osteosarcoma that expressed H3.3 G34W. p63 was expressed in 71.1%(59/83) of GCTB, while the positive rates of p63 in aneurysmal bone cysts,chondroblastomas and osteosarcomas were 3/18, 43.5% (10/23) and 21.4% (6/28) respectively. The sensitivity and specificity of H3.3 G34W mutant-specific antibody in the diagnosis of GCTB were 83.1% and 95.7%. H3.3 G34W mutant-specific antibody is a highly sensitive and specific marker for GCTB and helpful for the diagnosis of GCTB and its variants. The limitation of this antibody is that as a mall number of GCTB harbor G34 mutation other than G34W, and thus that cannot be detected. The incidental expression of H3.3 G34W mutant protein in osteosarcoma could be a potential diagnostic dilemma, and the results of H3.3 G34W IHC staining needs careful interpretation.

DNA re-use after immunohistochemical staining of FFPE sections of non-small cell lung cancer / 医学研究生学报

Objective　The purpose of this study was to evaluate the quality of DNA from the formalin-fixed paraffin-embedded (FFPE) specimens of non-small cell lung cancer (NSCLC) after immunohistochemical staining and investigate DNA extraction by immunohistochemical staining of the specimens in small in number or difficult to obtain and the feasibility of related molecular tests.　Methods　We randomly collected 50 FFPE biopsy specimens of NSCLC in our Department of Pathology from June 2017 to December 2017 and sliced each into 12 sections, of which, 6 were directly subjected to DNA extraction (the control group) and the other 6 to immunohistochemical Envision two-step staining for DNA extraction (the experimental group). Then, we detected the mutations of the epidermal growth factor receptor (EGFR), kirsten rat sarcoma viral oncogene (KRAS) and V-raf murine sarcoma viral oncogene homolog B (BRAF) in all the DNAs extracted.　Results　No statistically significant differences were observed between the experimental and control groups in the DNA concentration and purity in the 50 FFPE biopsy specimens of NSCLC (P>0.05). Of the 50 NSCLC FFPE specimens of the experimental group, 20 (40%) showed the mutation of EGFR, 8 (16%) exhibited that of KRAS, and 5 (10%) manifested that of BRAF. In the other 50 specimens of the control group, 33 showed the mutations of EGFR, KRAS and BRAF. A 100% consistency was found in the results of detection between the experimental and control groups (P=0.000, Kappa=1.000).　Conclusion　 High-quality DNA can be extracted after immunohistochemical staining from NSCLC FFPE specimens, especially those small in number or difficult to obtain, and can be used for downstream molecular analysis of target genes, which is a good method for specimen recycling and provides a solution for subsequent molecular test of scarce or difficult-to-obtain clinical samples.

Primary mediastinal germ cell tumors: the clinicopathologic analysis of 56 cases / 临床与实验病理学杂志

Purpose To investigate the clinicopathologic features of primary mediastinal germ cell tumors and to improve the diagnosis and treatment guidance. Methods The clinical features, histologic findings, molecular detection and biological behaviors of 56 PMGCT cases were analyzed retrospectively. Results The age of patients ranged from 9 to 48 years (median age 29.1 years), and mature teratoma(76.8％, 43/56) were the most common type.3 cases of mature teratoma were prepubertal patients.53 cases of postpubertal patients included 40 cases of mature teratoma, 2 cases of nonmature teratoma, 2 cases of yolk sac tumor, 5 cases of seminoma, 4 cases of mixed germ cell tumor. All malignant PMGCTs were male, and mature teratoma was found in the female. Histopathologic morphology and immune phenotype of primary mediastinal germ cell tumors were consistent with those of sexual gland. The isochromosome 12p was detected in various component of malignant GCTs, not in mature teratoma. All patients underwent surgical resection, with additional chemotherapy for malignant germ cell tumor cases. The prognosis of mature teratoma regardless of prepubertal or postpubertal patients was benign, but PMGCTs (except mature teratoma) of postpubertal type were malignant. Conclusion Primary mediastinal germ cell tumors are rare and mature teratoma is most common. The malignant PMGCTs mostly occur in young men. The abnormal 12p detected by FISH is helpful to differential diagnosis and guide the treatment.

Pigmented dermatofibrosarcoma protuberance: a clinicopathologic analysis of 7 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinical pathological features, diagnosis and differential diagnosis of pigmented dermatofibrosarcoma protuberance (PDFSP).</p><p><b>METHODS</b>The clinical history, histopathological features, immunohistochemical characteristics, treatment and prognosis were analyzed in seven cases of PDFSP. Fluorescence in situ hybridization (FISH) was used to detect the expression of COL1A1/PDGFB fusion gene, and related literature was reviewed.</p><p><b>RESULTS</b>The median age of the seven patients (4 females, 3 males) was 47 years with the tumors involving mostly the trunk (four cases). Histologically, PDFSP showed a cellular lesion composed of spindle cells arranged in short fascicles that form a distinct storiform pattern, and the pigmented bipolar or multipolar dendritic cells were present with tentacle like processes emanating from a nucleus containing zone. One case showed fibrosarcomatous change. The pigment was tinctorially similar to melanin. The spindle cells were positive for CD34 and vimentin, but negative for HMB45, Melan A, S-100, desmin, CD68 or α-SMA. HMB45, Melan A, S-100 and vimentin were expressed in the melanin containing cells in 4, 4, 5 and 7 cases, respectively. The labeling index of Ki-67 was 1%-8%. Among the 4 cases successfully examined by FISH, 3 showed t(17;22)(q21;q13) which suggested COL1A1/PDGFB fusion gene. Three patients were treated by wide local excision and four were treated by simple surgical excision. Two patients developed recurrences during the follow-up period of 12 to 123 months. Of those treated by wide local excision, none developed recurrence. No patient died in the follow-up period.</p><p><b>CONCLUSIONS</b>PDFSP is a rare pigmented variant of DFSP and an intermediate grade malignant tumor. The orgin of the tumor cells is still controversial. Surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of PDFSP as there is a risk of misdiagonsing it as either pigmented tumors associated with neurocutaneous syndromes or a highly malignant melanocytic neoplasm.</p>

Clinicopathological features of colorectal neuroendocrine neoplasms and prognostic significance of WHO staging system / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the clinicopathological characteristics of colorectal neuroendocrine neoplasms (NENs) and the prognostic significance of the new WHO classification and staging system about gastroenteropancreatic NENs.</p><p><b>METHODS</b>The clinical and pathological records were reviewed in 73 patients with colorectal NENs (carcinoids). All slides were retrieved and reviewed, immunohistochemical staining (EnVision method) was performed and follow-up information retrieved.</p><p><b>RESULTS</b>Forty-one men and thirty-two women were included with a median age of 53 years (19 - 79 years). The location of the primary tumors in 65 patients was within 10 cm from the anorectal line. In 45 cases, the tumor diameter was ≤ 1 cm (no metastasis occurred); in 11 cases, the tumor diameter was > 1 cm but ≤ 2 cm (two patients had metastatic tumors); in 17 cases, the tumor diameter was > 2 cm (12 patients had metastatic tumors). The metastatic rate was significantly correlated with tumor size (P = 0.000). All tumors were immunoreactivity for synaptophysin and/or chromogranin A. According to the criteria of WHO classification and staging system about gastroenteropancreatic NENs, there were 65 cases of neuroendocrine tumors, including 51 cases of grade 1 (G1), 14 cases of grade 2 (G2), 4 cases of neuroendocrine carcinoma (G3) and 4 cases of mixed adenoneuroendocrine carcinoma. Following-up data showed that of the 34 patients with G1 tumor, there were no tumor-related death, but two patients showed metastases, and the remaining patients were disease free for 6 to 179 months. Of the 12 patients with G2 tumors, five developed metastasis, there were two tumor-related deaths, and the nine surviving patients were alive for 17 to 118 months. Of the four G3 patients, all developed metastasis and there were three tumor-related deaths. Of the four mixed adenoneuroendocrine carcinoma there were two tumor-related deaths. The difference of metastatic rate, tumor-related mortality, and overall survival among different grading groups in this series was statistically significant (P = 0.000).</p><p><b>CONCLUSIONS</b>Colorectal neuroendocrine neoplasm is a group of tumors with distinct prognostic difference, and most of these tumors show an indolent clinical behavior. There is a good correlation between the new WHO classification and staging system of gastroenteropancreatic NENs and their clinical behaviors.</p>

Immunohistochemical study of perivascular epithelioid cell neoplasms / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotype and genetic changes of perivascular epithelioid cell neoplasms (PEComa).</p><p><b>METHODS</b>A total of 25 cases of PEComa located in various anatomic sites were selected for immunohistochemical staining (SP or EnVision method). TFE3 fluorescence in-situ hybridization was also performed to determine the TFE3 gene status.</p><p><b>RESULTS</b>The age of patient ranged from 21 to 61 years (mean = 43 years). The male-to-female ratio was 1: 1.3. Histologically, 22 cases represented conventional angiomyolipomas, composed of a mixture of adipose tissue, spindle element, epithelioid smooth muscle cells and abnormal thick-walled blood vessels in various proportions. Three cases involving lung, soft tissue and broad ligament had subtle but distinctive morphologic features. Nested or sheet-like architecture with epithelioid or spindle cells was observed. Immunohistochemical study showed that HMB 45, melan A, smooth muscle actin and cathepsin K were expressed in 80% (20/25), 88% (22/25), 88% (22/25) and 100% (25/25) of PEComa, respectively. Within positive cases, the average proportion of positive tumor cells was 36%, 41%, 35% and 90% respectively for HMB 45, melan A, smooth muscle actin and cathepsin K. TFE3 was negative in all of the 22 renal and hepatic PEComa studied, while it was positive in the 3 cases of extra-hepatorenal PEComa. None of the 25 cases exhibited evidence of TFE3 gene fusion or amplification.</p><p><b>CONCLUSIONS</b>Extra-hepatorenal PEComa have distinctive morphologic features and are associated with TFE3 overexpression. Cathepsin K immunostaining demonstrates high sensitivity and specificity in PEComa, better than other commonly employed immunomarkers. This marker is thus useful in diagnosis of PEComa and distinction with other neoplasms.</p>

Prognostic significance of a newly proposed grading and scoring system in stage I pulmonary adenocarcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To evaluate the prognostic significance of a new grading and scoring system (based on the new IASLC/ATS/ERS classification) in stage I pulmonary adenocarcinoma, as compared with the WHO grading system.</p><p><b>METHODS</b>The clinicopathologic characteristics of 125 patients with stage I pulmonary adenocarcinoma primarily treated by surgical resection were reviewed retrospectively. All cases were classified according to the new IASLC/ATS/ERS classification and graded into three prognostic groups based on the new classification, the Sica scoring system and the WHO grading system, respectively. The differences in prognosis of the three groups were analyzed.</p><p><b>RESULTS</b>There was a statistically significant correlation between the new grading system and the WHO grading system (P = 0.000). Both of them showed negative correlation with overall survival. The new scoring system however better correlated with disease recurrence and/or metastasis (P = 0.855, P = 0.073 versus P = 0.011). According to univariate Log-rank test, the prognosis correlated with tumor size (P = 0.004), clinical stage (P = 0.000), the WHO grading (P = 0.020), the new grading system (P = 0.000), the new scoring system (P = 0.000), vascular invasion (P = 0.021), and recurrence and/or metastasis (P = 0.000). The Cox regression analysis demonstrated that clinical stage (P = 0.014), the new grading system (P = 0.047), the new scoring system (P = 0.043), and recurrence and/or metastasis (P = 0.018) were significantly independent poor prognostic factors.</p><p><b>CONCLUSIONS</b>The new grading and scoring system shows good correlation with the WHO grading system. Compared with the WHO grading system, the new scoring system based on the new IASLC/ATS/ERS classification provides valuable information in categorizing stage I pulmonary adenocarcinoma cases with different risks of disease recurrence, tumor metastasis and prognosis.</p>

Inhibitive effect of C-21 steroidal glycosides of Cynanchum auriculatum on rat glioma cells in vitro / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To evaluate the inhibitive effect of C-21 steroidal glycosides from the root of Cynanchum auriculatum (CGB) on rat glioma C6 cells.</p><p><b>METHODS</b>C6 cells were treated with CGB for 24, 48,72 h at concentration of 30, 60, 120 mg/L, respectively. MTT assay was used for evaluating cell viability; fluorescence-activated cell sorting analysis after Annexin V/propidium iodide staining or single propidium iodide staining was used to test cell apoptosis and cell cycle.</p><p><b>RESULTS</b>CGB at 30, 60, 120 mg/L concentration-dependently decreased C6 cell viability (P<0.001). CGB at 60 and 120 mg/L induced C6 cell apoptosis and cell cycle arrest. The fraction of G0/G1 cells was increased (P<0.05) and that of S phase cells was decreased (P<0.01).</p><p><b>CONCLUSION</b>CGB can inhibit the growth of rat glioma C6 cells, and induce apoptosis and G0/G1 cell cycle arrest.</p>

Expression and clinical significance of kidney injury molecule-1 in renal epithelial neoplasms / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression and clinical significance of kidney injury molecule-1 (KIM-1) in primary and metastatic renal epithelial neoplasms.</p><p><b>METHODS</b>A total of 136 cases of kidney neoplasms were retrospectively reviewed including 63 primary clear cell renal cell carcinomas (RCCs), 22 papillary RCCs, 13 chromophobe RCCs, 7 oncocytomas, 7 RCCs associated with Xp11.2 translocation/TFE3 gene fusions and 24 metastatic clear cell RCCs. Immunostaining for KIM-1 and kidney-specific-protein (Ksp)-cadherin were performed and the relationship to tumor stage and grade in clear cell RCCs was investigated.</p><p><b>RESULTS</b>Expression of KIM-1 was detected in 77.8% (49/63) of clear cell RCCs, 90.9% (20/22) of papillary RCCs, 1/13 of chromophobe RCCs, 7/7 of RCCs associated with Xp11.2 translocation/TFE3 gene fusions and 87.5%(21/24) of the metastatic RCCs, but not detected in 7 cases of oncocytomas. A diffuse expression of KIM-1 was more frequently observed in Furhman nuclear grade III/IV clear cell RCCs (P = 0.010). Ksp-cadherin expression was mainly observed in chromophobe RCCs and oncocytomas.</p><p><b>CONCLUSIONS</b>KIM-1 is a specific biomarker for injuried kidney proximal tubules and the corresponding neoplasms, and has a high specificity and sensitivity for primary or metastatic clear cell RCCs, papillary RCCs and RCCs associated with Xp11.2 translocation/TFE3 gene fusions. Combination of KIM-1 and Ksp-cadherin immunostaining can lead to a more precise histological classification of primary kidney epithelial neoplasms and improve the diagnostic accuracy of metastatic RCCs.</p>

Clinicopathologic study of von Hippel-Lindau syndrome-related and sporadic hemangioblastomas of central nervous system / 中华病理学杂志

<p><b>OBJECTIVE</b>To study clinicopathologic features, diagnosis, treatment and prognosis of von Hippel-Lindau (VHL) syndrome-related and sporadic hemangioblastomas of the central nervous system (CNS-HB).</p><p><b>METHODS</b>Histopathological, ultrastructural, immunohistochemical (EnVision method) and clinical features of 21 VHL syndrome and 63 sporadic CNS-HB cases were studied with correlation of the available follow-up information.</p><p><b>RESULTS</b>Twenty-one VHL patients accompanied with a total of 87 CNS-HBs, including one patient of developing 12 HBs within 13 years. There were 10 patients presenting other lesions related to VHL, including 6 retinal HBs, 4 pancreatic tumors (endocrine tumor and microcystic cystadenoma), 1 clear renal cell carcinoma, 4 renal cysts and 1 endolymphatic sac tumor. One patient developed 5 different tumors related to VHL within a period of 4 years. In the 63 cases of sporadic CNS-HB (34 male and 29 female), the mean age was 43.0 years. Among the 18 VHL syndrome patients with available follow-up information, 14 were still alive and within them, 4 became disabled and 11 had developed new lesions. The other 4 patients died. Among the 42 patients of sporadic HB with follow-up information, 39 were alive including 3 disabled cases, and the other 3 died. Histologically, the tumors showed large and vacuolated stromal cells. Some tumors showed atypical nuclei. Involvement of the brain tissue was seen in 32 cases, among which, 21 patients with available follow-up information were learnt to be alive. Tumor cells of HB stained positive for vimentin, EGFR, Inhibin alpha and D2-40, but negative for CD34 and CD68. In 3 cases of HB, some stromal cells were positive for GFAP. All cases showed a low expression for Ki-67, except 2 cases with 2% and 1 case with 5% Ki-67 indices.</p><p><b>CONCLUSIONS</b>VHL syndrome is a multisystem disorder with a poor prognosis and a high rate of missed diagnosis. The syndrome is characterized by development of various benign and malignant tumors. The most common tumor is CNS-HB, which occurs predominantly in the cerebellum. Patients with VHL syndrome tend to present at a younger age than patients with sporadic CNS-HBs, and VHL related HB occurs more predominantly in the brain stem and spinal cord. Prognosis of CNS-HB patients is not correlated with the nuclear atypicality, expression for Ki-67 and involvement of the brain tissue. Because new lesions may develop during the patient's lifetime. So that, regular clinical inspection is recommended in order to check up the development of any new lesions.</p>

Clinicopathologic and molecular genetic study of renal cell carcinoma occurring in teenagers / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate clinicopathological features, molecular genetic characteristics, differential diagnoses and prognosis of renal cell carcinoma in teenagers.</p><p><b>METHODS</b>Microscopic and immunohistochemical features of 46 cases of renal cell carcinomas in teenagers were reviewed along with the clinical follow-up data. Loss of heterozygosity (LOH), analysis of von Hippel-Lindau (VHL) gene and screening for VHL gene mutations were performed in all of the tumors.</p><p><b>RESULTS</b>There were 19 Xp11.2 translocations/TFE3 gene fusions renal clear cell carcinomas (Xp11 RCCs), 9 chromophobe renal cell carcinomas (CCRCCs), 17 papillary renal cell carcinomas (PRCCs), and 1 unclassified renal cell carcinoma (RCC). All of the 19 Xp11.2 translocation RCCs showed a moderate to strong immunoreactivity for TFE, however, no TFEB expression was obtained. There were 4 histological patterns in the Xp11 RCC cases including: 8 tumors possessing a nested to papillary architecture resembling to the t(X;17) ASPL-TFE3 phenotype; 6 tumors possessing a morphologic feature like the t(X;1) PRCC-TFE3 phenotype; 4 cases morphologically resembling to clear cell RCC; and 1 Xp11 RCC case, with a special morphologic feature not searched yet in the literature, including a ground glass appearance of the nuclei accompanying occasionally with grooves on the nuclear surface; nucleoli inconspicuous with accumulation of abundant mucin-like substance in the stroma. VHL gene analysis revealed deletions at 3p25-26 in one clear cell RCC and one papillary type 2 RCC. The papillary type 2 RCC had also a family history of VHL disease, with a germline G→C mutation at a splicing site of position 553+5. There were no VHL mutations detected in the remaining 45 RCCs. Statistical analysis of tumor stage and outcome revealed that TFE+ RCCs of teen-agers were more frequently associated with a higher pT3/pT4 stage and a poorer outcome than that of the TFE-RCCs (P < 0.05).</p><p><b>CONCLUSIONS</b>RCCs of the teenagers have a different morphologic spectrum and genetic background from the RCCs seen in adults. Among RCCs of the teen-agers, Xp11.2 translocation tumors are the most common RCCs and have a poorer prognosis than that of the TFE-RCCs.</p>

Clinicopathologic study of pilocytic astrocytoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To study clinicopathologic features, treatment and prognosis of pilocytic astrocytoma (PA).</p><p><b>METHODS</b>Histopathological, ultrastructural, immunohistochemical (EnVision method) and clinical features of 68 cases of PA were studied by microscopic investigation with correlation of clinical follow-up information when available.</p><p><b>RESULTS</b>Thirty-five male patients and 33 female patients were studied. The patient's age ranged from 3 to 66 years (mean = 20.1 years). The mean time from symptom onset to surgery was 371 days (range, 3 days to 14 years). Cystic degeneration was noted in 41 cases (60.3%), and enhancement of the tumor was noted in 43 cases (87.8%). On postcontrast imaging examination there were 33 cases involving the cerebellum (48.5%). Total tumor excision was performed in 35 patients, subtotal tumor excision was performed in 31 patients, and the procedures of other 2 patients were not clear. Among 51 patients with follow-up information, 44 were alive, 7 had recurrent tumor, and 7 died. The post-operative survival ranged from 2 months to 124 months (mean survival = 48.1 months). Five years and ten years survival rates were 89%, respectively. Tumors with classic histopathology demonstrated biphasic pattern of growth, consisting of compact elongated bipolar astrocytes associated with rosenthal fibers, and less cellular areas of multipolar cells with granular bodies and microcyst. Some cases showed atypia of nuclei, and occasional mitoses. Involvement of subarachnoid space was seen in 17 cases. One case had anaplastic features. All cases showed diffuse positive staining for GFAP and low expression for Ki-67, except 1 anaplastic tumor with 10% Ki-67 indices. Tumors with subarachnoid space involvement showed positive reticular fiber staining and negative EMA staining.</p><p><b>CONCLUSIONS</b>PA is a benign, WHO grade I tumor with favorable prognosis, and does not require radiotherapy after total resection. The tumor can be mistaken as higher-grade astrocytoma when involving the subarachnoid space, and with cytological atypia, leading to unnecessary radiotherapy after surgery. Recurrence rate is increased when only partial resection is achieved. The outcome for patients with brainstem tumor or anaplastic PA is poor.</p>

Expression of Ksp-cadherin in renal epithelial neoplasm and its clinicopathologic significance / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression of a novel marker, kidney-specific-protein (Ksp)-cadherin, in renal epithelial neoplasms and its clinicopathologic significance.</p><p><b>METHODS</b>Immunohistochemical study (using EnVision method) for Ksp-cadherin, CD10, vimentin, epithelial membrane antigen and CK7 was carried out in normal human kidney samples, as well as in 166 cases of primary renal neoplasms (including 120 cases of clear cell renal cell carcinoma (RCC), 20 cases of papillary RCC (type I papillary RCC 15 cases and type II papillary RCC 5 cases), 18 cases of chromophobe RCC and 8 cases of oncocytoma).</p><p><b>RESULTS</b>Ksp-cadherin was expressed in distal convoluted tubules of normal kidney in a membranous pattern. It was also detected in 23% (27/120) of clear cell RCC, 20% (4/20) of papillary RCC, 100% (18/18) of chromophobe RCC and 75% (6/8) of oncocytoma. High expression of CD10 and vimentin was noted in clear cell RCC and papillary RCC. CD10 was also expressed in chromophobe RCC in cytoplasmic pattern, compared with membranous staining in the other tumors. CK7 expression was mainly seen in chromophobe RCC and papillary RCC, while epithelial membrane antigen was expressed in all variants of RCC. On the other hand, the expression of Ksp-cadherin in clear cell RCC correlated with tumor stage and grade.</p><p><b>CONCLUSIONS</b>Ksp-cadherin is expressed in normal distal convoluted tubules and the related neoplasms. It carries relatively high specificity and sensitivity in diagnosis of chromophobe RCC and oncocytoma. The expression of Ksp-cadherin also correlates with biologic behavior of clear cell RCC.</p>