Pituicytoma: a clinicopathological analysis of twenty-one cases / 中华病理学杂志

Objective: To investigate the clinicopathological features and treatment strategies of pituicytoma. Methods: Twenty-one cases of pituicytoma were collected at the First Affiliated Hospital of Nanjing Medical University and Jinling Hospital, Nanjing, China from 2009 to 2020. The clinical data of 21 pituicytoma patients was retrospectively analyzed, and the relevant literature was reviewed. Results: Twenty-one patients aged 4 to 68 years, including 8 males and 13 females. All patients underwent surgical treatment. Histologically, the tumor was consisted almost entirely of elongate, bipolar spindle cells arranged in a fascicular or storiform pattern. Mitotic figures were rare. Immunohistochemically, tumor cells were diffusely positive for S-100 protein (21/21), vimentin (15/15) and TTF1 (14/14), while they were weakly or focally positive for GFAP (13/16) and EMA (6/12). CKpan was negative in all cases and Ki-67 proliferation index was low (<5%). Among the 18 patients with follow-up, all survived and 2 relapsed after surgery. Conclusions: Pituicytoma is a rare low-grade glioma of the sellar area. It is easily confused with other sellar tumors. Preoperative diagnosis is difficult. It needs to be confirmed by histopathology and immunohistochemistry. Microsurgery is the main treatment method at present.

Expression and diagnostic value of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma / 中华病理学杂志

Objective: To investigate the immunohistochemical expression of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma (MC), and to explore the differential diagnostic value of NKX3.1 and NKX2.2 in MC and other types of small round cell malignant tumors. Methods: A total of 12 cases of MC and 97 other small round cell malignant tumors diagnosed in Jinling Hospital, Nanjing University School of Medicine from 2001 to 2020 were collected for NKX3.1 and NKX2.2 immunohistochemical detection. Among them, two kinds of NKX3.1 antibodies [rabbit polyclonal antibody and rabbit monoclonal antibody (EP356)] were used for detection in 12 cases of MC, and one NKX3.1 antibody (rabbit polyclonal antibody) was detected in 97 cases of other small round cell malignant tumors, and the relevant literature was reviewed. Results: The 12 MC patients included 7 females and 5 males, with a mean age of 33 years (14-54 years). Nine cases were from bone and three from soft tissue. Among the 12 MC patients, 8 patients had postoperative recurrence or metastasis, and 3 of them died of tumor recurrence or metastasis. Histologically, 12 cases of MC showed typical bidirectional differentiation.The positive rate of both NKX3.1 antibodies in MC was 12/12, NKX3.1 was focal weakly positive in only one of 12 chondrosarcomas (grade 3), 5 alveolar rhabdomyosarcomas, 5 embryonal rhabdomyosarcomas, and 5 solitary fibrous tumors, respectively. The remaining 70 cases of other small round cell malignant tumors were negative. The positive rates of NKX2.2 in MC, Ewing sarcoma and olfactory neuroblastoma were 12/12, 15/15 and 4/5, respectively. In 12 cases of chondrosarcoma (grade 3), 5 cases of poorly differentiated synovial sarcoma, 5 cases of alveolar rhabdomyosarcoma, and 5 cases of solitary fibrous tumor, NKX2.2 was focally and weakly positive in only one case, respectively, and all the remaining 50 cases of other small round cell malignant tumors were negative. Conclusions: The expression of NKX3.1 and NKX2.2 proteins are significant indicators in the diagnosis of MC, and the combined detection of NKX3.1 and NKX2.2 can help distinguish MC from most other small round cell malignant tumors.

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.

Papillary renal neoplasm with reverse polarity: a clinicopathological analysis / 中华病理学杂志

Objective: To study the clinical pathological characteristics, immunophenotype, molecular changes and prognosis of the papillary renal neoplasm with reverse polarity (PRNRP). Methods: Nine cases of PRNRP, diagnosed from 2013 to 2019, were retrieved from the Department of Pathology of Nanjing Jinling Hospital, Nanjing University School of Medicine. Histomorphology, immunophenotype and molecular genetics were analyzed with review of the literatures. Results: There were five male and four female patients, aged from 49 to 70 years, with an average age of 60.1 years. During a mean follow-up of 29 months, one patient died for other cause, and the others survived without disease. Microscopically, the tumor cells arranged in papillary structure with a fibrovascular core, the surface of which was covered with a single layer of cuboidal or columnar cells. The most prominent feature was that the tumor nuclei located at the top of the cytoplasm far from the basement membrane, and they were monotonous in size and arranged neatly with no or few nucleoli. Immunohistochemically, all nine cases of PRNRP showed diffuse positive expression of CK7 and E-cadherin, various degrees of P504s expression, and no expression of CD10 and CD117, with a Ki-67 index of 1%-3%. Unlike other papillary renal cell carcinoma, the nine cases of PRNRP all showed characteristic positive expression of GATA3. The fluorescence in situ hybridization assay showed that the majority of PRNRPs (8/9) did not have triploids on chromosomes 7 and 17. The sequencing of the KRAS gene confirmed the presence of a nonsense KRAS mutation in 8 of the 9 cases. Conclusions: PRNRP is a subtype of papillary renal cell carcinoma with characteristic morphological, immunophenotypic and molecular features, and indolent behaviors. More data are needed to define PRNRP as "carcinoma", and a definitive diagnosis of PRNRP is of great significance for proper treatment choice and accurate prognostication.

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

Objective@#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.@*Methods@#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.@*Results@#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%.@*Conclusions@#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.

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.

Eosinophilic solid and cystic renal cell carcinoma: clinicopathological analysis and molecular characterization / 中华病理学杂志

Objective@#To study the clinicopathological features, immunohistochemical phenotype, molecular changes, differential diagnosis and prognosis of eosinophilic solid and cystic renal cell carcinoma (ESC RCC).@*Methods@#A total of 15 cases were selected from 2005 to 2019 at Nanjing Jinling Hospital,Nanjing University School of Medicine for clinicopathological and immunohistochemical analysis, 10 of which were subject to cancer-associated mutation analysis using targeted next-generation sequencing (NGS) panel. A literature review was also performed.@*Results@#The patients′ ages ranged from 15 to 68 years (mean, 33 years). The male-to-female ratio was 1.1∶1.0. During a mean follow-up of 22 months, none of the patients developed tumor recurrence, progression or metastasis. Histologically, the tumors typically demonstrated solid and cystic architectures and the neoplastic cells contained voluminous eosinophilic cytoplasm with prominent granular cytoplasmic stippling. Immunohistochemically, tumor cells in all cases were immunoreactive for CK20. Signal pathway related protein mTOR and S6 were positive in 14/15 and 6/15 cases, respectively. Cathepsin K, Melan A and HMB45 were at least focally positive in 12/15, 6/15 and 2/15 cases, respectively. CK7 and CD10 showed focal immunostain positivity in some cases, while TFE3, TFEB, CA9 and CD117 were negative in all cases. NGS demonstrated TSC1/TSC2 mutations in all tested cases (10/10).@*Conclusions@#ESC RCC is a rare tumor that tends to occur in young patients with an indolent behavior. Diagnosis can be established by its distinct clinical and histopathologic findings, immunohistochemical phenotype and molecular genetics. The tumor may be considered as a new subtype of RCC.

Xp11 neoplasma with melanocytic differentiation: a clinicopathological analysis / 中华病理学杂志

Objective@#To investigate the clinical, histologic and immunophenotypic features, genetic alterations and prognosis of the rare Xp11 neoplasm with melanocytic differentiation.@*Methods@#Twenty-one cases were selected from the Department of Pathology, Jingling Hospital, Nanjing University School of Medicine from May 2008 to May 2018. The clinicopathologic, immunohistochemical, molecular analysis and follow-up details were collected.@*Results@#There were 7 males and 14 females, with their ages ranging from 4 to 57 years (mean 32.8 years). The tumors were located in kidney (11 cases), pelvis (three cases), and in pancreas, retroperitoneum, adrenal gland, small intestine, prostate, cervix and appendix (one case each). Microscopically, most tumors shared similar morphology such as purely nested or sheet-like architectures separated by a delicate vascular network, purely epithelioid cells with clear to granular eosinophilic cytoplasm, lacks of papillary structures, spindle cell or fat components, uniform round to oval nuclei with small visible nucleoli, and in most of them (16/21) melanin pigment. Immunohistochemically, all cases showed moderately (2+) or strongly (3+) positive staining for TFE3 and Cathepsin K. HMB45 and Melan A were focally expressed in three of 21 cases, while the remaining cases showed typically moderate(2+) or strong (3+) expression. None of the cases were immunoreactive for SMA, desmin, CKpan, S-100 and PAX8. All cases showed TFE3 rearrangement using fluorescence in-situ hybridization (FISH). Fusion FISH assays detected SFPQ-TFE3 gene fusion in 16 cases, NONO-TFE3 gene fusion in two, ASPL-TFE3 and MED15-TFE3 gene fusions in one case each. Polymerase chain reaction and direct sequencing detected SFPQ-TFE3 gene fusion in nine cases, NONO-TFE3 and MED15-TFE3 gene fusions in one case each. Clinical follow-up was available for 15 patients for 12 to 74 months. Six patients died of the disease; and three had recurrences and/or metastases. Six patients were alive with no evidence of disease after initial resection.@*Conclusions@#Xp11 neoplasm with melanocytic differentiation has unique morphologic, immunophenotypic and genetic characteristics. The tumor is aggressive, and should be differentiated from Xp11 translocation RCC and perivascular epithelioid cell tumor.

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 testicular diffuse large B-cell lymphoma: A clinicopathological analysis / 中华男科学杂志

Objective@#To investigate the clinicopathological features, immunophenotype and treatment of primary testicular diffuse large B-cell lymphoma (DLBCL).@*METHODS@#We retrospectively analyzed the pathomorphological characteristics and immunohistochemical markers of 23 cases of primary testicular DLBCL as well as their clinicopathological features with a review of the relevant literature. The patients were aged 48－76 (mean 61.4) years, 82.6% over 50 years, and all clinically presented with painless progressive unilateral testicular swelling, 9 cases in the left and the other 14 in the right testis.@*RESULTS@#Histologically, the lymphomas were composed of large atypical cells with prominent karyokinesis and diffusely infiltrated the testicular parenchyma. The neoplastic cells were positive for B-cell markers. Five of the patients were followed up for 2 to 32 months, of whom 4 survived and 1 died at 9 months.@*CONCLUSIONS@#Primary testicular DLBCL is a rare tumor with an invasive biological behavior, mostly found in elderly males and easily misdiagnosed or missed in diagnosis. Histopathology plays a key role and immunohistochemical markers are of high value in the definite diagnosis and differential diagnosis of the tumor.

Clinicopathologic and molecular features of myoepithelial tumors of salivary glands / 中华病理学杂志

Objective@#To investigate the clinicopathological, and molecular characteristics of myoepithelial tumors (MTs) of salivary glands.@*Methods@#A total of 37 MTs cases including 13 malignant epithelial tumors (MMTs) and 24 benign epithelial tumors (BMTs) of salivary glands were identified from the archives of the Department of Pathology, General Hospital of Eastern Theater Command, dating from 2006 to 2016. Clinical features, histological patterns, immunohistochemical characteristics and status of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) analysis were reviewed in all cases.@*Results@#Clinically, 37 MTs cases mainly occurred in the parotid glands, when most of the patients presented with painless masses. Of the 13 MMTs cases, male to female ratio was 7∶6, and the median age was 62 years old. Of the 24 BMTs cases, male to female ratio was 5∶7, and the median age was 54 years old. Immunohistochemically, 37 MTs cases were positive for CKpan, and at least one myoepithelial marker. Twenty six of 37 MTs cases were analyzable for the EWSR1 gene break by FISH. Based on the previous evaluation criterion, the EWSR1 translocation was detected in 4 cases of 11 MMTs, and 4 cases of 15 BMTs. According to the main histological composition of tumor cells, 4 EWSR1-positive MMTs covered 2 clear-cell cases and 2 epithelioid-cell cases, when 4 EWSR1-positive BMTs covered 2 clear-cell cases, 1 plasmacytoid-cell case, and 1 spindle-cell case.@*Conclusions@#Males and females are affected equally. MTs express immunoreactivity for CKpan, and at least one myoepithelial marker. The EWSR1 rearrangement is present in a subset of MTs, with variable morphological characteristics, and has no statistical significance on clinical behavior.

Lung non-terminal respiratory unit type adenocarcinoma: a clinicopathologic study / 中华病理学杂志

Objective@#To evaluate the clinicopathologic characteristics of lung non-terminal respiratory unit (non-TRU) type adenocarcinoma.@*Methods@#Seventy-two cases of lung non-TRU type adenocarcinoma that underwent complete resection and diagnosed at Departments of Pathology, Affiliated Suzhou Hospital of Nanjing Medical University and Nanjing General Hospital of the PLA from January 2005 to December 2016 were retrospectively studied. The histomorphological changes and precursor lesions were observed under microscope. The expression of lineage-specific markers and tumor stem cell markers was detected by immunohistochemistry (IHC). The major driver mutations of lung adenocarcinoma were tested by ARMS and directive gene sequencing.@*Results@#Non-TRU type adenocarcinomas were more commonly found in male (65.3%, 47/72), former or current smokers (68.1%, 49/72), the elder (mean 61 years old), central adenocarcinoma (75.0%, 54/72), tumors with necrosis (61.1%, 44/72) and higher grade (73.6%, 53/72). Histologically, non-TRU type adenocarcinoma displayed complex histomorphology and was often composed of large irregular gland-like and acinar pattern accumulating extracellular mucin, necrotic tumor cell debris and neutrophils, or invasive adenocarcinoma with mucin production. The tumor cells were composed of bronchial surface epithelial cells, mucinous column cells, polygonal cells and goblet cells. Eighteen (25.0%), 23 (31.9%) and 28 (38.9%) cases exhibited ciliated columnar cell metaplasia (CCCM), mucous columnar cell change (MCCC) and bronchiolar columnar cell dysplasia (BCCD) (precursor lesion of lung adenocarcinoma). IHC showed the expression of CK7 (100.0%, 72/72), TTF1 (12.5%, 9/72), Napsin A (5.6%, 4/72), MUC5AC (81.9%, 59/72), MUC5B (87.5%, 63/72), p53 (66.7%, 48/72), CK5/6 (12.5%, 9/72), p63 (18.1%, 13/72), CK20 (19.4%, 14/72) and CDX2 (16.7%, 12/72) in the tumor cells. The expression of tumor stem cell markers was detected in 43.1% cases (31/72) for CD44, 31.9% (23/72) for CD133, 58.3% (42/72) for β-catenin, 36.1% (26/72) for ALDH1, 12.5% (9/72) for GATA6, 20.8% (15/72) for SOX2 and 29.2% (21/72) for OCT4. The driver mutations were 26.4% (19/72) for KRAS, 2.8% (2/72) for EGFR and 1.4% (1/72) for EML4-ALK, and none for BRAF and ROS1.@*Conclusion@#Non-TRU type adenocarcinoma is an uncommon subtype of lung adenocarcinoma with distinct clinicopathologic characteristics, histologic appearances, immunophenotype and molecular genetic alterations.

Clinicopatholigic features of renal cell carcinoma associated with chromosome X inversion harboring gene fusions involving TFE3 / 中华病理学杂志

Objective@#To study the clinicopathologic features, immunophenotype, characteristic FISH pattern and prognosis of renal cell carcinoma (RCC) associated with chromosome X inversion harboring gene fusions involving TFE3.@*Methods@#Ten cases of NONO-TFE3 RCC and four cases of RBM10-TFE3 RCC were investigated at Nanjing Jinling Hospital from 2009 to 2016 by clinicopathological findings, immunohistochemistry, and genetic analysis.@*Results@#Morphologically, the distinct pattern of secretory endometrioid subnuclear vacuolization was overlapped with clear cell papillary RCC, and often accompanied by sheets of epithelial cells in NONO-TFE3 RCC. Most cases of RBM10-TFE3 RCC presented with the biphasic feature that acinar, tubular and papillary patterns of epithelioid cells combined with sheets of small cells with "pseudorosette-like" architectures. In addition, cytoplasmic vacuolization, nuclear groove, and psammoma bodies were also observed. Immunohistochemically, all NONO-TFE3 RCC cases were immunoreactive for TFE3, CD10, RCC markers, and PAX8, and negative for CK7, Cathepsin K, Melan A, HMB45, Ksp-cadherin, vimentin, and CD117. All 4 cases of RBM10-TFE3 RCC showed moderate to strong immunoreactivity for TFE3, Cathepsin K, CD10, Ksp-cadherin, E-cadherin, P504s, RCC marker, PAX8, and vimentin but negative for TFEB, HMB45 and CK7. CKpan and Melan A were at least focally expressed. The antibody to Ki-67 showed labeling of 3%-8% (mean 5%). There were some expression discrepancies of immunochemistry between different histological patterns. PAX8, CKpan, P504s, and Ksp-cadherin were expressed in epithelioid areas but not in small-cell areas. Ki-67 labeling index of epithelioid areas was higher than that in small-cell areas. In molecular analysis, NONO-TFE3 fusion transcripts were identified in 6 patients. The fusion points were between exon 7 of NONO and exon 6 of TFE3 in 5 patients and between exon 9 of NONO and exon 5 of TFE3 in one patient. All 4 cases of RBM10-TFE3 RCC demonstrated to have RBM10-TFE3 fusion transcripts and the fusion points were between exon 5 of TFE3 and exon 17 of RBM10. Using TFE3 break-apart FISH assay, all 10 cases of NONO-TFE3 RCC showed characteristic patterns of equivocal split signals with a distance of nearly 2 signal diameters. All 4 cases of RBM10-TFE3 RCC showed colocalized or subtle split signals with a distance of <1 signal diameter, which was considered as negative results. Long-term follow-up was available for 7 patients of NONO-TFE3 RCC and 4 patients of RBM10-TFE3 RCC. All patients were alive with no evidence of disease.@*Conclusions@#Two rare genotypes, NONO-TFE3 RCC and RBM10-TFE3 RCC, are reported in this study. Both of these two tumors show specific morphology and good prognosis, along with the positive TFE3 staining and the equivocal or false-negative TFE3 FISH results, which could be missed. PCR detection or next-generation sequencing can determine the genotype.

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.

Clinicopathologic features of mammary analogue secretory carcinoma of salivary glands / 中华病理学杂志

Objective@#To investigate the clinicopathological features of mammary analogue secretory carcinoma (MASC) of salivary glands, and its diagnosis, differential diagnosis, immunohistochemistry and molecular pathology.@*Methods@#Seventeen cases of MASC were enrolled, with 9 cases of salivary acinar cell carcinoma and 18 cases of adenoid cystic carcinoma as control groups from Nanjing General Hospital from 1997 to 2014 were included in this retrospective study, combined with immunohistochemistry and molecular detection of ETV6-NTRK3 gene fusion. All cases were histologically reviewed with immunohistochemical staining (EnVision) for S-100 protein, SOX10, GATA3, CD117 expression in each group. Fluorescence in situ hybridization (FISH) was used to detect the ETV6-NTRK3 gene fusion.@*Results@#The age of MASC patients ranged from 27 to 74 years with mean age of 47 and ratio of male and female was 4∶3. All cases showed infiltrative growth and diverse cytology and histology, including lobular (8 cases), cystic papillary (3 cases), cribriform mixed with papillary and glandular structures (6 cases) at various proportions. Some tumors of MASC also exhibited solid growth areas with occasional microcystic honeycombed pattern composed of small cysts merged into larger cysts resembling thyroid follicles. S-100 protein and SOX10 were strongly positive in all MASC cases (17/17). In addition, there was insignificant positivity for GATA3 (3/17) and CD117 (4/17). ETV6 gene fusion detection was informative in 12 MASC cases by FISH with 10 positive cases and 2 negative cases.@*Conclusions@#Combined immunohistochemical positivity of S-100 protein, CD117 and SOX10 are useful in the diagnosis and differential diagnosis of MASC. FISH detection of ETV6-NTRK3 fusion offers an additional molecular diagnostic marker for the diagnosis.

Expression and significance of STAT6 in solitary fibrous tumor / 中华病理学杂志

Objective@#To study the clinicopathologic features, the differential diagnosis and the expression of STAT6 in solitary fibrous tumor (SFT).@*Methods@#Eighty cases of SFT were evaluated. The expression of STAT6, CD34, CD99 and bcl-2 protein was studied in these cases and in other groups of soft tissue tumors by immunohistochemical EnVision method. The results were analyzed and relevant literature were reviewed.@*Results@#The expression rate of STAT6 in SFT was 97.5% (78/80) and that in other soft tissue tumors was 3.3% (3/90). The difference was significant (P<0.05). The expression rates of CD34, CD99 and bcl-2 were 88.8% (71/80), 76.3% (61/80) and 75.0% (60/80) in SFT, respectively, which were significantly different from STAT6 expression rate (P<0.05).@*Conclusions@#The expression of STAT6 in SFT has high sensitivity (97.5%) and specificity (96.7%). The expression of STAT6 in SFT is higher than that of CD34, CD99 and bcl-2. STAT6 may be a useful marker for clinical diagnosis of SFT.

Molecular features of metanephric adenoma and their values in differential diagnosis / 中华病理学杂志

Objective@#To study the molecular features of metanephric adenoma (MA) and discuss their values in differential diagnosis.@*Methods@#BRAF V600E immunohistochemistry (IHC) using the mutation-specific VE1 monoclonal antibody and Sanger sequencing of BRAF mutations were performed on 21 MAs, 16 epithelial-predominant Wilms tumors (e-WT) and 20 the solid variant of papillary renal cell carcinomas (s-PRCC) respectively. p16 protein was detected by IHC also. Fluorescence in situ hybridization (FISH) analyses using centromeric probes for chromosome 7 and 17 were performed on the three renal tumors in parallel.@*Results@#Fourteen (14/21, 66.7%) of 21 MA cases demonstrated diffuse, moderate to strong cytoplasmic BRAF V600E IHC staining and the BRAF V600E protein expression was detected in 2 (2/16) of 16 e-WT cases for the first time, whereas all s-PRCCs were negative (P<0.05). All cases (including 14 MAs and 2 e-WTs) with diffuse, moderate to strong cytoplasmic BRAF V600E IHC staining were confirmed to harbor BRAF V600E missense mutations using Sanger sequencing, and no BRAF mutations were detected in cases with negative BRAF V600E protein expression. One case (1/21, 4.8%) showed trisomy of chromosome 7 alone, and another one (1/21, 4.8%) showed trisomy of chromosome 17 alone in 21 MAs. Two cases (2/16) of 16 e-WTs showed trisomy of chromosome 17 alone. In 20 s-PRCCs, trisomy of chromosomes 7 alone was reported in 2 cases (2/20), trisomy of chromosome 17 alone in 3 cases (3/20) and trisomy of chromosome 7 and 17 in 14 cases (14/20). The total positive rates of trisomy of chromosome 7 and/or 17 in MAs, e-WTs and s-PRCCs were 9.6% (2/21), 2/16 and 95.0% (19/20). p16 protein was positive in 81.0% (17/21) MAs, whereas the positive rates in e-WTs and s-PRCCs were 2/16 and 5.0% (1/20).@*Conclusions@#Most MAs harbor BRAF V600E mutations, and MAs lack the gains of chromosome 7 and 17 that are characteristic of papillary renal cell carcinoma. These molecular features can be used to distinguish MA from its mimics. BRAF V600E IHC using the mutation-specific VE1 monoclonal antibody provides an effective method in BRAF V600E mutations detection of renal tumors. p16 is overexpressed in MA, and the finding suggests that the low proliferative rate of the tumor might be attributed to BRAF V600E-induced senescence mediated by p16.

Diagnostic value of immunohistochemistry and FISH for chromosome 12p in type Ⅱ testicular germ cell tumors / 中华男科学杂志

<p><b>Objective</b>To study the pathological morphology, immunohistochemical characteristics, and molecular changes of type Ⅱ testicular germ cell tumors (TGCT) and investigate the possible value of immunohistochemistry and fluorescence in situ hybridization (FISH) in the diagnosis of TGCT.</p><p><b>METHODS</b>We collected for this study 97 cases of TGCT, including 75 cases of seminoma, 17 cases of embryonal carcinoma, 11 cases of yolk sac tumor, 16 cases of mature teratoma, 3 cases of immature teratoma, and 1 case of epidermoid cyst, in which normal testicular tissue was found in 20 and non-TGCT in 6. We detected the expressions of different antibodies in various subtypes of TGCT by immunohistochemistry and determined the rate of chromosome 12p abnormality using FISH.</p><p><b>RESULTS</b>The immunophenotypes varied with different subtypes of TGCT. SALL4 and PLAP exhibited high sensitivity in all histological subtypes. CD117 and OCT4 showed strongly positive expressions in invasive seminoma and germ cell neoplasia in situ (GCNIS) but not in normal seminiferous tubules. GPC3 was significantly expressed in the yolk sac tumor, superior to GATA3 and AFP in both range and intensity. CKpan, OCT4, and CD30 were extensively expressed in embryonal carcinoma, while HCG expressed in choriocarcinoma. The positivity rate of isochromosome 12p and 12p amplification in TGCT was 96.7% (29/30).</p><p><b>CONCLUSIONS</b>The majority of TGCT can be diagnosed by histological observation, but immunohistochemical staining is crucial for more accurate subtypes and valuable for selection of individualized treatment options and evaluation of prognosis. Chromosome 12p abnormality is a specific molecular alteration in type Ⅱ TGCT, which is useful for ruling out other lesions.</p>

Alveolar soft part sarcoma: a clinicopathologic analysis of 48 cases / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features and differential diagnosis of alveolar soft part sarcoma (ASPS).</p><p><b>METHODS</b>The clinical data and pathologic features of 48 cases of ASPS were evaluated. Immunohistochemical study, PAS staining and fluorescence in-situ hybridization (FISH) were carried out in selected examples. Relevant literature was reviewed.</p><p><b>RESULTS</b>Amongst the 48 cases studied, there were 17 males and 31 females, with male-to-female ratio of 1.0∶1.8. The age of patients ranged from 2 to 60 years (median=26 years). The tumor was most commonly located in deep soft tissue, especially that of lower extremities. Histologically, the tumor cells were arranged in alveolar or solid patterns and separated by sinusoidal vessels. They were large and contained abundant eosinophilic granules or crystals in cytoplasm. The nuclei were round to polygonal and vesicular, often with prominent nucleoli. Intravascular tumor extension was common. Some cases showed necrosis, hemorrhage and cystic changes. Immunohistochemical study showed that the tumor cells were positive for TFE3 (100%, 33/33). FISH assay was carried out in 4 cases and all of them had TFE3-ASPL gene fusion.</p><p><b>CONCLUSIONS</b>ASPS is a rare malignant neoplasm, often occurs in young patients. TFE3 is a useful immunohistochemical marker for diagnosis. The diagnosis is further confirmed by other markers.</p>