Browsing by Author "Williamson, Sean R."

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    Diagnostic Criteria for Oncocytic Renal Neoplasms: A Survey of Urologic Pathologists
    (Elsevier, 2017-05) Williamson, Sean R.; Gadde, Ramya; Trpkov, Kiril; Hirsch, Michelle S.; Srigley, John R.; Reuter, Victor E.; Cheng, Liang; Kunju, L. Priya; Barod, Ravi; Rogers, Craig G.; Delahunt, Brett; Hes, Ondrej; Eble, John N.; Zhou, Ming; McKenney, Jesse K.; Martignoni, Guido; Fleming, Stewart; Grignon, David J.; Moch, Holger; Gupta, Nilesh S.; Department of Pathology and Laboratory Medicine, IU School of Medicine
    Renal oncocytoma and chromophobe renal cell carcinoma have been long recognized as distinct tumors; however, it remains unknown if uniform diagnostic criteria are used to distinguish these tumor types in practice. A survey was distributed to urologic pathologists regarding oncocytic tumors. Responses were received from 17 of 26 invitees. Histologically, more than 1 mitotic figure was regarded as most worrisome (n = 10) or incompatible (n = 6) with oncocytoma diagnosis. Interpretation of focal nuclear wrinkling, focal perinuclear clearing, and multinucleation depended on extent and did not necessarily exclude oncocytoma if minor. Staining techniques most commonly used included the following: cytokeratin 7 (94%), KIT (71%), vimentin (65%), colloidal iron (59%), CD10 (53%), and AMACR (41%). Rare cytokeratin 7–positive cells (≤5%) were regarded as most supportive of oncocytoma, although an extent excluding oncocytoma was not universal. Multiple chromosomal losses were most strongly supportive for chromophobe renal cell carcinoma diagnosis (65%). Less certainty was reported for chromosomal gain or a single loss. For tumors with mixed or inconclusive features, many participants use an intermediate diagnostic category (82%) that does not label the tumor as unequivocally benign or malignant, typically “oncocytic neoplasm” or “tumor” with comment. The term “hybrid tumor” was used variably in several scenarios. A slight majority (65%) report outright diagnosis of oncocytoma in needle biopsies. The morphologic, immunohistochemical, and genetic characteristics that define oncocytic renal tumors remain incompletely understood. Further studies correlating genetics, behavior, and histology are needed to define which tumors truly warrant classification as carcinomas for patient counseling and follow-up strategies.
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    Distinct clinicopathological features in metanephric adenoma harboring BRAF mutation
    (Impact Journals, 2016-07-08) Caliò, Anna; Eble, John N.; Hes, Ondrej; Martignoni, Guido; Harari, Saul E.; Williamson, Sean R.; Brunelli, Matteo; Osunkoya, Adeboye O.; Wang, Lisha; Comperat, Eva; Lopez-Beltran, Antonio; Wang, Mingsheng; Zhang, Shaobo; Curless, Kendra L.; Post, Kristin M.; Chang, Hsim-Yee; Luchini, Claudio; Baldrige, Lee Ann; MacLennan, Gregory T.; Montironi, Rodolfo; Grignon, David J.; Cheng, Liang; Pathology and Laboratory Medicine, School of Medicine
    BRAF mutation recently has been reported in metanephric adenoma. We sought to determine the clinical and morphologic features of BRAF-mutated metanephric adenoma and to correlate BRAF mutation with BRAF V600E immunohistochemical staining results. A series of 48 metanephric adenomas and 15 epithelial-predominant nephroblastomas were analyzed for the occurrence of BRAF mutation (BRAF V600E/V600E complex, BRAF V600D, BRAF V600K and BRAF V600R) using the BRAF RGQ PCR kit (Qiagen). Immunohistochemistry was performed using monoclonal mouse antibodies against p16INK4 and VE1 (Spring Bioscience), recognizing the BRAF V600E mutant protein. Forty-one of 48 cases (85%) showed BRAF V600E mutation; none of the other BRAF variants was detected. Of 41 BRAF-mutated metanephric adenomas, 33 showed positive VE1 immunostaining (sensitivity 80%, specificity 100%); in all cases we detected p16INK4 expression regardless of BRAF mutation status. All epithelial-predominant nephroblastomas were BRAF-wild-type and none expressed VE1. The following features were associated with BRAF V600E mutation: older patients (p=0.01), female predominance (p=0.005) and the presence of a predominantly acinar architecture (p=0.003). In summary, BRAF-mutated metanephric adenomas were associated with older age, female predominance, and the presence of a predominant acinar component. A subset (20%) of BRAF-mutated metanephric adenomas was not detected by VE1 immunostaining.
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    Gene Fusion Characterization of Rare Aggressive Prostate Cancer Variants ‐ Adenosquamous Carcinoma, Pleomorphic Giant Cell Carcinoma, and Sarcomatoid Carcinoma: An Analysis of 19 Cases
    (Wiley, 2020) Alhamar, Mohamed; Vladislav, I. Tudor; Smith, Steven C.; Gao, Yuan; Cheng, Liang; Favazza, Laura A.; Alani, Ali M.; Ittmann, Michael M.; Riddle, Nicole D.; Whitely, Lisa J.; Gupta, Nilesh S.; Carskadon, Shannon; Gomez-Gelvez, Juan C.; Chitale, Dhananjay A.; Palanisamy, Nallasivam; Hes, Ondrej; Trpkov, Kiril; Williamson, Sean R.; Pathology and Laboratory Medicine, School of Medicine
    Aims We evaluated the molecular underpinnings of rare aggressive prostate cancer variants adenosquamous, pleomorphic giant cell, and sarcomatoid carcinomas. Methods and Results We retrieved 19 tumors with one or more variant(s) and performed ERG immunohistochemistry, a next‐generation sequencing assay targeting recurrent gene fusions, and fluorescence in situ hybridization (FISH) for ERG and BRAF. Divergent differentiation included: sarcomatoid (n=10), adenosquamous (n=7), and pleomorphic giant cell carcinoma (n=7). Five patients had more than one variant. Four had variants only in metastases. ERG rearrangement was detected in 9 (47%, 7 via sequencing, showing TMPRSS2‐ERG and one GRHL2‐ERG fusion, and 2 via FISH, showing rearrangement via deletion). Of these, ERG immunohistochemistry was positive in the adenocarcinoma for 8/9 (89%) but only 5/9 (56%, typically decreased) in the variant. One patient had false‐positive ERG immunohistochemistry in the sarcomatoid component despite negative FISH. Two (11%) harbored BRAF fusions (FAM131A‐BRAF and SND1‐BRAF). Conclusions ERG gene fusions are present in these rare prostate cancer variants with a close frequency to conventional prostate cancer (9/19, 47%). ERG immunohistochemistry usually detects rearrangement in the adenocarcinoma but is less sensitive for the variant histology with weak to negative staining. Adenosquamous and sarcomatoid variants particularly can occur together. Molecular assessment may be an additional tool in select cases to confirm prostatic origin of unusual tumors. The presence of 2 BRAF gene rearrangements suggests that this gene fusion may be enriched in this setting, as RAF kinase fusions have been previously reported in 1‐2% of prostate cancers.
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    Immunohistochemical characteristics of Renomedullary interstitial cell tumor: a study of 41 tumors with emphasis on differential diagnosis of mesenchymal neoplasms
    (Elsevier, 2018) Lu, Zhichun; Al-Obaidy, Khaleel; Cheng, Liang; Perry, Kyle D.; Grignon, David J.; Williamson, Sean R.; Pathology and Laboratory Medicine, School of Medicine
    Renomedullary interstitial cell tumors (RMICT) are almost always incidentally identified either at autopsy or resection of the kidney for other reasons. However, rare cases have been reported which are large, resulting in a clinical mass. The immunohistochemical phenotype of usual, incidental RMICT using modern soft tissue tumor markers in is largely unknown, however, providing little information to aid in classification of larger or atypical tumors. We retrieved 41 RMICTs from 36 patients, and studied pathologic characteristics including morphology, immunohistochemistry (S100, keratin AE1/AE3, smooth muscle actin, desmin, estrogen and progesterone receptors, calponin, CD34, CD35), and histochemical staining. Data collected included age, gender, tumor size, laterality, and indication for kidney examination. RMICTs (n = 41) were identified in 23 men and 13 women, with mean age 57 years (range 24–83), tumor sizes ranged from <1 to 13 mm (median 4 mm). Kidneys were resected for 32 tumors, 1 chronic pyelonephritis, 1 trauma, and 2 autopsies. All (41, 100%) had entrapped renal tubules, 5 (12%) of which included cystic or dilated tubules. Most (35, 85%) had collagenous fibers, all of which were negative for Congo red. RMICT demonstrates a largely negative immunohistochemical phenotype with weak to moderate labeling for smooth muscle actin and calponin that is substantially less than myofibroblastic lesions. Positive staining for estrogen and progesterone receptor is common (61%), which could overlap with mixed epithelial and stromal tumor and other entities; however, staining is typically weak. CD34 is usually negative, with occasional weak labeling, in contrast to solitary fibrous tumor.
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    Low-grade Oncocytic Tumor of Kidney (CD117 Negative, Cytokeratin 7 Positive): A Distinct Entity?
    (Wiley, 2019) Trpkov, Kiril; Williamson, Sean R.; Gao, Yuan; Martinek, Petr; Cheng, Liang; Sangoi, Ankur R.; Yilmaz, Asli; Wang, Cheng; Fraile, Pilar San Miguel; Montiel, Delia M. Perez; Bulimbasić, Stela; Rogala, Joanna; Hes, Ondrej; Pathology and Laboratory Medicine, School of Medicine
    Aim To describe a group of distinct low‐grade oncocytic renal tumors that demonstrate CD117 negative/Cytokeratin (CK) 7 positive immunoprofile. Methods and results We identified 28 such tumors from 4 large renal tumor archives. We performed immunohistochemistry for: CK7, CD117, PAX8, CD10, AMACR, e‐cadherin, CK20, CA9, AE1/AE3, vimentin, BerEP4, MOC31, CK5/6, p63, HMB45, melan A, CD15 and FH. In 14 cases we performed array CGH; in 9 cases with successful result. Median patient age was 66 years (range 49‐78 years) with a male‐to‐female ratio of 1:1.8. Median tumor size was 3 cm (range 1.1‐13.5 cm). All were single tumors, solid and tan‐brown, without a syndromic association. On microscopy, all cases showed solid and compact nested growth. There were frequent areas of edematous stroma with loosely arranged cells. The tumor cells had oncocytic cytoplasm with uniformly round to oval nuclei, but without significant irregularities, and showed only focal perinuclear halos. Negative CD117 and positive CK7 reactivity were present in all cases (in 2 cases there was focal and very weak CD117 reactivity). Uniform reactivity was found for: PAX8, AE1/AE3, e‐cadherin, BerEP4 and MOC31. Negative stains included: CA9, CK20, vimentin, CK5/6, p63, HMB45, Melan A and CD15. CD10 and AMACR were either negative or focally positive; FH was retained. On array CGH, there were frequent deletions at 19p13.3 (7/9), 1p36.33 (5/9) and 19q13.11 (4/9); disomic status was found in 2/9 cases. On follow‐up (mean 31.8 months, range 1‐118), all patients were alive with no disease progression. Conclusion Low‐grade oncocytic tumors that are CD117 negative/CK7positive demonstrate consistent and readily recognizable morphology, immunoprofile, and indolent behavior.
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    Merlin immunohistochemistry is useful in diagnosis of tumours within the spectrum of biphasic hyalinizing psammomatous renal cell carcinoma
    (Wiley, 2022-11) Collins, Katrina; Hwang, Michael; Antic, Tatjana; Paintal, Ajit; Argani, Pedram; Matoso, Andres; Gopinath, Arun; Baskovich, Brett; Mehra, Rohit; Williamson, Sean R.; Idrees, Muhammad T.; Barletta, Justine A.; Anderson, William J.; Hirsch, Michelle S.; Hornick , Jason L.; Acosta, Andres M.; Pathology and Laboratory Medicine, School of Medicine
    Aims: Biphasic hyalinizing psammomatous (BHP) renal cell carcinoma (RCC) is a newly described emerging entity within the spectrum of papillary RCC in the WHO 2022 classification. Molecular analyses have discovered that BHP RCC consistently harbour somatic mutations in the neurofibromin 2 (NF2) gene. The NF2 gene product, merlin, is known to primarily function as a tumour suppressor. Merlin protein loss correlates closely with the presence of NF2 mutations in benign and malignant tumours arising in different sites. In the present study we explored the role of merlin immunohistochemistry (IHC) in tumours within the spectrum of BHP RCC to determine the diagnostic utility of this marker. Materials and methods: We performed merlin IHC in 13 BHP RCC, 18 papillary RCC, 10 TFE3-translocation RCC, 15 TFEB-altered RCC (including 13 TFEB-rearranged and 2 TFEB-amplified), and 10 mucinous tubular and spindle cell carcinomas of unknown mutational status. Results: Unequivocal loss of merlin expression in >90% of the tumour cells was observed in 12/13 BHP-RCC (92%), with the remaining tumour demonstrating weak focal cytoplasmic expression in ~10% of the tumour. In contrast, merlin was diffusely or multifocally expressed in all papillary RCC, TFE3-translocation RCC, and TFEB-altered RCC, as well as in 70% of mucinous tubular and spindle carcinomas. Conclusions: In this study, merlin IHC was ~92% sensitive and ~94% specific for BHP RCC. These data suggest that merlin IHC is a reliable surrogate marker for the presence of underlying NF2 gene inactivation, being diagnostically useful to identify BHP RCC.
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    Molecular pathology of urogenital tumors : Recommendations from the 2019 International Society of Urological Pathology (ISUP) Consensus Conference
    (SpringerLink, 2021-05) Hommerding, Oliver; Allory, Yves; Argani, Pedram; Bismar, Tarek A.; Bubendorf, Lukas; Canete-Portillo, Sofía; Chaux, Alcides; Chen, Ying-Bei; Cheng, Liang; Cubilla, Antonio L.; Egevad, Lars; Gill, Anthony J.; Grignon, David J.; Hartmann, Arndt; Hes, Ondrej; Idrees, Muhammad T.; Kao, Chia-Sui; Knowles, Margaret A.; Looijenga, Leendert H.J.; Lotan, Tamara L.; Pritchard, Colin C.; Rubin, Mark A.; Tomlins, Scott A.; Van der Kwast, Theodorus H.; Velazquez, Elsa F.; Warrick, Joshua I.; Williamson, Sean R.; Kristiansen, Glen; Pathology and Laboratory Medicine, School of Medicine
    Comprehensive understanding of molecular principles in cancer and the diversification of oncological therapy promise individual therapeutic concepts, which have not yet found their way into urogenital cancer therapy. In March 2019 the International Society of Urogenital Pathology (ISUP) therefore held a consensus conference on recommendations for molecular diagnostics of genitourinary tumors, which were published in five separate manuscripts and are summarized in this article.In preparation for the conference, a comprehensive survey of current practices for molecular testing of urogenital tumors was carried out by members of the ISUP. At the conference, the results and the corresponding background information were presented by five working groups and recommendations for action for diagnostics were developed. An agreement between 66% of the conference participants was defined as consensus.
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    Morphologic Spectrum of Renal Cell Carcinoma, Unclassified: An Analysis of 136 Cases
    (Wiley, 2017) Perrino, Carmen M.; Grignon, David J.; Williamson, Sean R.; Idrees, Muhammad T.; Eble, John N.; Cheng, Liang; Department of Pathology and Laboratory Medicine, School of Medicine
    Aims Renal cell carcinoma, unclassified (RCCU) is a category that includes a morphologically and biologically heterogeneous group of tumors that are unable to be diagnosed as other well-defined entities. We aim to describe the morphologic findings of tumors within this category and to determine the most frequent morphologic features leading to classification difficulty. Methods and results One hundred and thirty-six cases of RCCU were examined. Patients ranged in age from 23 to 87 years. Seventy-seven patients were men and 59 were women. International Society of Urological Pathology (ISUP) grade was most commonly 3 (n=66), followed by 2 (n=42) and 4 (n=28). Tumor size ranged from 0.6 cm to 24.9 cm. The AJCC pathologic T categories included pT1a (n=50), pT1b (n=14), pT2a (n=7), pT2b (n=4), pT3a (n=50), and pT4 (n=9). Forty-four cases included lymph node(s), of which 41% (n=18) had metastases. Tumors were assessed for a variety of histologic features and assigned to the following morphologic groups: predominantly oncocytoma/chromophobe RCC-like; clear cell RCC-like; papillary RCC-like; collecting duct-like; and pure sarcomatoid differentiation. The majority of the oncocytoma/chromophobe and clear cell RCC-like phenotypes were low stage (pT1 or pT2). The papillary RCC-like, collecting duct-like, and pure sarcomatoid phenotypes were mostly high stage (pT3 or pT4). Conclusions RCCU is a term that encompasses tumors with a variety of morphologic features and a wide biologic spectrum. The most common source of diagnostic difficulty was tumors composed of predominantly eosinophilic cells.
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    Müllerian Adenosarcoma of the Urinary Bladder: Clinicopathologic and Immunohistochemical Features with Novel Genetic Aberrations
    (Elsevier, 2017-04) Sanfrancesco, Joseph; Williamson, Sean R.; Kum, Jennifer B.; Zhang, Shaobo; Wang, Mingsheng; Lopez-Beltran, Antonio; Montironi, Rodolfo; Gardner, Thomas A.; Cheng, Liang; Department of Pathology and Laboratory Medicine, IU School of Medicine
    Müllerian adenosarcoma is a biphasic neoplasm most commonly of the uterus and less frequently of the ovary. It has been rarely described to occur in other sites such as peritoneum and liver. In this study, we report the clinicopathologic, immunohistochemical and molecular features of a primary müllerian adenosarcoma of the urinary bladder in a 62-year-old woman. To our knowledge, this is the first report of müllerian adenosarcoma primary to the urinary bladder in the literature. Light microscopy showed a biphasic epithelial and stromal tumor with benign-appearing glands surrounded by endometrial-type stroma that is densely cellular with increased mitotic figures. The stroma surrounding the glands is more cellular than the intervening areas, which are more loose and edematous. Immunohistochemistry profile included positive staining for Pax2/8 within the glands, for CD10 and WT-1 within the spindled stroma, and for estrogen and progesterone receptors in both. Staining for desmin, GATA3, p63, and human papilloma virus (HPV) is negative. Molecular analyses identified mutations in AKT1 E17K, FLT3 D835N, KRAS G12D and HRAS G12S. These novel molecular aberrations have yet to be reported in the medical literature. X chromosome inactivation analysis revealed a clonal pattern in the stromal component and a non-clonal pattern in the epithelial component. Currently, the patient is disease/recurrence-free after regular follow-up of approximately 84 months. This case represents the first reported diagnosis of müllerian adenosarcoma arising in the urinary bladder with extensive clinicopathologic, immunohistochemical, and molecular analyses.
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    New developments in existing WHO entities and evolving molecular concepts: The Genitourinary Pathology Society (GUPS) update on renal neoplasia
    (Elsevier, 2021) Trpkov, Kiril; Hes, Ondrej; Williamson, Sean R.; Adeniran, Adebowale J.; Agaimy, Abbas; Alaghehbandan, Reza; Amin, Mahul B.; Argani, Pedram; Chen, Ying-Bei; Cheng, Liang; Epstein, Jonathan I.; Cheville, John C.; Comperat, Eva; Werneck da Cunha, Isabela; Gordetsky, Jennifer B.; Gupta, Sounak; He, Huiying; Hirsch, Michelle S.; Humphrey, Peter A.; Kapur, Payal; Kojima, Fumiyoshi; Lopez, Jose I.; Maclean, Fiona; Magi-Galluzzi, Cristina; McKenney, Jesse K.; Mehra, Rohit; Menon, Santosh; Netto, George J.; Przybycin, Christopher G.; Rao, Priya; Rao, Qiu; Reuter, Victor E.; Saleeb, Rola M.; Shah, Rajal B.; Smith, Steven C.; Tickoo, Satish; Tretiakova, Maria S.; True, Lawrence; Verkarre, Virginie; Wobker, Sara E.; Zhou, Ming; Gill, Anthony J.; Pathology and Laboratory Medicine, School of Medicine
    The Genitourinary Pathology Society (GUPS) reviewed recent advances in renal neoplasia, particularly post-2016 World Health Organization (WHO) classification, to provide an update on existing entities, including diagnostic criteria, molecular correlates, and updated nomenclature. Key prognostic features for clear cell renal cell carcinoma (RCC) remain WHO/ISUP grade, AJCC/pTNM stage, coagulative necrosis, and rhabdoid and sarcomatoid differentiation. Accrual of subclonal genetic alterations in clear cell RCC including SETD2, PBRM1, BAP1, loss of chromosome 14q and 9p are associated with variable prognosis, patterns of metastasis, and vulnerability to therapies. Recent National Comprehensive Cancer Network (NCCN) guidelines increasingly adopt immunotherapeutic agents in advanced RCC, including RCC with rhabdoid and sarcomatoid changes. Papillary RCC subtyping is no longer recommended, as WHO/ISUP grade and tumor architecture better predict outcome. New papillary RCC variants/patterns include biphasic, solid, Warthin-like, and papillary renal neoplasm with reverse polarity. For tumors with 'borderline' features between oncocytoma and chromophobe RCC, a term "oncocytic renal neoplasm of low malignant potential, not further classified" is proposed. Clear cell papillary RCC may warrant reclassification as a tumor of low malignant potential. Tubulocystic RCC should only be diagnosed when morphologically pure. MiTF family translocation RCCs exhibit varied morphologic patterns and fusion partners. TFEB-amplified RCC occurs in older patients and is associated with more aggressive behavior. Acquired cystic disease (ACD) RCC-like cysts are likely precursors of ACD-RCC. The diagnosis of renal medullary carcinoma requires a negative SMARCB1 (INI-1) expression and sickle cell trait/disease. Mucinous tubular and spindle cell carcinoma (MTSCC) can be distinguished from papillary RCC with overlapping morphology by losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22. MTSCC with adverse histologic features shows frequent CDKN2A/2B (9p) deletions. BRAF mutations unify the metanephric family of tumors. The term "fumarate hydratase deficient RCC" ("FH-deficient RCC") is preferred over "hereditary leiomyomatosis and RCC syndrome-associated RCC". A low threshold for FH, 2SC, and SDHB immunohistochemistry is recommended in difficult to classify RCCs, particularly those with eosinophilic morphology, occurring in younger patients. Current evidence does not support existence of a unique tumor subtype occurring after chemotherapy/radiation in early childhood.