Browsing by Author "Anderson, William J."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Clinicopathologic and molecular spectrum of testicular sex cord-stromal tumors not amenable to specific histopathologic subclassification
    (Elsevier, 2022-12) Siegmund , Stephanie E.; Sholl , Lynette M.; Tsai , Harrison K.; Yang, Yiying; Vasudevaraja, Varshini; Tran, Ivy; Snuderl, Matija; Fletcher, Christopher D. M.; Cornejo, Kristine M.; Idrees, Muhammad T.; Al-Obaidy, Khaleel I.; Collins , Katrina; Gordetsky, Jennifer B.; Wobker, Sara E.; Hirsch, Michelle S.; Trpkov , Kiril; Yilmaz , Asli; Anderson, William J.; Quiroga-Garza, Gabriela; Magi-Galluzzi, Cristina; Canete-Portillo, Sofia; Acosta , Andres M.; Pathology and Laboratory Medicine, School of Medicine
    A subset of testicular sex cord-stromal tumors (SCST), which includes neoplasms with mixed histology, cannot be classified into a specific histologic subtype. This study evaluated the clinicopathologic, immunophenotypic and molecular features of 26 SCST not amenable to specific classification by expert uropathologists. Median age at diagnosis was 43 years and median tumor size was 2.4 cm. Follow-up information was available for 18 (69%) patients, with evidence of an aggressive clinical course in 6 patients (4 alive with disease, 2 dead of disease 3 months and 6 months after orchiectomy). Microscopically, SCST not amenable to specific classification demonstrated monophasic epithelioid (9/26, 35%), monophasic spindle cell (5/26, 19%), and biphasic or mixed histology (12/26, 46%). One or more aggressive histopathologic features were seen in 11 cases. DNA sequencing was successful in 22 tumors. Pathogenic CTNNB1 and APC alterations were seen in 7 (33%) and 2 (10%) cases, respectively, with additional variants (e.g., CDKN2A, RB1, TP53, BRCA2) being identified in individual cases. Combined evaluation of morphology, sequencing data and beta-catenin immunohistochemistry resulted in reclassification of 6 (23%) tumors as Sertoli cell tumor, not otherwise specified. This was supported by comparing the methylation profiles of a subset of these tumors and those of typical Sertoli cell tumors. Additionally, a subset of 5 neoplasms (19%) with spindle cell or biphasic histology and SMA expression was characterized by hyperdiploid genomes with recurrent chromosomal gains and absence of driver mutations, possibly representing a distinct tumor type. The SCST that remained not amenable to specific histologic classification (15/26, 58%) were enriched for aggressive histologic features and malignant clinical behavior. In conclusion, this study demonstrated that a subset of testicular SCST that were originally not amenable to specific classification could be reclassified by combined evaluation of morphology, immunohistochemistry and molecular data.
  • Thumbnail Image
    Item
    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.