1
|
Roy SF, Milante R, Pissaloux D, Tirode F, Bastian BC, Fouchardière ADL, Yeh I. Spectrum of Melanocytic Tumors Harboring BRAF Gene Fusions: 58 Cases With Histomorphologic and Genetic Correlations. Mod Pathol 2023; 36:100149. [PMID: 36841436 DOI: 10.1016/j.modpat.2023.100149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 02/08/2023] [Accepted: 02/16/2023] [Indexed: 02/27/2023]
Abstract
We report a series of 58 melanocytic tumors that harbor an activating fusion of BRAF, a component of the mitogen-activated protein kinase (MAPK) signaling cascade. Cases were diagnosed as melanocytic nevus (n = 12, 21%), diagnostically ambiguous favor benign (n = 22, 38%), and diagnostically ambiguous concerning for melanoma (n = 12, 21%) or melanoma (n = 12, 21%). Three main histopathologic patterns were observed. The first pattern (buckshot fibrosis) was characterized by large, epithelioid melanocytes arrayed as single cells or "buckshot" within marked stromal desmoplasia. The second pattern (cords in whorled fibrosis) demonstrated polypoid growth with a whorled arrangement of cords and single melanocytes within desmoplasia. The third pattern (spindle-cell fascicles) showed fascicular growth of spindled melanocytes. Cytomorphologic features characteristic of Spitz nevi were observed in most cases (n = 50, 86%). Most of the cases (n = 54, or 93%) showed stromal desmoplasia. Histomorphology alone was not sufficient in distinguishing benign from malignant melanocytic tumors with BRAF fusion gene because the only histopathologic features more commonly associated with a diagnosis of malignancy included dermal mitoses (P = .046) and transepidermal elimination of melanocytes (P = .013). BRAF fusion kinases are targetable by kinase inhibitors and, thus, should be considered as relevant genetic alterations in the molecular workup of melanomas. Recognizing the 3 main histopathologic patterns of melanocytic tumors with BRAF fusion gene will aid in directing ancillary testing.
Collapse
Affiliation(s)
- Simon F Roy
- Department of Dermatology, Yale School of Medicine, New Haven, Connecticut
| | - Riza Milante
- Department of Dermatology, University of California in San Francisco, San Francisco, California
| | - Daniel Pissaloux
- Department of Biopathology, Centre Léon Bérard, Lyon, France; University of Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5286, INSERM U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Franck Tirode
- University of Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5286, INSERM U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Boris C Bastian
- Department of Dermatology, University of California in San Francisco, San Francisco, California; Department of Pathology, University of California in San Francisco, San Francisco, California
| | - Arnaud de la Fouchardière
- Department of Biopathology, Centre Léon Bérard, Lyon, France; University of Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5286, INSERM U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Iwei Yeh
- Department of Dermatology, University of California in San Francisco, San Francisco, California; Department of Pathology, University of California in San Francisco, San Francisco, California.
| |
Collapse
|
2
|
Massoth LR, Hung YP, Ferry JA, Hasserjian RP, Nardi V, Nielsen GP, Sadigh S, Venkataraman V, Selig M, Friedmann AM, Samore W, Killian JK, Milante R, Giessinger J, Foley-Peres K, Marcus C, Severson E, Duncan D, Sivakumar S, Ross JS, Desphande V, Ramkissoon SH, Vergilio JA, Louissaint A, Zukerberg LR, Williams EA. Histiocytic and Dendritic Cell Sarcomas of Hematopoietic Origin Share Targetable Genomic Alterations Distinct from Follicular Dendritic Cell Sarcoma. Oncologist 2021; 26:e1263-e1272. [PMID: 33904632 PMCID: PMC8265357 DOI: 10.1002/onco.13801] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/16/2021] [Indexed: 12/18/2022] Open
Abstract
Background Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from monocytic or dendritic cell lineage. Whereas the genomic features for Langerhans cell histiocytosis and Erdheim‐Chester disease have been well described, other less common and often aggressive tumors in this broad category remain poorly characterized, and comparison studies across the World Health Organization diagnostic categories are lacking. Methods Tumor samples from a total of 102 patient cases within four major subtypes of malignant histiocytic and dendritic cell neoplasms, including 44 follicular dendritic cell sarcomas (FDCSs), 41 histiocytic sarcomas (HSs), 7 interdigitating dendritic cell sarcomas (IDCSs), and 10 Langerhans cell sarcomas (LCSs), underwent hybridization capture with analysis of up to 406 cancer‐related genes. Results Among the entire cohort of 102 patients, CDKN2A mutations were most frequent across subtypes and made up 32% of cases, followed by TP53 mutations (22%). Mitogen‐activated protein kinase (MAPK) pathway mutations were present and enriched among the malignant histiocytosis (M) group (HS, IDCS, and LCS) but absent in FDCS (72% vs. 0%; p < .0001). In contrast, NF‐κB pathway mutations were frequent in FDCSs but rare in M group histiocytoses (61% vs. 12%; p < .0001). Tumor mutational burden was significantly higher in M group histiocytoses as compared with FDCSs (median 4.0/Mb vs. 2.4/Mb; p = .012). We also describe a pediatric patient with recurrent secondary histiocytic sarcoma treated with targeted therapy and interrogated by molecular analysis to identify mechanisms of therapeutic resistance. Conclusion A total of 42 patient tumors (41%) harbored pathogenic mutations that were potentially targetable by approved and/or investigative therapies. Our findings highlight the potential value of molecular testing to enable precise tumor classification, identify candidate oncogenic drivers, and define personalized therapeutic options for patients with these aggressive tumors. Implications for Practice This study presents comprehensive genomic profiling results on 102 patient cases within four major subtypes of malignant histiocytic and dendritic cell neoplasms, including 44 follicular dendritic cell sarcomas (FDCSs), 41 histiocytic sarcomas (HSs), 7 interdigitating dendritic cell sarcomas (IDCSs), and 10 Langerhans cell sarcomas (LCSs). MAPK pathway mutations were present and enriched among the malignant histiocytosis (M) group (HS, IDCS, and LCS) but absent in FDCSs. In contrast, NF‐κB pathway mutations were frequent in FDCSs but rare in M group histiocytosis. A total of 42 patient tumors (41%) harbored pathogenic mutations that were potentially targetable by approved and/or investigative therapies. Histiocytic and dendritic cell neoplasms are a diverse group of tumors arising from the monocytic or dendritic cell lineage. This article presents the molecular characteristics of the four major subtypes of malignant histiocytic and dendritic cell neoplasms, focusing on genomic alterations that could represent therapeutic targets.
Collapse
Affiliation(s)
- Lucas R Massoth
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Yin P Hung
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Judith A Ferry
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Robert P Hasserjian
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Valentina Nardi
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - G Petur Nielsen
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Sam Sadigh
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Vinayak Venkataraman
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Martin Selig
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Alison M Friedmann
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Wesley Samore
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Riza Milante
- Department of Dermatology, Jose R. Reyes Memorial Medical Center, Manila, Philippines
| | - Joseph Giessinger
- A.T. Still University School of Osteopathic Medicine, Mesa, Arizona, USA
| | - Kathleen Foley-Peres
- Department of Biology, Bristol Community College, Fall River, Massachusetts, USA
| | - Chelsea Marcus
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA
| | - Eric Severson
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA
| | - Daniel Duncan
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA
| | | | - Jeffrey S Ross
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA.,Department of Pathology, State University of New York Upstate Medical University, Syracuse, New York, USA
| | - Vikram Desphande
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Shakti H Ramkissoon
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA.,Wake Forest Comprehensive Cancer Center and Department of Pathology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | | | - Abner Louissaint
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Lawrence R Zukerberg
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Erik A Williams
- Foundation Medicine, Inc., Cambridge, Massachusetts, USA.,Department of Pathology, Department of Dermatology, UCSF Dermatopathology Service, University of California San Francisco, San Francisco, California, USA
| |
Collapse
|