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Hornick JL, Plaza JA, Mentzel T, Gru AA, Brenn T. PRAME Expression Is a Useful Tool in the Diagnosis of Primary and Metastatic Dedifferentiated and Undifferentiated Melanoma. Am J Surg Pathol 2023; 47:1390-1397. [PMID: 37727938 DOI: 10.1097/pas.0000000000002125] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Although mostly recognized in the metastatic setting dedifferentiated and undifferentiated melanomas are increasingly recognized as cutaneous and, less commonly, mucosal primary tumors. Their diagnosis is challenging and dependent on sampling and recognition of a conventional melanoma precursor and/or detection of a mutation in a conventional melanoma driver gene. PRAME immunohistochemistry has recently become an important ancillary tool in the separation of melanoma from benign nevi, but no comprehensive studies exist regarding its value in the detection of dedifferentiated and undifferentiated melanomas and their separation from atypical fibroxanthoma and pleomorphic dermal sarcoma, the main differential diagnoses on sun-damaged skin. After retrieval from archival files, we performed PRAME immunohistochemistry on 11 primary and 10 metastatic dedifferentiated and undifferentiated melanomas, 11 atypical fibroxanthomas, and 10 pleomorphic dermal sarcomas. Nuclear staining was assigned extent (ranging from 0 to 4 and reflecting the percentage of PRAME-positive tumor nuclei) and intensity scores (graded as absent, weak, moderate, and strong, with assigned scores ranging from 0 to 3) with combined scores ranging from 0 to 7. Both primary and metastatic dedifferentiated and undifferentiated melanomas showed strong and diffuse nuclear PRAME staining with median combined scores of 7. Strong and diffuse staining was also seen in all conventional melanoma precursors except for desmoplastic melanoma. In contrast, PRAME staining in atypical fibroxanthoma and pleomorphic dermal sarcoma was patchy and weak with median combined scores of 2. Our data emphasize the diagnostic utility of PRAME staining as a first screening tool in the detection and workup of dedifferentiated and undifferentiated melanomas, both in the primary and metastatic settings. PRAME immunohistochemistry is particularly helpful as it is also positive in tumors without a recognizable conventional melanoma precursor and in those associated with desmoplastic melanomas, where PRAME is typically found to be negative.
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Affiliation(s)
- Jason L Hornick
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Jose A Plaza
- Division of Dermatopathology, Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Thomas Mentzel
- MVZ Dermatopathologie Friedrichshafen/Bodensee PartG, Friedrichshafen, Germany
| | - Alejandro A Gru
- Department of Pathology, University of Virginia, Charlottesville, VA
| | - Thomas Brenn
- Department of Pathology and Laboratory Medicine
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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2
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Wiedemeyer K, Brenn T. Dedifferentiated and undifferentiated melanomas: a practical approach to a challenging diagnosis. Hum Pathol 2023; 140:22-31. [PMID: 37001740 DOI: 10.1016/j.humpath.2023.03.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023]
Abstract
Dedifferentiation, defined as the loss of cellular features of terminal differentiation resulting in a more primitive, unspecialized phenotype, is a rare phenomenon in melanoma and more commonly observed in the metastatic setting than in primary melanomas. The diagnosis of dedifferentiated melanoma poses a significant challenge, and the tumors need to be carefully sampled and worked up to identify any residual morphologic, immunohistochemical, or molecular evidence of their melanocytic lineage. This article reviews our current knowledge of the clinical, histopathological, immunohistochemical, and molecular features of these rare tumors and provides a practical diagnostic approach and discussion of the relevant differential diagnoses and associated diagnostic pitfalls.
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Affiliation(s)
- Katharina Wiedemeyer
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB T2L 2K8, Canada
| | - Thomas Brenn
- Departments of Pathology and Laboratory Medicine and Medicine, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2L 2K8, Canada.
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Rothrock AT, Hameed N, Cho WC, Nagarajan P, Ivan D, Torres-Cabala CA, Prieto VG, Curry JL, Aung PP. BRAF V600E immunohistochemistry as a useful tool in the diagnosis of melanomas with ambiguous morphologies and immunophenotypes. J Cutan Pathol 2023; 50:223-229. [PMID: 36377266 DOI: 10.1111/cup.14359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 11/04/2022] [Accepted: 11/13/2022] [Indexed: 11/17/2022]
Abstract
We report three melanoma cases in which BRAF V600E immunohistochemistry (IHC) was valuable for diagnosis. Patient 1: In a patient with a history of primary melanoma on the chest and metastatic melanoma to right breast after undergoing multiple local and systemic therapies, a lung metastasis exhibited chondroid differentiation, aberrant myofibroblastic marker expression, and rare pancytokeratin positivity, without melanocytic marker expression. Patient 2: After targeted and immunotherapy for primary melanoma on the scalp as well as regional and distant metastatic melanoma, an omental metastasis showed CDX2-positive glandular structures that were negative for melanocytic markers. It was initially misdiagnosed as primary gastrointestinal adenocarcinoma. Patient 3: A patient with history of melanoma showing epithelioid morphology on the right thigh presented with multiple soft tissue nodules on skin, lymph nodes and internal organs after being lost to follow-up for 4 years. A biopsy specimen from the right thigh showed spindled cells with scattered pancytokeratin cocktail positivity and ambiguous staining for melanocytic markers. For melanomas with ambiguous morphologies and/or immunophenotypes in each of the three patients, BRAF V600E expression by IHC was maintained in both primary and metastatic melanoma specimens examined. These cases highlight the utility of BRAF V600E IHC in the diagnosis of melanoma.
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Affiliation(s)
- Aimi T Rothrock
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Pathology and Laboratory Medicine, Albany Medical College, Albany, New York, USA
| | - Nadia Hameed
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Woo Cheal Cho
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Priyadharsini Nagarajan
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Doina Ivan
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Carlos A Torres-Cabala
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Victor G Prieto
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Jonathan L Curry
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Phyu P Aung
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Mennens F, Van Herck Y, Sciot R, Vanden Bempt I, Boecxstaens V, Garmyn M, Bechter O. Melanoma cell plasticity poses diagnostic challenges: a case series. Melanoma Res 2022; 32:428-439. [PMID: 36125893 DOI: 10.1097/cmr.0000000000000852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Phenotype switching is an emerging concept in melanoma research and deals with the cancer cell plasticity. In this paper, we present five cases of patients with metastatic malignant melanoma where the tumor underwent dramatic morphological and immunohistochemical changes thereby mimicking other types of malignancies. The diagnosis of melanoma in all these cases was based on the mutational profile of the tumor assessed by next-generation sequencing compared to the primary lesion or local regional lymph nodes. These cases highlight the importance of thorough diagnostic measures in patients with metastatic melanoma who show progressive disease and where basic pathological assessment shows a diagnostic discrepancy.
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Affiliation(s)
| | | | | | | | | | - Maria Garmyn
- Dermatology, University Hospitals Leuven, Leuven, Belgium
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5
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Kamata M, Minamisaka T, Imura J, Saitoh K, Shimomura A, Noguchi A. A Case of Dedifferentiated Melanoma With Lymph Node Metastasis Where Molecular Biological Tests Were Useful for Diagnosis. Cureus 2022; 14:e21644. [PMID: 35233321 PMCID: PMC8881242 DOI: 10.7759/cureus.21644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2022] [Indexed: 11/05/2022] Open
Abstract
Malignant melanoma is known to have an altered phenotype and loss of differentiation markers for melanoma due to metastasis. Here, we report a case in which the expression of the immunohistochemical markers for melanoma was changed due to lymph node metastasis of primary cutaneous malignant melanoma. The patient, a male in his 60s, was diagnosed with malignant melanoma after undergoing excision of a skin mass. The additional excision specimen showed a small number of tumor cell clusters infiltrating the dermis. The biopsied lymph node showed completely different histological findings from those of the skin lesion and consisted of spindle-shaped tumor cells. An immunohistochemical study revealed no significant positive reactions in the lymph node tissue indicative of melanoma. The additional genetic study revealed BRAF V600e mutations in both the primary tumor and a lymph node. Together with the histological findings, the diagnosis was of metastasis of dedifferentiated melanoma to a lymph node. In summary, there is a risk of underestimation or misdiagnosis of melanoma as undifferentiated sarcoma or other tumors when melanoma metastasizes to lymph nodes and findings show a dedifferentiated or undifferentiated tumor. Therefore, as in this case, it is necessary to add a genetic study in order to make a comprehensive judgment.
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Ferreira I, Arends MJ, Weyden L, Adams DJ, Brenn T. Primary de‐differentiated, trans‐differentiated and undifferentiated melanomas: overview of the clinicopathological, immunohistochemical and molecular spectrum. Histopathology 2021; 80:135-149. [PMID: 34958502 DOI: 10.1111/his.14545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/14/2021] [Accepted: 08/16/2021] [Indexed: 12/20/2022]
Affiliation(s)
- Ingrid Ferreira
- Experimental Cancer Genetics Wellcome Sanger Institute Wellcome Genome Campus Cambridge UK
- Université Libre de Bruxelles Brussels Belgium
| | - Mark J Arends
- Division of Pathology Cancer Research UK Edinburgh Centre Edinburgh UK
| | - Louise Weyden
- Experimental Cancer Genetics Wellcome Sanger Institute Wellcome Genome Campus Cambridge UK
| | - David J Adams
- Experimental Cancer Genetics Wellcome Sanger Institute Wellcome Genome Campus Cambridge UK
| | - Thomas Brenn
- Division of Pathology Cancer Research UK Edinburgh Centre Edinburgh UK
- Department of Pathology and Laboratory Medicine and the Arnie Charbonneau Cancer Institute Cumming School of Medicine University of Calgary Calgary AB Canada
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Ferreira I, Droop A, Edwards O, Wong K, Harle V, Habeeb O, Gharpuray-Pandit D, Houghton J, Wiedemeyer K, Mentzel T, Billings SD, Ko JS, Füzesi L, Mulholland K, Prusac IK, Liegl-Atzwanger B, de Saint Aubain N, Caldwell H, Riva L, van der Weyden L, Arends MJ, Brenn T, Adams DJ. The clinicopathologic spectrum and genomic landscape of de-/trans-differentiated melanoma. Mod Pathol 2021; 34:2009-2019. [PMID: 34155350 DOI: 10.1038/s41379-021-00857-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 06/03/2021] [Accepted: 06/03/2021] [Indexed: 02/03/2023]
Abstract
Dedifferentiation and transdifferentiation are rare and only poorly understood phenomena in cutaneous melanoma. To study this disease more comprehensively we have retrieved 11 primary cutaneous melanomas from our pathology archives showing biphasic features characterized by a conventional melanoma and additional areas of de-/trans-differentiation as defined by a lack of immunohistochemical expression of all conventional melanocytic markers (S-100 protein, SOX10, Melan-A, and HMB-45). The clinical, histologic, and immunohistochemical findings were recorded and follow-up was obtained. The patients were mostly elderly (median: 81 years; range: 42-86 years) without significant gender predilection, and the sun-exposed skin of the head and neck area was most commonly affected. The tumors were deeply invasive with a mean depth of 7 mm (range: 4-80 mm). The dedifferentiated component showed atypical fibroxanthoma-like features in the majority of cases (7), while additional rhabdomyosarcomatous and epithelial transdifferentiation was noted histologically and/or immunohistochemically in two tumors each. The background conventional melanoma component was of desmoplastic (4), superficial spreading (3), nodular (2), lentigo maligna (1), or spindle cell (1) types. For the seven patients with available follow-up data (median follow-up period of 25 months; range: 8-36 months), two died from their disease, and three developed metastases. Next-generation sequencing of the cohort revealed somatic mutations of established melanoma drivers including mainly NF1 mutations (5) in the conventional component, which was also detected in the corresponding de-/trans-differentiated component. In summary, the diagnosis of primary cutaneous de-/trans-differentiated melanoma is challenging and depends on the morphologic identification of conventional melanoma. Molecular analysis is diagnostically helpful as the mutated gene profile is shared between the conventional and de-/trans-differentiated components. Importantly, de-/trans-differentiation does not appear to confer a more aggressive behavior.
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Affiliation(s)
- Ingrid Ferreira
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
- Université Libre de Bruxelles, Brussels, Belgium
| | - Alastair Droop
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Olivia Edwards
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Kim Wong
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Victoria Harle
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Omar Habeeb
- Department of Anatomic Pathology, Middlemore Hospital, Auckland, NZ, New Zealand
| | | | - Joseph Houghton
- Department of Pathology, Royal Victoria Hospital, Belfast, Ireland
| | - Katharina Wiedemeyer
- Department of Dermatology, University of Heidelberg, Heidelberg, Germany
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Thomas Mentzel
- Dermatopathology Friedrichshafen, Friedrichshafen, Germany
| | | | - Jennifer S Ko
- Department of Pathology, Cleveland Clinic, Cleveland, OH, USA
| | - Laszlo Füzesi
- Center for Pathology, Robert-Weixler-Straße 48a, Kempten, Germany
| | | | - Ivana Kuzmic Prusac
- Department of Pathology, University Hospital Split and Split University School of Medicine, Split, Croatia
| | - Bernadette Liegl-Atzwanger
- Diagnostic and Research Centre for Molecular Biomedicine, Diagnostic and Research Centre for Pathology, Translational Sarcoma Pathology, Comprehensive Cancer Centre Subunit Sarcoma, Medical University Graz, Graz, Austria
| | - Nicolas de Saint Aubain
- Department of Pathology, Institut Jules Bordet, Université Libre de Bruxelles, Brussels, Belgium
| | - Helen Caldwell
- Division of Pathology, Cancer Research UK Edinburgh Centre, The University of Edinburgh, Institute of Genetics and Cancer, Edinburgh, UK
| | - Laura Riva
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Louise van der Weyden
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Mark J Arends
- Division of Pathology, Cancer Research UK Edinburgh Centre, The University of Edinburgh, Institute of Genetics and Cancer, Edinburgh, UK
| | - Thomas Brenn
- Department of Pathology and Laboratory Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
- Division of Pathology, Cancer Research UK Edinburgh Centre, The University of Edinburgh, Institute of Genetics and Cancer, Edinburgh, UK.
- The Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
| | - David J Adams
- Experimental Cancer Genetics, Wellcome Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
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Dedifferentiated and Undifferentiated Melanomas: Report of 35 New Cases With Literature Review and Proposal of Diagnostic Criteria. Am J Surg Pathol 2021; 45:240-254. [PMID: 33428337 DOI: 10.1097/pas.0000000000001645] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dedifferentiated melanoma (DM) and undifferentiated melanoma (UM) is defined as a primary or metastatic melanoma showing transition between conventional and undifferentiated components (DM) or lacking histologic and immunophenotypic features of melanoma altogether (UM). The latter is impossible to verify as melanoma by conventional diagnostic tools alone. We herein describe our experience with 35 unpublished cases to expand on their morphologic, phenotypic, and genotypic spectrum, along with a review of 50 previously reported cases (total: 85) to establish the diagnostic criteria. By definition, the dedifferentiated/undifferentiated component lacked expression of 5 routinely used melanoma markers (S100, SOX10, Melan-A, HMB45, Pan-melanoma). Initial diagnoses (known in 66 cases) were undifferentiated/unclassified pleomorphic sarcoma (n=30), unclassified epithelioid malignancy (n=7), pleomorphic rhabdomyosarcoma (n=5), other specific sarcoma types (n=6), poorly differentiated carcinoma (n=2), collision tumor (n=2), atypical fibroxanthoma (n=2), and reactive osteochondromatous lesion (n=1). In only 11 cases (16.6%) was a diagnosis of melanoma considered. Three main categories were identified: The largest group (n=56) comprised patients with a history of verified previous melanoma who presented with metastatic DM or UM. Axillary or inguinal lymph nodes, soft tissue, bone, and lung were mainly affected. A melanoma-compatible mutation was detected in 35 of 48 (73%) evaluable cases: BRAF (n=20; 40.8%), and NRAS (n=15; 30.6%). The second group (n=15) had clinicopathologic features similar to group 1, but a melanoma history was lacking. Axillary lymph nodes (n=6) was the major site in this group followed by the lung, soft tissue, and multiple site involvement. For this group, NRAS mutation was much more frequent (n=9; 60%) than BRAF (n=3; 20%) and NF1 (n=1; 6.6%). The third category (n=14) comprised primary DM (12) or UM (2). A melanoma-compatible mutation was detected in only 7 cases: BRAF (n=2), NF1 (n=2), NRAS (n=2), and KIT exon 11 (n=1). This extended follow-up study highlights the high phenotypic plasticity of DM/UM and indicates significant underrecognition of this aggressive disease among general surgical pathologists. The major clues to the diagnosis of DM and UM are: (1) presence of minimal differentiated clone in DM, (2) earlier history of melanoma, (3) undifferentiated histology that does not fit any defined entity, (4) locations at sites that are unusual for undifferentiated/unclassified pleomorphic sarcoma (axilla, inguinal, neck, digestive system, etc.), (5) unusual multifocal disease typical of melanoma spread, (6) detection of a melanoma-compatible gene mutation, and (7) absence of another genuine primary (eg, anaplastic carcinoma) in other organs.
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Massi D, Mihic-Probst D, Schadendorf D, Dummer R, Mandalà M. Dedifferentiated melanomas: Morpho-phenotypic profile, genetic reprogramming and clinical implications. Cancer Treat Rev 2020; 88:102060. [PMID: 32619863 DOI: 10.1016/j.ctrv.2020.102060] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 01/12/2023]
Abstract
Phenotypic plasticity of malignant melanoma is a well-known phenomenon. Several translational studies and small case series have reported this clinical and biological entity, particularly in metastatic melanoma, showing frequent aberrant expression of non-melanocytic differentiation markers of different lineages, posing remarkable challenges due to several alternative differential diagnoses including undifferentiated carcinoma and sarcomas. When melanoma loses its typical morpho-phenotype by routinely used diagnostic immunohistochemical markers, it is defined as "dedifferentiated melanoma". Historically, this process was closely related to diagnostic interpretative difficulties. In recent years, however, dedifferentiation has been increasingly recognized as an important biological phenomenon that demonstrates the phenotypic and genetic plasticity of melanoma, and specifically the non-irreversibility of the multistep cancerogenesis. Furthermore, dedifferentiation emerged as a general hallmark of cancer evolution and a common denominator of cross-resistance to both targeted and immunotherapy. In this review, we summarize the histopathological features, the genetic and epigenetic bases underlying the dedifferentiated phenotype in melanomas and provide additional support that dedifferentiation is a mechanism of resistance to immunotherapy and targeted therapy.
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Affiliation(s)
- Daniela Massi
- Section of Anatomic Pathology, Department of Health Sciences, University of Florence, Italy
| | - Daniela Mihic-Probst
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Dirk Schadendorf
- Department of Dermatology ,University Hospital Essen, West German Cancer Center, University Duisburg-Essen and the German Cancer Consortium (DKTK), Heidelberg, Germany
| | - Reinhard Dummer
- University Hospital Zürich Skin Cancer Center, Zürich, Switzerland
| | - Mario Mandalà
- Unit of Melanoma, Division of Medical Oncology, Department of Oncology and Haematology, Papa Giovanni XXIII Cancer Center Hospital, Bergamo, Italy.
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Saggini A, Cerroni L, Casini B, Baciorri F, Cota C. Primary intrafascial desmoplastic melanoma with pseudoglandular differentiation and aberrant cytokeratins expression: An exceptional presentation. Pathol Res Pract 2019; 215:152668. [DOI: 10.1016/j.prp.2019.152668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 11/25/2022]
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Bell PD, Israel AK, Dunn AL, Liao X. Primary Dedifferentiated Amelanotic Anorectal Melanoma: Report of a Rare Case. Int J Surg Pathol 2019; 27:923-928. [DOI: 10.1177/1066896919857148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anorectal melanoma (ARM) is an uncommon aggressive malignancy that comprises 0.5% to 1.6% of all melanoma manifestations. Dedifferentiated melanoma is very rare with loss of all melanocytic differentiation markers and is usually seen in metastatic melanoma of cutaneous origin. In this article, we report the first case of primary dedifferentiated amelanotic ARM in a 68-year-old male who presented with anal discomfort that was initially treated as inflamed hemorrhoids. Physical examination revealed a large protruding anal mass, biopsy of which showed biphasic malignant tumor cells with distinct immunoprofiles: a superficial spindled/sarcomatoid component positive for SOX10 and S100, and a deeper epithelioid/rhabdoid component positive for desmin, AE1/AE3, and EMA. Both components were negative for HMB-45, Melan-A/MART-1, c-Kit, and other lineage markers. Molecular analysis by polymerase chain reaction demonstrated wild-type BRAF and KRAS genes. A diagnosis of dedifferentiated ARM was made based on the coexistence of a differentiated component (spindled: S100 and SOX10 positive) and a dedifferentiated component (epithelioid: all melanoma markers including S100 and SOX10 negative). Shortly afterwards, the patient developed extensive pulmonary and liver metastases and expired 20 days after the diagnosis was rendered, reinforcing the highly aggressive nature of this disease entity.
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Affiliation(s)
| | | | - Andrew L. Dunn
- University of Rochester Medical Center, Rochester, NY, USA
| | - Xiaoyan Liao
- University of Rochester Medical Center, Rochester, NY, USA
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Saggini A, Cota C, Lora V, Kutzner H, Rütten A, Sangüeza O, Requena L, Cerroni L. Uncommon Histopathological Variants of Malignant Melanoma. Part 2. Am J Dermatopathol 2019; 41:321-342. [PMID: 31009411 DOI: 10.1097/dad.0000000000001226] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Despite new horizons opened by recent advances in molecular pathology, histological evaluation still remains the diagnostic gold standard regarding cutaneous melanocytic neoplasms. Several histological variants of melanoma have been described, and their knowledge is crucial for accurate diagnosis and classification of cases with unusual clinico-pathological features. Uncommon histological variants of melanoma have been described based on a broad constellation of features, including architectural pattern, stromal alterations, cytological attributes, and other morphological properties. This review is aimed at providing an extensive discussion of unusual but distinctive histopathological variants of melanoma.
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Affiliation(s)
- Andrea Saggini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Carlo Cota
- San Gallicano Dermatological Institute, Rome, Italy
| | - Viviana Lora
- San Gallicano Dermatological Institute, Rome, Italy
| | - Heinz Kutzner
- Dermatopathology Friedrichshafen, Friedrichshafen, Germany
| | - Arno Rütten
- Dermatopathology Friedrichshafen, Friedrichshafen, Germany
| | - Omar Sangüeza
- Department of Pathology, Wake Forest School of Medicine, Winston Salem, NC
| | - Luis Requena
- Department of Dermatology, Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain
| | - Lorenzo Cerroni
- Research Unit Dermatopathology, Department of Dermatology, Medical University of Graz, Graz, Austria
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13
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Detection of driver mutations in BRAF can aid in diagnosis and early treatment of dedifferentiated metastatic melanoma. Mod Pathol 2019; 32:330-337. [PMID: 30315274 DOI: 10.1038/s41379-018-0161-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/18/2018] [Accepted: 09/19/2018] [Indexed: 01/01/2023]
Abstract
Dedifferentiated metastatic melanoma can pose a significant diagnostic challenge, especially if the history of primary melanoma is not known or is remote. BRAF and NRAS mutations are common melanoma driver mutations that are usually sequenced to evaluate for treatment targets. We evaluated whether BRAF and NRAS mutational testing could contribute to the diagnosis of dedifferentiated metastatic melanoma when immunostains are negative. Seven patients with melanoma who had an additional diagnosis of poorly differentiated sarcoma with negative melanocytic immunostains were tested for BRAF and NRAS mutations. Three patients showed identical BRAF mutations in the melanoma and the poorly differentiated sarcoma and hence were re-classified as metastatic dedifferentiated melanoma. In these three patients, there was an average delay of 7 months before appropriate testing, workup and treatment for metastatic melanoma was initiated. Two of these patients currently have stable metastatic disease and show sustained therapeutic response to melanoma-specific treatment including BRAF inhibitors. BRAF mutational analysis should therefore be considered in cases of poorly differentiated sarcoma, especially if there is a known history of melanoma or with unusual localization of disease. The administration of melanoma-specific treatments in such dedifferentiated cases can show therapeutic response, highlighting the importance of rendering accurate diagnoses on such cases.
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14
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Du J, Huang LL, Xu A, Zhang AL, Kong X, Ding M, Hu W, Guo ZL, Zhong W, Sun SB, Li H, Chen J, Shen Q, Xu LL, Wu HB. Undifferentiated sinonasal malignant melanoma: A case report. Oncol Lett 2018; 16:580-584. [PMID: 29930718 DOI: 10.3892/ol.2018.8662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/12/2018] [Indexed: 12/14/2022] Open
Abstract
Undifferentiated sinonasal malignant melanoma (MM) is a rare type of tumor, which can be easily misdiagnosed. The present study reports a 41-year-old male patient who presented with a 4-day history of epistaxis. Clinical examination and radiological imaging lead to the detection of a mass in the right sinonasal region. Histopathological examination revealed that the mass was composed of malignant epithelioid cells arranged in nests and sheets. These cells displayed a hemangiopericytoma-like pattern with antler-like branching vessels. Immunohistochemical staining revealed that the tumor cells exhibited negative expression of melanocytic markers. This increased the difficulty of distinguishing undifferentiated MM from other malignant tumors located in the sinonasal area, particularly undifferentiated nasopharyngeal carcinoma. The diagnosis of undifferentiated MM was determined by ultrastructures, including the mature melanosomes and premelanosomes, in tumor cells by transmission electron microscopy. The present study suggests that the analysis of cancer stem cell marker and vasculogenic mimicry may be an important auxiliary tool for the diagnosis of MM.
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Affiliation(s)
- Jun Du
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Liang-Liang Huang
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Ao Xu
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - An-Li Zhang
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Xue Kong
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Min Ding
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Wen Hu
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Zhen-Li Guo
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Wen Zhong
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Si-Bai Sun
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Heng Li
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Jie Chen
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Qian Shen
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Lu-Lu Xu
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
| | - Hai-Bo Wu
- Department of Pathology, Anhui Provincial Hospital, Hefei, Anhui 230001, P.R. China
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15
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Needle DB, Iglikova O, Miller AD. Biphasic malignant melanoma adenocarcinoma in the digit of a dog. J Vet Diagn Invest 2018; 30:315-318. [PMID: 29284381 PMCID: PMC6505858 DOI: 10.1177/1040638717752424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A 7-y-old Black Russian Terrier dog was evaluated for chronic lameness of the right forelimb and concurrent weight loss. Clinical examination revealed a pigmented mass arising from digit 4 of the right forelimb; the digit was amputated and submitted for histologic evaluation. Histologically, the neoplasm was composed of ill-defined streams, sheets, and clusters of melanocytes admixed with a distinct population of malignant epithelial cells forming glands and nests. The diagnosis was a biphasic malignant melanoma adenocarcinoma, a rarely reported neoplasm in human medicine that has not been described in veterinary medicine, to our knowledge.
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Affiliation(s)
- David B. Needle
- David B. Needle, New
Hampshire Veterinary Diagnostic Laboratory, College of Life Sciences
and Agriculture, University of New Hampshire, Durham, NH 03824.
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16
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Emanuel PO, Desman G, Tallon B. Squamous cell carcinoma with enteric adenocarcinomatous differentiation. J Cutan Pathol 2017; 44:490-493. [DOI: 10.1111/cup.12910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 02/01/2023]
Affiliation(s)
- Patrick O. Emanuel
- Department of Pathology and Molecular Medicine; University of Auckland; Auckland New Zealand
- Division of Dermatopathology, Mount Sinai Medical Center; New York New York
| | - Garrett Desman
- Division of Dermatopathology, Mount Sinai Medical Center; New York New York
| | - Ben Tallon
- Skin Dermatology Institute; Tauranga New Zealand
- Pathlab Bay of Plenty; Tauranga New Zealand
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17
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Metastatic Malignant Melanoma With Complete Loss of Differentiation Markers (Undifferentiated/Dedifferentiated Melanoma): Analysis of 14 Patients Emphasizing Phenotypic Plasticity and the Value of Molecular Testing as Surrogate Diagnostic Marker. Am J Surg Pathol 2016; 40:181-91. [PMID: 26448190 DOI: 10.1097/pas.0000000000000527] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Metastatic malignant melanoma is notorious for its phenotypic diversity and loss of differentiation markers. We herein summarized our experience with 14 metastatic melanomas showing complete loss of immunohistochemical melanocytic markers (with or without heterologous differentiation). Patients included 11 men and 3 women aged 24 to 78 years (median, 67 y). Thirteen patients had histologically confirmed primary skin melanoma, and 1 had metastatic melanoma of unknown primary. Undifferentiated metastasis was diagnosed synchronous to primary tumor (n=1), following skin melanoma by 3 months to 9 years (n=11) and preceding it by 1 year (n=1). Sites of undifferentiated metastases were axillary (3), inguinal (1), or submandibular (1) lymph nodes, digestive tract (2), bone/soft tissue (2), lung/pleura (2), and disseminated (n=3). Histology of metastases mimicked undifferentiated pleomorphic or spindle cell sarcoma with variable myxoid and giant cell areas (n=10) and cytokeratin-positive undifferentiated small cell sarcoma (n=1). Three cases showed heterologous dedifferentiation: pleomorphic rhabdomyosarcoma (n=1), teratocarcinosarcoma-like with prominent rhabdomyoblasts (n=1), and adenocarcinoma-like with metaplastic bone (n=1). All cases were negative for S100, melanoma cocktail, HMB45, Melan A, and SOX10. Other markers showed following results: smooth muscle actin (1/14), p16 (1/14), TP53 (2/12), pancytokeratin (4/14), desmin (5/14), h-caldesmon (0/9), and MDM2/CDK4 (0/5). SMARCB1 was intact in 8/8 cases. Genotyping showed BRAF(V600E) mutation (5/14), NRAS mutation (5/14), and BRAF/NRAS wild-type (4/14). In conclusion, undifferentiated/dedifferentiated metastatic melanoma is likely underrecognized and frequently mistaken for undifferentiated sarcoma or other neoplasms. Diagnosis of undifferentiated sarcoma at sites where melanoma metastasis are frequent (eg, inguinal and axillary region) should be made with great caution and warrants exploration of the remote history. Genotyping is a helpful surrogate marker in classifying such difficult cases. In the light of available targeted therapies, recognition of undifferentiated/dedifferentiated metastatic melanoma is mandatory for appropriate treatment.
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18
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Compton LA, Murphy GF, Lian CG. Diagnostic Immunohistochemistry in Cutaneous Neoplasia: An Update. Dermatopathology (Basel) 2015; 2:15-42. [PMID: 27047932 PMCID: PMC4816435 DOI: 10.1159/000377698] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Immunohistochemistry (IHC) is an important adjunct in the diagnosis of neoplastic skin diseases. In addition to the many established IHC markers currently in use, new markers continue to emerge, although their general acceptance and routine application requires robust validation. Here, we summarize the most well-established and commonly used biomarkers along with an array of newer ones reported in the past several decades that either demonstrate or hold high clinical promise in the field of cutaneous pathology. We also highlight recent applications of novel IHC markers in melanoma diagnosis including genetic mutation status markers [e.g. BRAF (v-raf murine sarcoma viral oncogene homolog B) and NRAS (neuroblastoma RAS viral oncogene homolog)] and an epigenetic alteration marker (e.g. 5-hydroxymethylcytosine). We specifically focus on the role of IHC in the differential diagnosis of cutaneous lesions that fall under the following categories: melanoma, epidermal tumors with an intraepidermal epitheliomatous pattern, spindle cell lesions of the dermis, small round blue cell tumors of the dermis, and cutaneous adnexal tumors. While IHC is a valuable tool in diagnostic dermatopathology, marker selection and interpretation must be highly informed by clinical context and the histologic differential diagnosis. With rapid progress in our understanding of the genetic and epigenetic mechanisms of tumorigenesis, new IHC markers will continue to emerge in the field of diagnostic dermatopathology.
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Affiliation(s)
- Leigh A Compton
- Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass., USA
| | - George F Murphy
- Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass., USA
| | - Christine G Lian
- Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Mass., USA
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19
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Charli-Joseph Y, Saggini A, Vemula S, Weier J, Mirza S, LeBoit PE. Primary cutaneous perivascular epithelioid cell tumor: a clinicopathological and molecular reappraisal. J Am Acad Dermatol 2014; 71:1127-36. [PMID: 25267378 DOI: 10.1016/j.jaad.2014.08.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/02/2014] [Accepted: 08/10/2014] [Indexed: 01/20/2023]
Abstract
BACKGROUND Perivascular epithelioid cell tumor (PEComa) is a rare neoplasm of uncertain histogenesis with a mixed myomelanocytic immunophenotype, rarely arising in the skin (primary cutaneous PEComa [pcPEComa]). OBJECTIVE We analyzed the clinicopathological features of 8 pcPEComas, assayed for DNA copy number changes and for initiating mutations common in melanocytic neoplasms. METHODS pcPEComas were evaluated using immunohistochemistry, comparative genomic hybridization, and DNA sequencing. RESULTS pcPEComas were erythematous nodules, mostly in the lower extremities of women (5/8), composed of large pale-staining epithelioid cells. The patient's age range was 26 to 67 (mean 46) years. The percentages of tumors staining positively were as follows: micro-ophthalmia-associated transcription factor, NKI/C3, bcl-1, E-cadherin, and cathepsin K (100%); HMB-45, 4E-binding protein 1, and CD68 (88%); smooth muscle actin and muscle-specific actin (40%); S100 (38%); calponin (20%); desmin (13%); and melan-A, SOX10, and keratin (0%). No chromosomal copy number changes or initiating mutations were identified. LIMITATIONS Small sample size is a limitation. CONCLUSIONS pcPEComas have a different molecular signature than extracutaneous tumors and are unrelated to tuberous sclerosis. However, the common expression of 4E-binding protein 1 points to a role of the mTOR pathway in their pathogenesis. Because pcPEComas are diagnostically challenging, we propose that micro-ophthalmia-associated transcription factor, NKIC3, smooth muscle actin, desmin, bcl-1, cathepsin K, and 4E-binding protein 1 can be used when evaluating a possible pcPEComa.
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Affiliation(s)
- Yann Charli-Joseph
- Pathology, University of California San Francisco, San Francisco, California; Dermatology, University of California San Francisco, San Francisco, California
| | - Andrea Saggini
- Pathology, University of California San Francisco, San Francisco, California; Dermatology, University of California San Francisco, San Francisco, California
| | - Swapna Vemula
- Pathology, University of California San Francisco, San Francisco, California
| | - Jingly Weier
- Pathology, University of California San Francisco, San Francisco, California
| | - Sonia Mirza
- Pathology, University of California San Francisco, San Francisco, California
| | - Philip E LeBoit
- Pathology, University of California San Francisco, San Francisco, California; Dermatology, University of California San Francisco, San Francisco, California; Helen A. Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California.
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20
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Shenjere P, Fisher C, Rajab R, Patnaik L, Hazell S, Thway K. Melanoma With Rhabdomyosarcomatous Differentiation. Int J Surg Pathol 2014; 22:512-9. [DOI: 10.1177/1066896914531817] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe 2 new cases of malignant melanoma with divergent rhabdomyoblastic differentiation occurring in adult patients. The patients were women aged 67 and 51 years with primary cutaneous and uterine cervical melanoma, respectively. Rhabdomyoblastic differentiation in melanoma is very rare in adult patients, and to our knowledge, only 7 such cases have been described in the world literature, of which only 4 have conclusive documentation of the presence of rhabdomyoblastic differentiation. We present the fifth and sixth cases of adult melanomas with conclusive divergent rhabdomyoblastic differentiation, including the first noncutaneous (cervical) case; we also review the literature and highlight the potential for underrecognition of this phenomenon.
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Affiliation(s)
- Patrick Shenjere
- Department of Histopathology, The Christie Hospital, Manchester, UK
| | - Cyril Fisher
- Department of Histopathology, Royal Marsden Hospital, London, UK
| | - Ramzi Rajab
- Department of Cellular Pathology, St George’s Hospital, London, UK
| | - Lipsta Patnaik
- Department of Pathology, Blackpool Teaching Hospitals NHS Foundation Trust, Blackpool, UK
| | - Steve Hazell
- Department of Histopathology, Royal Marsden Hospital, London, UK
| | - Khin Thway
- Department of Histopathology, Royal Marsden Hospital, London, UK
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21
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Bezrookove V, De Semir D, Nosrati M, Tong S, Wu C, Thummala S, Dar AA, Leong SPL, Cleaver JE, Sagebiel RW, Miller JR, Kashani-Sabet M. Prognostic impact of PHIP copy number in melanoma: linkage to ulceration. J Invest Dermatol 2013; 134:783-790. [PMID: 24005052 PMCID: PMC3945648 DOI: 10.1038/jid.2013.369] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 08/11/2013] [Accepted: 08/12/2013] [Indexed: 12/18/2022]
Abstract
Ulceration is an important prognostic factor in melanoma whose biologic basis is poorly understood. Here we assessed the prognostic impact of pleckstrin homology domain-interacting protein (PHIP) copy number and its relationship to ulceration. PHIP copy number was determined using fluorescence in situ hybridization (FISH) in a tissue microarray cohort of 238 melanomas. Elevated PHIP copy number was associated with significantly reduced DMFS (P = 0.01) and DSS (P = 0.009) by Kaplan-Meier analyses. PHIP FISH scores were independently predictive of DMFS (P = 0.03) and DSS (P = 0.03). Increased PHIP copy number was an independent predictor of ulceration status (P = 0.04). The combined impact of increased PHIP copy number and tumor vascularity on ulceration status was highly significant (P< 0.0001). Stable suppression of PHIP in human melanoma cells resulted in significantly reduced glycolytic activity in vitro, with lower expression of LDH5, HIF1A, and VEGF, and was accompanied by reduced microvessel density in vivo. These results provide further support for PHIP as a molecular prognostic marker of melanoma, and reveal a significant linkage between PHIP levels and ulceration. Moreover, they suggest that ulceration may be driven by increased glycolysis and angiogenesis.
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Affiliation(s)
- Vladimir Bezrookove
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - David De Semir
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Mehdi Nosrati
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Schuyler Tong
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Clayton Wu
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Suresh Thummala
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Altaf A Dar
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Stanley P L Leong
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - James E Cleaver
- UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, California
| | - Richard W Sagebiel
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - James R Miller
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
| | - Mohammed Kashani-Sabet
- Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, San Francisco, California
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