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Bishop JA, Thompson LDR, Siegele B, Gagan J, Mansour M, Chernock RD, Rooper LM. Mucoepidermoid carcinoma may be devoid of squamoid cells by immunohistochemistry: expanding the histologic and immunohistochemical spectrum of MAML2- rearranged salivary gland tumours. Histopathology 2023; 82:305-313. [PMID: 36208053 DOI: 10.1111/his.14817] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 12/13/2022]
Abstract
Mucoepidermoid carcinoma (MEC) is historically defined by a mix of squamoid, intermediate, and mucous cells, but we have recently encountered several cases lacking immunoreactivity for squamous markers p40, p63, and CK5/6 despite MAML2 fusions. This study will characterise these unique tumours. Ten MEC were collected arising from the parotid gland (n = 4), submandibular gland (n = 2), nasopharynx (n = 1), base of tongue (n = 1), bronchus (n = 1), and trachea (n = 1). Six tumours were low-grade, two intermediate-grade, one high-grade, and one demonstrated low-grade areas with high-grade transformation. Four cases were oncocytic, four had clear-cell features, two had spindle cell features, and one high-grade MEC had prominent solid, cord-like, and micropapillary features. The tumours were negative for p40 (10/10), p63 (10/10), and CK5/6 (9/9). Targeted RNA sequencing demonstrated CRTC1::MAML2 in five cases, CRTC3::MAML2 in two, and a novel MAML2::CEP126 in the unusual high-grade case. In two cases with insufficient RNA, MAML2 fluorescence in situ hybridisation (FISH) showed rearrangement. Genetically-confirmed MEC may lack overt squamous differentiation by histology and immunohistochemistry. While most cases harboured canonical fusions and fit within the spectra of MEC variants with oncocytic, clear cell, and/or spindle cell features, one had a novel MAML2::CEP126 fusion and unusual morphology. In MEC without squamoid cells, the use of immunohistochemistry may hinder, rather than aid, the correct diagnosis. In such cases, MAML2 analysis is most useful. The historical definition of MEC as a carcinoma with squamoid, intermediate and mucous cells should be revisited.
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Affiliation(s)
- Justin A Bishop
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Bradford Siegele
- Department of Pathology and Laboratory Services, Children's Hospital Colorado, Aurora, CO, USA
| | - Jeffrey Gagan
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Mena Mansour
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Rebecca D Chernock
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Lisa M Rooper
- Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD, USA
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Bishop JA, Sajed DP, Weinreb I, Dickson BC, Bilodeau EA, Agaimy A, Franchi A, Khurram SA, Da Forno P, Robledo J, Kalmar JR, Aguirre S, Krane JF, Tapia JL, Kiss K, Cordell K, Rosebush M, Barrett AW, Oda D, Assaad A, Nagao T, Kawakami F, Nakaguro M, Zahir I, Wakeman K, Ihrler S, Chenevert J, Lin YL, Westra WH, Gagan J, Rooper LM. Microsecretory Adenocarcinoma of Salivary Glands: An Expanded Series of 24 Cases. Head Neck Pathol 2021; 15:1192-1201. [PMID: 33982215 PMCID: PMC8633253 DOI: 10.1007/s12105-021-01331-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 04/28/2021] [Indexed: 10/21/2022]
Abstract
Microsecretory adenocarcinoma (MSA) is a recently described salivary gland tumor with a characteristic histologic and immunophenotypic profile and recurrent MEF2C-SS18 fusions. Because only six cases of MSA have been published, its complete clinicopathologic spectrum is unclear, and its biologic behavior has not been documented. Here, we present an updated and expanded experience of 24 MSA cases. All cases of MSA were obtained from the authors' files. Immunohistochemistry for S100, SOX10, p63, p40, SMA, calponin, and mammaglobin was performed. Molecular analysis was performed by targeted RNA sequencing, SS18 break apart fluorescence in situ hybridization, and/or reverse transcriptase polymerase chain reaction for MEF2C-SS18 fusion. Clinical follow-up was obtained from medical records. A total of 24 MSA cases were collected, from 13 women and 11 men, ranging from 17 to 83 years (mean 49.5 years). The vast majority (23 of 24) arose in the oral cavity, with the palate (n = 14) and buccal mucosa (n = 6) as the most frequent subsites. Tumors showed consistent histologic features including: (1) microcystic tubules, (2) flattened intercalated duct-like cells, (3) monotonous oval hyperchromatic nuclei, (4) abundant basophilic luminal secretions, (5) fibromyxoid stroma, and (6) circumscribed borders with subtle infiltration. The tumors were very consistently positive for S100 (24 of 24), p63 (24 of 24), and SOX10 (14 of 14) and negative for p40 (0 of 21), calponin (0 of 12) and mammaglobin (0 of 16), while SMA (4 of 20) was variable. MEF2C-SS18 fusion was demonstrated in 21 of 24 cases; in the remaining 3 cases with insufficient RNA, SS18 break apart FISH was positive. Treatment information was available in 17 cases, all of which were managed with surgery only. In 14 cases with follow-up (1-216 months, mean 30), no cases recurred or metastasized. MSA is a distinct salivary gland neoplasm with remarkably consistent clinical, histologic, immunophenotypic, and genetic features that generally behaves in an indolent manner following surgery alone. These observations solidify MSA as a unique, low-grade salivary gland carcinoma that warrants inclusion in the next version of the WHO classification of head and neck tumors.
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Affiliation(s)
- Justin A Bishop
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Dipti P Sajed
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Ilan Weinreb
- Department of Pathology, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Brendan C Dickson
- Department of Pathology & Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Elizabeth A Bilodeau
- Department of Diagnostic Sciences, School of Dental Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Abbas Agaimy
- Institute of Pathology, University Hospital of Erlangen, Erlangen, Germany
| | - Alessandro Franchi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Syed Ali Khurram
- Unit of Oral and Maxillofacial Pathology, School of Clinical Dentistry, 19 Claremont Crescent, Sheffield, S10 2TA, UK
| | - Philip Da Forno
- Department of Cellular Pathology, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Juliana Robledo
- Department of Pathology and Laboratory Medicine, Long School of Medicine, UT Health, San Antonio, TX, USA
| | - John R Kalmar
- Division of Oral and Maxillofacial Pathology, The Ohio State University College of Dentistry, Columbus, OH, USA
| | - Sarah Aguirre
- Division of Oral and Maxillofacial Pathology, The University of Tennessee Health Science Center College of Dentistry, Memphis, TN, USA
| | - Jeffrey F Krane
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - Jose Luis Tapia
- Department of Oral Diagnostic Sciences, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA
| | - Katalin Kiss
- Department of Pathology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kitrina Cordell
- Department of Diagnostic Sciences, Louisiana State University Health Sciences Center School of Dentistry, New Orleans, LA, USA
| | - Molly Rosebush
- Department of Diagnostic Sciences, Louisiana State University Health Sciences Center School of Dentistry, New Orleans, LA, USA
| | - A William Barrett
- Department of Histopathology, Queen Victoria Hospital, Holtye Road, East Grinstead, West Sussex, RH19 3DZ, UK
| | - Dolphine Oda
- Department Oral & Maxillofacial Surgery, School of Dentistry, University of Washington, Seattle, WA, USA
| | - Adel Assaad
- Department of Pathology, Virginia Mason Hospital & Seattle Medical Center, Seattle, WA, USA
| | - Toshitaka Nagao
- Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan
| | - Fumi Kawakami
- Department of Diagnostic Pathology, Kumamoto University Hospital, Kumamoto, Japan
| | - Masato Nakaguro
- Departments of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Ismail Zahir
- Department of Pathology Mount Sinai Brooklyn, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Kristina Wakeman
- Department of Pathology and Laboratory Medicine, University of Louisville, Louisville, KY, USA
| | | | - Jacinthe Chenevert
- Pathology Department, L'Hôtel-Dieu de Québec, Centre Hospitalier Universitaire de Québec, Laval University, Quebec, Canada
| | - Yi-Ling Lin
- Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles, CA, USA
| | - William H Westra
- Department of Pathology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Jeffrey Gagan
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Lisa M Rooper
- Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD, USA
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Bishop JA, Gagan J, Krane JF, Jo VY. Low-grade Apocrine Intraductal Carcinoma: Expanding the Morphologic and Molecular Spectrum of an Enigmatic Salivary Gland Tumor. Head Neck Pathol 2020; 14:869-875. [PMID: 31989433 PMCID: PMC7669952 DOI: 10.1007/s12105-020-01128-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/09/2020] [Indexed: 12/12/2022]
Abstract
Intraductal carcinoma (IDC) is the current designation for a salivary gland neoplasm previously referred to as "low-grade salivary duct carcinoma" and "low-grade cribriform cystadenocarcinoma," among others. IDC is conceptually believed to be similar to ductal carcinoma in-situ of the breast. Although IDC is one entity in the current WHO Classification of Head and Neck Tumors, recent studies have suggested that at least three subtypes exist: a low-grade, intercalated duct-like variant with frequent RET rearrangements; a high-grade apocrine variant with complex, salivary duct carcinoma-like genetics; and a mixed variant. We sought to characterize an unusual form of low-grade, purely apocrine IDC. Three cases of apocrine-type IDC with low-grade histology were retrieved from the authors' consultation files. Immunohistochemistry for androgen receptor, GCDFP-15, S100, smooth muscle actin, and p40 was performed. A custom, targeted next generation sequencing (NGS) panel including 1425 cancer-related genes was also done on all cases. All three cases developed in the parotid glands of men, aged 51, 63, and 73 years (mean, 62 years). All cases consisted of large, rounded macrocysts surrounded by smaller nests which were lined by cells with abundant granular eosinophilic cytoplasm and large round nuclei with prominent nucleoli. Pleomorphism was mild, the mitotic rate was low, and necrosis was absent. No cases had any invasive foci or areas of intercalated duct-like morphology. By immunohistochemistry, all cases were diffusely positive for androgen receptor and GCDFP-15, surrounded entirely by an intact layer of small myoepithelial cells positive for S100, smooth muscle actin, and p40. Targeted NGS results were obtained from two cases: both harbored HRAS mutations and copy number losses in TP53, while one case each harbored mutations in PIK3CA, SPEN, and ATM. Fusions were absent in both cases. All three patients were treated by surgery alone, and are currently free of disease (follow up 12-190 months). This study confirms the existence of a low-grade, purely apocrine form of IDC. In its pure form, i.e., without an intercalated duct-type component, low-grade apocrine IDC is genetically similar to high-grade salivary duct carcinoma, with frequent HRAS and PI3K pathway mutations. Despite its molecular similarities to the aggressive salivary duct carcinoma, low-grade apocrine IDC appears to behave in a very indolent manner, supporting is classification as a non-invasive neoplasm, and underscoring the need to distinguish these tumors from each other.
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Affiliation(s)
- Justin A Bishop
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Jeffrey Gagan
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jeffrey F Krane
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California At Los Angeles, Los Angeles, CA, USA
| | - Vickie Y Jo
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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Gottlieb JB, Joachim M, Leiser Y, Abdelraziq M, Abu El-Naaj I. Polymorphous Low-Grade Adenocarcinoma: A Proposed Reconstruction Protocol Based on Past Surgical Experience. J Craniofac Surg 2019; 30:1228-1230. [PMID: 30817510 DOI: 10.1097/scs.0000000000005328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To propose a reconstructive protocol based on surgical management experience of polymorphous low-grade adenocarcinoma (PLGA) and the location of the primary lesion. METHODS Data on the surgical management and the reconstructive technique of 14 histologically conformed patients with PLGA, all treated by the same surgeon, were analyzed and evaluated. RESULTS Mean follow-up period in our series was 6.2 years. Mean age at diagnosis was 55.5 years and female to male ratio was 2.2:1. The most common presenting sign was a nonpainful lump or mass in an intraoral location. Most patients were managed by wide local excision and reconstruction method varied from primary closure to the use of radial forearm graft. Recurrence appeared in one of the patients in this series, while 2 required further radiation therapy. A protocol for reconstruction of intraoral patients with PLGA is suggested based on our analysis. CONCLUSION Surgical management is the gold standard for PLGA treatment. Neck dissection is recommended only in patients with presurgery fine-needle aspiration confirmed lymph node involvement. The reconstruction depends mainly on location and size of the primary lesion.
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Affiliation(s)
- Jonathan B Gottlieb
- Department of Oral and Maxillofacial Surgery, Baruch Padeh Medical Center, Poriya
| | - Michael Joachim
- Department of Oral and Maxillofacial Surgery, Baruch Padeh Medical Center, Poriya
| | - Yoav Leiser
- Department of Oral and Maxillofacial Surgery, Rambam Health Care Campus, Haifa
| | - Murad Abdelraziq
- Department of Oral and Maxillofacial Surgery, Baruch Padeh Medical Center, Poriya
| | - Imad Abu El-Naaj
- Department of Oral and Maxillofacial Surgery, Baruch Padeh Medical Center, Poriya.,Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
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The Role of Molecular Testing in the Differential Diagnosis of Salivary Gland Carcinomas. Am J Surg Pathol 2019; 42:e11-e27. [PMID: 29076877 DOI: 10.1097/pas.0000000000000980] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Salivary gland neoplasms are a morphologically heterogenous group of lesions that are often diagnostically challenging. In recent years, considerable progress in salivary gland taxonomy has been reached by the discovery of tumor type-specific fusion oncogenes generated by chromosome translocations. This review describes the clinicopathologic features of a selected group of salivary gland carcinomas with a focus on their distinctive genomic characteristics. Mammary analog secretory carcinoma is a recently described entity characterized by a t(12;15)(p13;q25) translocation resulting in an ETV6-NTRK3 fusion. Hyalinizing clear cell carcinoma is a low-grade tumor with infrequent nodal and distant metastasis, recently shown to harbor an EWSR1-ATF1 gene fusion. The CRTC1-MAML2 fusion gene resulting from a t(11;19)(q21;p13) translocation, is now known to be a feature of both low-grade and high-grade mucoepidermoid carcinomas associated with improved survival. A t(6;9)(q22-23;p23-34) translocation resulting in a MYB-NFIB gene fusion has been identified in the majority of adenoid cystic carcinomas. Polymorphous (low-grade) adenocarcinoma and cribriform adenocarcinoma of (minor) salivary gland origin are related entities with partly differing clinicopathologic and genomic profiles; they are the subject of an ongoing taxonomic debate. Polymorphous (low-grade) adenocarcinomas are characterized by hot spot point E710D mutations in the PRKD1 gene, whereas cribriform adenocarcinoma of (minor) salivary glands origin are characterized by translocations involving the PRKD1-3 genes. Salivary duct carcinoma (SDC) is a high-grade adenocarcinoma with morphologic and molecular features akin to invasive ductal carcinoma of the breast, including HER2 gene amplification, mutations of TP53, PIK3CA, and HRAS and loss or mutation of PTEN. Notably, a recurrent NCOA4-RET fusion has also been found in SDC. A subset of SDC with apocrine morphology is associated with overexpression of androgen receptors. As these genetic aberrations are recurrent they serve as powerful diagnostic tools in salivary gland tumor diagnosis, and therefore also in refinement of salivary gland cancer classification. Moreover, they are promising as prognostic biomarkers and targets of therapy.
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Said-Al-Naief N, Carlos R, Vance GH, Miller C, Edwards PC. Combined DOG1 and Mammaglobin Immunohistochemistry Is Comparable to ETV6-breakapart Analysis for Differentiating Between Papillary Cystic Variants of Acinic Cell Carcinoma and Mammary Analogue Secretory Carcinoma. Int J Surg Pathol 2017; 25:127-140. [PMID: 27670353 DOI: 10.1177/1066896916670005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
BACKGROUND We investigated the reliability of combined DOG1 and mammaglobin immunohistochemistry compared with ETV6 fluorescence in situ hybridization (FISH) in the assessment of salivary tumors previously diagnosed as acinic cell carcinoma (ACC). Ultrastructural features of cases reclassified as mammary analogue secretory carcinoma (MASC) were assessed by transmission electron microscopy (TEM). METHODS Immunohistochemical (IHC) reactivity to DOG1 and mammaglobin was validated against FISH targeting the ETV6 gene in all 14 cases. RESULTS Three cases with papillary cystic histomorphology previously diagnosed as ACC were revised to MASC. TEM features of the ETV6 rearrangement-positive MASC cases showed large numbers of secretory granules with extrusion into the intercellular spaces, well-developed endoplasmic reticulum, lipid-laden vacuoles, well-formed microvilli, and large lining cystic spaces. CONCLUSIONS Combined DOG1 and mammaglobin immunohistochemistry is comparable to ETV6 -breakapart analysis for differentiating between papillary cystic variants of ACC and MASC.
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Affiliation(s)
| | - Roman Carlos
- 2 Centro Clínico de Cabeza y Cuello/Hospital Herrera Llerandi, Guatemala City, Guatemala
| | - Gail H Vance
- 3 Department of Medical and Molecular Genetics Indiana University School of Medicine Indianapolis, IN, USA
| | - Caroline Miller
- 4 Department of Anatomy and Cell Biology Indiana University School of Medicine Indianapolis, IN, USA
| | - Paul C Edwards
- 5 Department of Oral Pathology, Medicine and Radiology Indiana University School of DentistryIndianapolis, IN, USA
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Skalova A, Michal M, Simpson RH. Newly described salivary gland tumors. Mod Pathol 2017; 30:S27-S43. [PMID: 28060365 DOI: 10.1038/modpathol.2016.167] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 08/08/2016] [Accepted: 08/09/2016] [Indexed: 12/22/2022]
Abstract
This review concentrates on three salivary gland tumors that have been accepted in the recent literature as new neoplastic entities: mammary analog secretory carcinoma (MASC), sclerosing polycystic adenoma (SPA) and cribriform adenocarcinoma of tongue and other minor salivary glands (CAMSGs). MASC is a distinctive low-grade malignant salivary cancer that harbors a characteristic chromosomal translocation, t(12;15) (p13;q25) resulting in an ETV6-NTRK3 fusion. SPA is a rare lesion often mistaken histologically for low-grade salivary carcinoma. Previously thought to be a reactive fibroinflammatory process, but recent evidence of clonality, recurrences in up 30%, and dysplastic foci suggest it may be truly neoplastic. CAMSG is a distinct tumor entity that differs from polymorphous low-grade adenocarcinoma (PLGA) by location (ie, most often arising on the tongue), by prominent nuclear clearing, alterations of the PRKD gene family and clinical behavior with frequent metastases at the time of presentation of the primary tumor. Early metastatic disease seen in most cases of CAMSG associated with indolent behavior makes it a unique neoplasm among all low-grade salivary gland tumors. Salivary glands may give rise to a wide spectrum of different tumors. They are often diagnostically challenging as morphological features often overlap between different entities. Although conventional morphology in combination with immunohistochemical findings still provide the most important clues for diagnosis, recent advances in molecular pathology offer new diagnostic tools in investigating the differential diagnosis, as well as providing potentially valuable prognostic indicators. In the last two decades, several new salivary gland tumor entities have been described, namely MASC, SPA and CAMSGs.
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Affiliation(s)
- Alena Skalova
- Department of Pathology, Charles University, Faculty of Medicine in Plzen, Plzen, Czech Republic
| | - Michal Michal
- Department of Pathology, Charles University, Faculty of Medicine in Plzen, Plzen, Czech Republic
| | - Roderick Hw Simpson
- Department of Anatomical Pathology, Foothills Medical Centre, Calgary, Alberta, Canada
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Skalova A. Mammary analogue secretory carcinoma of salivary gland origin: an update and expanded morphologic and immunohistochemical spectrum of recently described entity. Head Neck Pathol 2013; 7 Suppl 1:S30-6. [PMID: 23821207 PMCID: PMC3712092 DOI: 10.1007/s12105-013-0455-y] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 06/08/2013] [Indexed: 12/01/2022]
Abstract
Mammary analogue secretory carcinoma of salivary gland origin (MASC) is a recently described tumor with ETV6 translocation. Akin to secretory breast cancer, MASC expresses S-100 protein, mammaglobin, vimentin, and harbors a t(12;15) (p13;q25) translocation which leads to ETV6-NTRK3 fusion product. Histologically, MASC displays a lobulated growth pattern and is often composed of microcystic, tubular, and solid structures with abundant eosinophilic homogeneous or bubbly secretions. Colloid-like secretory material stains positive for periodic acid-Schiff (PAS) with and without diastase and for Alcian blue. The cells of MASC are devoid of PAS-positive secretory zymogen granules. These features help to exclude the most important differential diagnostic considerations, namely acinic cell carcinoma, low-grade cribriform cystadenocarcinoma, cystadenocarcinoma (not otherwise specified), and low-grade mucoepidermoid carcinoma. To date the presence of the ETV6-NTRK3 fusion gene has not been demonstrated in any other salivary gland tumor than MASC. It is likely that MASC is more common than currently recognized and with further studies, the clinical need for molecular studies of the ETV6-NTRK3 fusion may diminish. However, molecular testing is recommended at this time to arrive at the diagnosis of MASC.
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Affiliation(s)
- Alena Skalova
- Sikl’s Department of Pathology, Faculty of Medicine in Pilsen, Faculty Hospital, Medical Faculty of Charles University, E. Benese 13, 305 99 Plzen, Czech Republic
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Bishop JA, Yonescu R, Batista D, Begum S, Eisele DW, Westra WH. Utility of mammaglobin immunohistochemistry as a proxy marker for the ETV6-NTRK3 translocation in the diagnosis of salivary mammary analogue secretory carcinoma. Hum Pathol 2013; 44:1982-8. [PMID: 23773480 DOI: 10.1016/j.humpath.2013.03.017] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/25/2013] [Accepted: 03/28/2013] [Indexed: 01/29/2023]
Abstract
Mammary analogue secretory carcinoma is a recently described salivary gland neoplasm defined by ETV6-NTRK3 gene fusion. Mammary analogue secretory carcinoma's morphology is not entirely specific and overlaps with other salivary gland tumors. Documenting ETV6 rearrangement is confirmatory, but most laboratories are not equipped to perform this test. As mammary analogue secretory carcinomas are positive for mammaglobin, immunohistochemistry could potentially replace molecular testing as a confirmatory test, but the specificity of mammaglobin has not been evaluated across a large and diverse group of salivary gland tumors. One hundred thirty-one salivary gland neoplasms were evaluated by routine microscopy, mammaglobin immunohistochemistry, and ETV6 break-apart fluorescent in situ hybridization. The cases included 15 mammary analogue secretory carcinomas, 44 adenoid cystic carcinomas, 33 pleomorphic adenomas, 18 mucoepidermoid carcinomas, 10 acinic cell carcinomas, 4 adenocarcinomas not otherwise specified, 3 polymorphous low-grade adenocarcinomas, 3 salivary duct carcinomas, and 1 low-grade cribriform cystadenocarcinoma. All 15 mammary analogue secretory carcinomas harbored the ETV6 translocation and were strongly mammaglobin positive. None of the 116 other tumors carried the ETV6 translocation; however, mammaglobin staining was present in 1 (100%) of 1 low-grade cribriform cystadenocarcinoma, 2 (67%) of 3 polymorphous low-grade adenocarcinomas, 2 (67%) of 3 salivary duct carcinomas, 2 (11%) of 18 mucoepidermoid carcinomas, and 2 (6%) of 33 pleomorphic adenomas. Mammaglobin is highly sensitive for mammary analogue secretory carcinoma, but immunostaining can occur in a variety of tumors that do not harbor the ETV6 translocation. Strategic use of mammaglobin immunostaining has a role in the differential diagnosis of salivary gland neoplasms, but it should not be indiscriminately used as a confirmatory test for mammary analogue secretory carcinoma.
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Affiliation(s)
- Justin A Bishop
- Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD 21231.
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