-
Head and Neck Pathology Mar 2023Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the... (Review)
Review
BACKGROUND
Myoepithelial neoplasms of the salivary gland are benign or malignant neoplasms composed exclusively of neoplastic myoepithelial cells. These tumors, including the benign myoepithelioma and the malignant counterpart myoepithelial carcinoma, exhibit a wide range of cytomorphologic features and architectural patterns.
METHODS
Review.
RESULTS
Myoepithelial cells can be epithelial, plasmacytoid, clear cell, spindle cell, and/or oncocytic cell, arranging as trabeculae, solid sheets, nests, cords, and/or single cells. A stromal component is commonly but not universally present, Therefore, their differential diagnoses are quite broad, including salivary gland neoplasms especially those with a myoepithelial component, plasmacytoma, melanoma, and various mesenchymal tumors.
CONCLUSION
In this review, we summarize the characteristic histologic features, useful immunohistochemical panel, and common molecular alterations of myoepithelial tumors and their top differential diagnoses. A logical stepwise algorithmic approach and an immunohistochemical panel to include multiple myoepithelial markers are essential to establish the correct diagnosis.
Topics: Humans; Biomarkers, Tumor; Immunohistochemistry; Salivary Gland Neoplasms; Salivary Glands; Myoepithelioma; Carcinoma
PubMed: 36928733
DOI: 10.1007/s12105-022-01502-0 -
Annales de Pathologie Nov 2023Myoepithelial neoplasms of soft tissue represent a rare entity which has been described only recently when compared to salivary gland tumors with whom they share...
Myoepithelial neoplasms of soft tissue represent a rare entity which has been described only recently when compared to salivary gland tumors with whom they share histopathological and molecular features. The most common locations are the superficial soft tissues of the limbs and limb girdles. However, they can rarely occur in the mediastinum, abdomen, bone, skin and visceral organs. Benign forms (myoepithelioma and mixed tumor) are more frequent than myoepithelial carcinoma and the latter mostly affects children and young adults. Diagnosis is mainly based on histology, which shows a proliferation of myoepithelial cells of variable morphology with or without glandular structures in a myxoid background, and immunohistochemistry, which shows co-expression of epithelial and myoepithelial markers. Molecular tests are not mandatory, but in selected cases FISH analysis can prove useful as about 50% of myoepitheliomas show EWSR1 (or rarely FUS) rearrangements and mixed tumors show PLAG1 rearrangements. Here, we present a case of a mixed tumor of the soft tissue occuring in the hand with expression of PLAG1 in immunohistochemistry.
Topics: Humans; Adenoma, Pleomorphic; Biomarkers, Tumor; Immunohistochemistry; Myoepithelioma; Salivary Gland Neoplasms; Soft Tissue Neoplasms
PubMed: 36906453
DOI: 10.1016/j.annpat.2023.02.008 -
Surgical Neurology International 2023Myoepithelial tumors have been widely described as a rare form of salivary gland neoplasm, although currently soft-tissue phenotypes have also been identified. These are...
BACKGROUND
Myoepithelial tumors have been widely described as a rare form of salivary gland neoplasm, although currently soft-tissue phenotypes have also been identified. These are tumors composed entirely of myoepithelial cells that exhibit a dual epithelial and smooth muscle phenotype. The occurrence of myoepithelial tumors within the central nervous system is also extremely rare, with only a few cases reported. Treatment options include surgical resection, chemotherapy, radiotherapy, or a combination of these approaches.
CASE DESCRIPTION
The authors present a case of soft-tissue myoepithelial carcinoma with an unusual brain metastasis, rarely described in the literature. The purpose of this article is to present an update on the diagnosis and treatment of this pathology when affecting the central nervous system, through the review of the current evidence.
CONCLUSION
However, despite complete surgical resection, there is about a significative high rate of local recurrence and metastasis. Careful patient follow-up and staging is essential for better characterization and understanding of this tumor's behavior.
PubMed: 36895250
DOI: 10.25259/SNI_55_2023 -
Diagnostic Cytopathology Jun 2023Myoepitheliomas are rare tumours of salivary glands. Mucinous myoepithelioma (MM) is a newly described variant with rare cases reported in the literature. This case...
Myoepitheliomas are rare tumours of salivary glands. Mucinous myoepithelioma (MM) is a newly described variant with rare cases reported in the literature. This case report highlights cytopathologic features with histologic follow up of MM.
Topics: Humans; Myoepithelioma; Biopsy, Fine-Needle; Parotid Neoplasms; Follow-Up Studies; Parotid Gland
PubMed: 36880217
DOI: 10.1002/dc.25121 -
Journal of Cutaneous Pathology May 2023Cutaneous syncytial myoepithelioma is a tumor type that was initially reported in 2013 as a syncytial variant of cutaneous myoepithelioma characterized by intradermal... (Review)
Review
Cutaneous syncytial myoepithelioma is a tumor type that was initially reported in 2013 as a syncytial variant of cutaneous myoepithelioma characterized by intradermal nodular proliferation of oval to spindle-shaped tumor cells in solid and syncytial patterns. Fusion of genes Ewing sarcoma breakpoint region 1 / EWS RNA binding protein 1 (EWSR1) and pre-B cell leukemia homeobox 3 (PBX3) is found in approximately 90% of the cases. We report a case of cutaneous syncytial myoepithelioma with diagnostic difficulty due to folliculocentric morphology and atypical immunohistochemical results, including diffuse positivity of α-smooth muscle actin and claudin 4 and negative immunoreactions for epithelial membrane antigen and S100 protein. In the present case, fluorescence in situ hybridization study demonstrated EWSR1 rearrangement. We further provide a discussion of differential diagnoses with a review of relevant literature.
Topics: Humans; Biomarkers, Tumor; Gene Rearrangement; In Situ Hybridization, Fluorescence; Myoepithelioma; RNA-Binding Protein EWS; S100 Proteins; Skin Neoplasms
PubMed: 36820993
DOI: 10.1111/cup.14419 -
Journal of Stomatology, Oral and... Sep 2023Myoepithelioma is an infrequent benign tumor of the salivary glands, characterized by its composition of myoepithelial cells which can show different shapes and be...
Myoepithelioma is an infrequent benign tumor of the salivary glands, characterized by its composition of myoepithelial cells which can show different shapes and be arranged in various patterns with a well-circumscribed or encapsulated growth. This tumor commonly presents in adults as an asymptomatic swelling of the parotid gland, very rarely in minor salivary glands of children or adolescents, and even rarer in the buccal mucosa, with only six cases reported to date and only one of them presented in an adolescent. We present an additional case of myoepithelioma in the buccal mucosa of a 16-year-old male, with a novel clinical presentation as a non-submucosal exophytic mass. Immunohistochemically, neoplastic cells were positive for CK, S100, p63, and GFAP. The tumour was treated surgically, and the patient showed satisfactory evolution at 1 year of follow-up. The clinical and histopathological characteristics of the reported cases are discussed.
Topics: Male; Adult; Child; Humans; Adolescent; Salivary Gland Neoplasms; Myoepithelioma
PubMed: 36758900
DOI: 10.1016/j.jormas.2023.101419 -
Histopathology May 2023Extraskeletal myxoid chondrosarcoma (EMC) is a rare form of adult sarcoma with distinct histology and NR4A3 gene fusion. Immunohistochemically, EMCs are variably...
AIMS
Extraskeletal myxoid chondrosarcoma (EMC) is a rare form of adult sarcoma with distinct histology and NR4A3 gene fusion. Immunohistochemically, EMCs are variably positive for S100 protein and neuroendocrine markers. Unlike histologically similar soft-tissue myoepithelial tumours, keratin expression is rare. Prompted by two recent EMC cases with diffuse keratin expression, we investigated the expression of epithelial markers in a molecularly confirmed cohort of EMC and identified two additional similar cases.
METHODS AND RESULTS
Four keratin-positive EMCs occurred in one man and three women aged 46-59 years. All tumours displayed nonclassic histology with prominent stromal fibrosis, and keratin AE1/AE3 was expressed either diffusely (N = 2) or focally (N = 2). In one tumour, keratin expression was limited to the sclerotic area. All tumours coexpressed epithelial membrane antigen and two additionally expressed S100 protein or glial fibrillary acidic protein. All tumours harboured NR4A3 fusions, including TAF15::NR4A3 (N = 1) and EWSR1::NR4A3 (N = 3). Two cases were initially considered as most consistent with myoepithelial tumours based on widespread stromal fibrosis and keratin expression. DNA methylation analysis classified two tumours tested as EMCs.
CONCLUSIONS
We identified a small subset of EMCs characterised by keratin expression and prominent stromal fibrosis. This histological pattern must be recognised in the differential diagnosis of myoepithelial tumours because misclassification may lead to the erroneous prediction of tumour behaviour and may alter patient management. NR4A3 genetic analysis should be considered even in the face of keratin expression and prominent stromal fibrosis.
Topics: Adult; Male; Humans; Female; Myoepithelioma; Keratins; Calmodulin-Binding Proteins; RNA-Binding Proteins; Chondrosarcoma; Soft Tissue Neoplasms; S100 Proteins; Fibrosis
PubMed: 36754860
DOI: 10.1111/his.14882 -
Head and Neck Pathology Jun 2023Secretory myoepithelial carcinomas (SMCA) are rare, mucinous, signet ring predominant tumors with primitive myoepithelial features. While many mucinous salivary gland...
BACKGROUND
Secretory myoepithelial carcinomas (SMCA) are rare, mucinous, signet ring predominant tumors with primitive myoepithelial features. While many mucinous salivary gland tumors have now been molecularly characterized, key drivers in SMCA have yet to be elucidated. Recently, NKX3.1, a homeodomain transcription factor implicated in salivary mucous acinar development was also shown in a subset of salivary mucinous neoplasms, salivary intraductal papillary mucinous neoplasms (SG-IPMN). To date, NKX3.1 expression has not been characterized in other mucinous salivary lesions. Here, we report molecular and extended immunophenotypic findings in SMCA and NKX3.1 expression in the context of other head and neck lesions.
METHODS
We retrieved 4 previously reported SMCA, performed additional immunohistochemical and targeted next-generation sequencing (NGS). We also investigated the use of NKX3.1 as a marker for SMCA in the context of its prevalence and extent (using H-score) in a mixed cohort of retrospectively and prospectively tested head and neck lesions (n = 223) and non-neoplastic tissues (n = 66).
RESULTS
NKX3.1 positivity was confirmed in normal mucous acini as well as in mucous acinar class of lesions (5/6, mean H-score: 136.7), including mucinous adenocarcinomas (3/4), SG-IPMN (1/1), and microsecretory adenocarcinoma (MSA) (1/1). All SMCA were positive. Fluorescence in situ hybridization for SS18 rearrangements were negative in all successfully tested cases (0/3). NGS was successful in two cases (cases 3 and 4). Case 3 demonstrated a PTEN c.655C>T p.Q219* mutation and a SEC16A::NOTCH1 fusion while case 4 (clinically aggressive) showed a PTEN c.1026+1G>A p.K342 splice site variant, aTP53 c.524G>A p.R175H mutation and a higher tumor mutation burden (29 per Mb). PTEN immunohistochemical loss was confirmed in both cases and a subset of tumor cells showed strong (extreme) staining for P53 in Case 4.
CONCLUSION
Despite a partial myoepithelial phenotype, SMCA, along with mucinous adenocarcinomas/SG-IPMN and MSA, provisionally constitute a mucous acinar class of tumors based on morphology and NKX3.1 expression. Like salivary mucinous adenocarcinomas/SG-IPMN, SMCA also show alterations of the PTEN/PI3K/AKT pathway and may show progressive molecular alterations. We document the first extramammary tumor with a SEC16A::NOTCH1 fusion.
Topics: Humans; Adenocarcinoma; Adenocarcinoma, Mucinous; Biomarkers, Tumor; Endoplasmic Reticulum; Golgi Apparatus; In Situ Hybridization, Fluorescence; Myoepithelioma; Pancreatic Intraductal Neoplasms; Phenotype; Phosphatidylinositol 3-Kinases; Retrospective Studies; Salivary Gland Neoplasms; Transcription Factors; Vesicular Transport Proteins
PubMed: 36746884
DOI: 10.1007/s12105-023-01524-2 -
Oral Surgery, Oral Medicine, Oral... Mar 2023An ectomesenchymal chondromyxoid tumor (ECT) is an uncommon soft tissue tumor with an enigmatic histogenesis and striking predilection for the tongue. We present 5 new... (Review)
Review
OBJECTIVE
An ectomesenchymal chondromyxoid tumor (ECT) is an uncommon soft tissue tumor with an enigmatic histogenesis and striking predilection for the tongue. We present 5 new cases and review the literature.
STUDY DESIGN
We performed a retrospective search for ECTs within the University of Kentucky Oral Pathology Biopsy Service and the published literature.
RESULTS
Five new cases from the biopsy archives and 103 well-documented ECT cases from the literature were compiled and reviewed. Whereas 89.8% of ECT are found on the anterior/dorsal/lateral/unspecified tongue, 4.6% are on the posterior/base of tongue. Six extralingual cases are reported. The age ranges from 2.3 to 78 years with an average of 40. Most ECT react with GFAP (92.8%) and S-100 protein (91.3%). Whereas 21/23 cases demonstrated a RREB1-MKL2 fusion, EWSR1 gene mutations are identified in 4 cases.
CONCLUSIONS
Most ECT are readily diagnosed on routine histopathology in combination with tumor site, immunohistochemical findings, and molecular findings; however, a subset share overlapping features with myoepithelioma of soft parts. As further molecular analysis is performed on this tumor, we may find that a subset of previously diagnosed ECT relate to or represent myoepithelioma or conversely fall under the spectrum of the pluripotent ECT.
Topics: Humans; Child, Preschool; Child; Adolescent; Young Adult; Adult; Middle Aged; Aged; Myoepithelioma; Tongue Neoplasms; Retrospective Studies; Soft Tissue Neoplasms; Tongue
PubMed: 36739213
DOI: 10.1016/j.oooo.2022.12.004 -
The American Journal of Surgical... Apr 2023Glioma-associated oncogene 1 ( GLI1 ) alterations have been described in pericytoma with t(7;12), gastroblastoma, plexiform fibromyxoma, and an emerging class of GLI1...
Glioma-associated oncogene 1 ( GLI1 ) alterations have been described in pericytoma with t(7;12), gastroblastoma, plexiform fibromyxoma, and an emerging class of GLI1 -rearranged or amplified mesenchymal neoplasms including "nested glomoid neoplasm". The immunophenotype of these tumor types is nonspecific, making some cases difficult to diagnose without sequencing. The utility of GLI1 immunohistochemistry (IHC) in distinguishing nested glomoid neoplasms and pericytomas with t(7;12) from morphologic mimics is unknown. To investigate the diagnostic value of GLI1 IHC, we determined its sensitivity and specificity in a "test cohort" of 23 mesenchymal neoplasms characterized by GLI1 alterations, including 12 nested glomoid neoplasms (7 GLI1 -rearranged, 4 GLI1 amplified, and 1 unknown GLI1 status), 9 pericytomas with t(7;12), 1 gastroblastoma, and 1 malignant epithelioid neoplasm with PTCH1 :: GLI1 fusion. GLI1 IHC was 91.3% sensitive in this cohort; all tumors except 2 pericytomas with t(7;12) expressed GLI1. GLI1 was also expressed in 1 of 8 (12%) plexiform fibromyxomas. Nineteen of 22 GLI1-positive tumors showed nuclear and cytoplasmic staining, while 3 showed nuclear staining only. GLI1 IHC was 98.0% specific; among morphologic mimics [40 well-differentiated neuroendocrine tumors, 10 atypical lung carcinoids, 20 paragangliomas, 20 glomus tumors, 20 solitary fibrous tumors, 10 Ewing sarcomas, 10 alveolar rhabdomyosarcomas (ARMS), 10 BCOR -altered sarcomas, 10 myoepitheliomas, 9 myopericytomas, 9 epithelioid schwannomas, 9 ossifying fibromyxoid tumors, 10 biphasic synovial sarcomas, 10 PEComas, 31 gastrointestinal stromal tumors, 10 inflammatory fibroid polyps, 11 pseudoendocrine sarcomas], 5 of 249 tumors expressed GLI1 (2 well-differentiated neuroendocrine tumors, 1 ARMS, 1 Ewing sarcoma, 1 BCOR -altered sarcoma). GLI1 IHC was also performed on a separate cohort of 13 molecularly characterized mesenchymal neoplasms in which GLI1 copy number gain was identified as a putatively secondary event by DNA sequencing (5 dedifferentiated liposarcoma [DDLPS], 2 adenosarcomas, 2 unclassified uterine sarcomas, 1 leiomyosarcoma, 1 ARMS, 1 intimal sarcoma, 1 osteosarcoma); 2 DDLPS, 1 ARMS, and 1 unclassified uterine sarcoma expressed GLI1. Lastly, because pleomorphic sarcomas sometimes show GLI1 amplification or copy number gain, GLI1 IHC was performed on a separate "pleomorphic sarcoma" cohort: GLI1 was expressed in 1 of 27 DDLPS, 1 of 9 leiomyosarcomas, and 2 of 10 pleomorphic liposarcomas, and it was negative in 23 well-differentiated liposarcomas and 9 unclassified pleomorphic sarcomas. Overall, GLI1 IHC was 91.3% sensitive and 98.0% specific for mesenchymal tumor types with driver GLI1 alterations among morphologic mimics. GLI1 expression was less frequent in other tumor types with GLI1 copy number gain. Given its specificity, in the appropriate morphologic context, GLI1 IHC may be a useful diagnostic adjunct for mesenchymal neoplasms with GLI1 alterations.
Topics: Humans; Immunohistochemistry; Zinc Finger Protein GLI1; Sarcoma, Ewing; Sarcoma; Liposarcoma; Soft Tissue Neoplasms; Neuroendocrine Tumors; Biomarkers, Tumor
PubMed: 36693363
DOI: 10.1097/PAS.0000000000002018