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International Journal of Surgery Case... Jul 2024Tumours of salivary glands are rare and have various histo-pathological subtypes. Myoepitheliomas were first classified by Sheldon et al. and the criterion to classify...
INTRODUCTION
Tumours of salivary glands are rare and have various histo-pathological subtypes. Myoepitheliomas were first classified by Sheldon et al. and the criterion to classify or diagnose it was first defined by Barnes et al. and Sciubba and Brannon. Myoepithelioma accounts for less than 1 % of all salivary gland tumours, 40 % of these tumours occur in the parotid gland while 21 % occur in the minor salivary glands. A case of myoepithelioma of a minor salivary gland of the cheek is described, emphasizing the problems of the differential diagnosis.
PRESENTATION OF THE CASE
A 40-year-old female reported to the department with a complaint of a cheek bite on her right side for a few months. The physical examination showed a presence of lobulated whitish mucosa on the right buccal mucosa at the level of the occlusal plane, on palpation it revealed a non-painful mass approximately 1.5 cm in radius, mobile to bimanual palpation. An excisional biopsy was performed under local anaesthesia. Microscopic and immunohistochemistry confirmed the tumour to be a myoepithelioma of a minor salivary gland with the absence of definitive features of malignancy.
DISCUSSION
Due to their infrequency and multiplicity of histopathology, myoepitheliomas present difficulties in diagnosis. Cellular varieties can be misdiagnosed as malignancies. A key to determining diagnostic criteria for myoepitheliomas is to study cellular morphology, cytoplasmic filament expression, and ultrastructural features of the tumour and apply this information to defining myoepitheliomas.
CONCLUSION
Myoepitheliomas are rare tumours, utilization of immunohistochemical staining and electron microscopy are useful tools for the diagnosis of myoepitheliomas to ensure proper treatment and follow-up.
PubMed: 38875824
DOI: 10.1016/j.ijscr.2024.109849 -
Pathology May 2024
PubMed: 38816310
DOI: 10.1016/j.pathol.2024.03.002 -
Animals : An Open Access Journal From... May 2024Compared to the number of studies on the neoplasms of laboratory rodents, fewer studies have focused on spontaneous neoplasms in pet rodents. Notably, the mouse mammary...
Compared to the number of studies on the neoplasms of laboratory rodents, fewer studies have focused on spontaneous neoplasms in pet rodents. Notably, the mouse mammary tumor virus (MMTV) is associated with mammary tumors in rodents. In this study, 77 tumors and tumor-like lesions of biopsy samples were collected from 70 pet rodents, including hamsters (n = 47), guinea pigs (n = 16), unknown species (n = 4), rats (n = 2), and a gerbil. Fifty tumors were collected from 47 hamsters, in which the most common tumors were mammary tumors (13/50), followed by fibrosarcoma (9/50), mast cell tumors (4/50), and squamous cell carcinoma (4/50). The collected subtypes of mammary tumors in hamsters included tubular carcinoma (n = 5), tubular adenoma (n = 4), carcinoma and malignant myoepithelioma (n = 1), simple tubular carcinoma (n = 1), adenosquamous carcinoma (n = 1), and tubulopapillary adenoma (n = 1). In addition, twenty tumors were collected from guinea pigs, in which the most common tumor was lipoma (6/20), followed by adenocarcinoma of the mammary gland (4/20), trichofolliculoma (2/20), and collagenous hamartomas (2/20). In guinea pigs, the subtypes of mammary gland tumors were tubular carcinoma (n = 2), tubular and solid carcinoma (n = 1), and tubulopapillary carcinoma (n = 1). In 20 cases of mammary tumors, MMTV was not detected, implicating no evidence of MMTV infection in mammary oncogenesis in pet rodents in Taiwan.
PubMed: 38791685
DOI: 10.3390/ani14101469 -
Human Pathology May 2024Myoepithelial tumors of the soft tissue and bone occurring in patients 21 years of age and younger are rare, and their clinicopathologic features remain incompletely...
Myoepithelial tumors of the soft tissue and bone occurring in patients 21 years of age and younger are rare, and their clinicopathologic features remain incompletely understood. We studied a well-characterized series of 40 such tumors. Cases were retrieved from our archives for the period 2009-2022 and re-reviewed. Available immunohistochemical and molecular genetic data was collected. Clinical information including available follow-up was obtained. The tumors occurred in 18 males and 22 females, ranging from 3 months to 21 years of age (median 11.5 years), and involved a wide variety of soft tissue (n = 36) and bone (n = 4) locations. Histologically benign myoepithelial tumors tended to occur in adolescents (median age 14.5 years; range 5-21 years), whereas myoepithelial carcinomas occurred in younger patients (median age 8.5 years; range 3 months-20 years). Microscopically, the tumors showed a complex admixture of epithelioid, plasmacytoid and spindled cells in a variably hyalinized, myxoid, chondroid or chondromyxoid background. Small subsets of histologically malignant tumors had rhabdoid or "round cell" features. Immunohistochemistry showed 35/40 (88%) cases to be positive with at least one keratin antibody. The 5 keratin-negative tumors were uniformly positive for S100 protein and/or SOX10 and expressed EMA (4 cases) and/or p63 (3 cases). EMA, SMA and GFAP were positive in 21/25 (84%), 13/21 (62%), and 8/21 (38%) tumors, respectively. SMARCB1 and SMARCA4 expression was retained in 29/31 (94%) and 22/22 (100%) of cases, respectively. FISH for EWSR1 gene rearrangement was positive in 6/18 (33%) tested cases. Two EWSR1-negative tumors were also FUS-negative. NGS identified EWSR1::POU5F1, FUS::KLF17, and BRD4::CITED1 gene fusions in 3 tested cases. Clinical follow-up (22 patients; median 23 months; range 1-119 months) showed 3 patients with local recurrences and 5 with distant metastases (lymph nodes, lung, and brain). Three patients died of disease, 3 were alive with recurrent or unresectable disease, and 16 were disease-free. Adverse clinical outcomes were seen only in patients with malignant tumors. We conclude that myoepithelial neoplasms of soft tissue and bone are over-repesented in patients ≤21 years of age, more often histologically malignant, and potentially lethal. Histologic evaluation appears to reliably predict the behavior of these rare tumors.
PubMed: 38782103
DOI: 10.1016/j.humpath.2024.05.007 -
Modern Pathology : An Official Journal... May 2024The EWSR1::PBX3 fusion gene, commonly associated with cutaneous syncytial myoepitheliomas, is also found in myoepithelial tumors (METs) of bone and soft tissue. These...
The EWSR1::PBX3 fusion gene, commonly associated with cutaneous syncytial myoepitheliomas, is also found in myoepithelial tumors (METs) of bone and soft tissue. These tumors typically demonstrate benign histology and favorable outcomes. This study examines 6 previously unreported intraosseous METs harboring the EWSR1::PBX3 fusion, focusing on their histopathologic characteristics, immunophenotype, clinical and radiographic profiles, and patient outcomes. The cohort comprised 5 men and 1 woman, aged 25 to 65 years (median age: 31 years), with tumors located in the proximal tibia (3 cases), distal radius (2 cases), and ilium (1 case) and sizes between 3.2 and 12.2 cm (median size: 3.9 cm). Imaging showed osteolytic lesions with varying degrees of cortical involvement and soft tissue extension in 3 cases. Histologically, 4 tumors showed mainly uniform oval-to-spindled cells in syncytial or fascicular arrangements within a collagenous matrix, displaying either bland nuclear features or mild atypia, and low to slightly elevated mitotic activity (≤1 per 10 high-power fields in 3 cases and 6 per 10 high-power fields in 1), classifying them as benign or atypical METs. In contrast, 2 tumors exhibited pronounced nuclear atypia with ovoid, spindled, epithelioid and round cells, hyperchromatic nuclei, inconspicuous nucleoli, increased N/C ratios, high mitotic rates (17 and 19 per 10 high-power fields), and extensive necrosis. Both tumors behaved aggressively-one patient underwent amputation after neoadjuvant chemotherapy and radiation, and the other died within 7 months with the disease still present. Immunohistochemically, the tumors consistently expressed epithelial membrane antigen and S100 but lacked keratin (AE1/AE3) expression. Our study demonstrated that bone METs with EWSR1::PBX3 fusions encompass a histologic continuum from benign to malignant, with benign/atypical METs mirroring their cutaneous analogs in morphology, and malignant variants distinguished by heterogeneous cytologic and architectural features, pronounced nuclear atypia, and high mitotic rates.
PubMed: 38763423
DOI: 10.1016/j.modpat.2024.100514 -
Genes, Chromosomes & Cancer May 2024We describe a case of a pleomorphic adenoma (PA) arising from the para-tracheal accessory salivary gland in a 44-year-old male harboring a novel WWTR1::NCOA2 gene...
We describe a case of a pleomorphic adenoma (PA) arising from the para-tracheal accessory salivary gland in a 44-year-old male harboring a novel WWTR1::NCOA2 gene fusion. To our knowledge, this novel gene fusion has not been described previously in salivary gland tumors. The patient presented with hoarseness of voice. The radiological exam revealed a mass in the upper third of the trachea involving the larynx. Histologically, the tumor consisted of bland-looking monocellular eosinophilic epithelial cells arranged in cords and sheets separated by thin fibrous stroma, focally forming a pseudo-tubular pattern. In immunohistochemistry, the tumor cells demonstrated positivity for CK7, PS100, SOX10, and HMGA2; and negativity for CK5/6, p40 p63, and PLAG1. In addition, the clustering analysis clearly demonstrates a clustering of tumors within the PA group. In addition to reporting this novel fusion in the PA spectrum, we discuss the relevant differential diagnoses and briefly review of NCOA2 and WWTR1 gene functions in normal and neoplastic contexts.
Topics: Humans; Male; Nuclear Receptor Coactivator 2; Adult; HMGA2 Protein; Trans-Activators; Transcriptional Coactivator with PDZ-Binding Motif Proteins; Salivary Gland Neoplasms; Intracellular Signaling Peptides and Proteins; Oncogene Proteins, Fusion; Myoepithelioma
PubMed: 38747338
DOI: 10.1002/gcc.23244 -
Virchows Archiv : An International... May 2024Myoepithelial neoplasms of the skin and soft tissue still represent a confusing and somewhat controversial field in pathology as it appears that this category includes...
Molecular analysis of apocrine mixed tumors and cutaneous myoepitheliomas: a comparative study confirming a continuous spectrum of one entity with near-ubiquitous PLAG1 and rare mutually exclusive HMGA2 gene rearrangements.
Myoepithelial neoplasms of the skin and soft tissue still represent a confusing and somewhat controversial field in pathology as it appears that this category includes several different entities. However, recent studies have suggested that both apocrine mixed tumors (AMT) and cutaneous myoepitheliomas (CM) harbor identical chromosomal rearrangements involving the PLAG1 gene and hence may represent a morphological spectrum. The aim of the present study was to share our institutional experience with these tumors and specifically focus on studying their immunohistochemical and molecular features to further assess their relatedness. Eleven cases of AMT and 7 cases of CM were collected and analyzed using immunohistochemistry (IHC), PLAG1 FISH, and Archer FusionPlex assay. There were 14 male and 4 female patients with ages ranging from 26 to 85 years (median 55.8 years, mean 58.5 years). AMTs were mainly located in the head and neck (n = 10), while CMs were mainly located in the acral sites (n = 5). PLAG1 IHC was diffusely strongly positive in 14/17 (82%) cases, whereas a single case of AMT diffusely expressed HMGA2. Both tumor groups showed PLAG1 gene fusions which were detected in 6/13 analyzable samples (AMT, n = 4 and CM, n = 2), and included TRPS1::PLAG1 (n = 3), NDRG1::PLAG1 (n = 1), CTNNB1::PLAG1 (n = 1) and a novel PXDNL::PLAG1 fusion (n = 1). The remaining 5 cases were negative, 5 were not analyzable and the single case positive for HMGA2 by IHC revealed a potential HMGA2 gene rearrangement. The cases were further studied by FISH, with 12/17 cases showing PLAG1 gene rearrangement (AMT, n = 8 and CM, n = 4). Altogether, 14/18 cases showed PLAG1 gene rearrangement by at least one of the methods. PLAG1 immunohistochemistry had a 92% specificity and sensitivity. Our study provided additional data to suggest that AMT and CM share overlapping morphological and immunohistochemical features as well as molecular background characterized by PLAG1 gene fusions and thus represent a morphological spectrum. In addition, we identified a novel PXDNL::PLAG1 fusion and suggested that rare cases may harbor HMGA2 gene alterations which seem to be mutually exclusive with PLAG1 gene fusions. The relatedness of these tumors to salivary gland myoepithelial neoplasms and distinctness from eccrine mixed tumors and other skin and soft tissue myoepithelial neoplasms with EWSR1/FUS fusions is discussed.
PubMed: 38736009
DOI: 10.1007/s00428-024-03811-x -
Zhonghua Bing Li Xue Za Zhi = Chinese... May 2024To investigate the clinical application of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) in bone and soft tissue tumors and to analyze the cases...
[Detection of EWSR1 gene rearrangement by fluorescence in situ hybridization in bone and soft tissue tumors: clinical application evaluation and atypical signal analysis].
To investigate the clinical application of EWSR1 gene rearrangement by fluorescence in situ hybridization (FISH) in bone and soft tissue tumors and to analyze the cases with atypical signal pattern. The cases detected for EWSR1 gene rearrangement by FISH in Beijing Jishuitan Hospital, Capital Medical University from 2014 to 2021 were collected, and the value of detecting EWSR1 gene rearrangement for diagnosing bone and soft tissue tumors was analyzed. The cases with atypical positive signals were further analyzed by next generation sequencing (NGS). FISH using EWSR1 break-apart probe kit was successfully performed in 97% (205/211) of cases, 6 cases failed. Four of the 6 failures were due to improper decalcification, 1 case due to signal overlap caused by thick slices, and 1 case due to signal amplification and disorder. EWSR1 gene rearrangements were positive in 122 cases (122/205, 59%), atypical positive signal in 8 cases (8/205, 4%), and negative in 75 cases (75/205, 37%). In cases testing positive, the percentage of positive cells ranged from 34% to 98%, with 120 cases (120/122, 98%) showing a positive cell percentage greater than 50%. Among the 205 successfully tested cases, 156 cases were histologically diagnosed as Ewing's sarcoma, of which 110 were positive (110/156, 71%), 7 were atypical positive (7/156, 4%), and 39 were negative (39/156, 25%). Nine cases were histologically diagnosed as clear cell sarcoma of soft tissue, of which 6 were positive (6/9), 1 was atypical positive (1/9), and 2 were negative (2/9). Five cases were histologically diagnosed as extraskeletal myxoid chondrosarcoma, of which 2 were positive (2/5) and 3 were negative (3/5). Three cases were histologically diagnosed as angiomatoid fibrous histiocytoma, of which 2 were positive (2/3) and 1 was negative (1/3). Two cases were histologically diagnosed as myoepithelioma of soft tissue, of which 1 was positive (1/2) and 1 was negative (1/2). One case was histologically diagnosed as olfactory neuroblastoma with a positive result. The 29 other tumor cases including osteosarcoma, synovial sarcoma, and malignant melanoma and others were all negative. Basing on histology as the standard for diagnosis and considering atypical positive cases as negative, comparing with the 29 cases of other tumors as control group, the sensitivity for diagnosing Ewing's sarcoma through the detection of EWSR1 gene rearrangement was 71%, and the specificity was 100%; the sensitivity for diagnosing clear cell sarcoma of soft tissue was 67%, and the specificity was 100%; the sensitivity for diagnosing extraskeletal myxoid chondrosarcoma was 40%, and the specificity was 100%; the sensitivity for diagnosing angiomatoid fibrous histiocytoma was 67%, and the specificity was 100%; the sensitivity for diagnosing myoepithelioma of soft tissue was 50%, and the specificity was 100%; the sensitivity for diagnosing olfactory neuroblastoma was 100%, and the specificity was 100%. Four of 8 cases with atypical positive signals analyzed by NGS showed EWSR1 rearrangement, including EWSR1::FLI1 in one case of Ewing sarcoma, EWSR1::NFATC2 in one case of EWSR1::NFATC2-rearranged sarcoma, EWSR1::ATF1 in one case of clear cell sarcoma of soft tissue and EWSR1::NR4A3 in one case of extraskeletal myxoid chondrosarcoma. Detection of EWSR1 rearrangement by FISH is of utmost significance in the diagnosis of bone and soft tissue tumors. Cases with atypical positive signals should be further scrutinized, correlating with their histomorphology and verifying by NGS if necessary.
Topics: Humans; RNA-Binding Protein EWS; Soft Tissue Neoplasms; In Situ Hybridization, Fluorescence; Bone Neoplasms; Gene Rearrangement; Histiocytoma, Malignant Fibrous; Sarcoma, Ewing
PubMed: 38678326
DOI: 10.3760/cma.j.cn112151-20231025-00308 -
Clinical Oncology (Royal College of... Jul 2024Epidemiological evidence on myoepithelial carcinoma is rare. This study aimed to investigate the effect of tumor primary site and treatment modality on survival in...
AIM
Epidemiological evidence on myoepithelial carcinoma is rare. This study aimed to investigate the effect of tumor primary site and treatment modality on survival in patients with head and neck myoepithelial carcinoma.
MATERIALS AND METHODS
Data on adult patients diagnosed with head and neck myoepithelial carcinoma between 2000 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Uni- and multivariable Cox proportional hazard models were utilized to evaluate the effects of different tumor primary sites and treatment modalities on overall survival (OS) and cancer-specific survival (CSS), and expressed as hazard ratio (HR) and 95% confidence interval (CI).
RESULTS
A total of 415 patients were enrolled. No significant differences in OS and CSS were found between different tumor primary sites (P > 0.05). Compared with partial excision, patients with total excision (HR = 1.65, 95%CI: 1.12-2.42) (partial or total removal of the organ in which the tumor is located and complete removal of the tumor) or no surgery (HR = 3.52, 95%CI: 2.05-6.03) had worse OS. Compared with surgery only, patients with radiotherapy only had poorer OS (HR = 4.69, 95%CI: 2.32-9.46) and CSS (HR = 6.72, 95%CI: 2.59-17.46), while no significant differences in OS (P = 0.120) and CSS (P = 0.847) were found among patients who received surgery combined with radiotherapy. In patients with AJCC III/IV, patients with radiotherapy only (HR = 4.51, 95%CI: 1.61-12.62) had poorer OS compared to those with surgery only, whereas patients who received surgery combined with radiotherapy had better OS (HR = 0.50, 95%CI: 0.29-0.89).
CONCLUSION
The tumor primary site may not affect the prognosis of patients with myoepithelial carcinoma, while the effect of treatment modality on prognosis is related to the primary site and stage of the tumor.
Topics: Humans; Male; Female; Myoepithelioma; Middle Aged; Head and Neck Neoplasms; Aged; Adult; SEER Program; Survival Rate; Combined Modality Therapy; Prognosis; Retrospective Studies
PubMed: 38664176
DOI: 10.1016/j.clon.2024.04.003 -
Cureus Mar 2024Myoepithelioma is an uncommon benign tumor of the orofacial region arising from the salivary glands. These tumors are composed of specifically myoepithelial cells...
Myoepithelioma is an uncommon benign tumor of the orofacial region arising from the salivary glands. These tumors are composed of specifically myoepithelial cells lacking ductal differentiation and were initially considered as a type of pleomorphic adenoma. Though they commonly arise from the parotid gland, there are a few cases that emerge from the minor salivary glands of the palate and oral cavity. Myoepitheliomas resemble many other tumors arising from the palate including pleomorphic adenoma. This report depicts a case of myoepithelioma of the minor salivary gland of the palate in a 23-year-old patient and the successful management of the lesion.
PubMed: 38629005
DOI: 10.7759/cureus.56305