Mucoepidermoid microcarcinoma in the context of parotid gland cyst.

Mucoepidermoid carcinoma is a type of salivary gland cancer that can develop in the context of a parotid gland cyst. This type of tumor is composed of mucous, epidermoid, and intercalated cells, and usually presents as a slow-growing and painless mass. A parotid gland cyst is a condition in which a fluid-filled sac forms in the parotid gland. The tumor can be masked as it develops within the parotid cyst. A 45-year-old female patient presented with a suspect of benign neoplasm of the major salivary gland. She underwent partial right parotidectomy, which upon pathological analysis confirmed the diagnosis of mucoepidermoid microcarcinoma associated with parotid gland cysts. The patient did well and continues under regular follow-up with no further treatment.

Molecular Aspects of Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of the Salivary Gland.

BACKGROUND: Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs. METHODS: We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma. RESULTS: Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis. CONCLUSIONS: Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

Number of positive lymph nodes affects oncologic outcomes in cN0 mucoepidermoid carcinoma of the major salivary gland.

The survival significance of the number of positive lymph nodes in salivary gland carcinoma remains unclear. Thus, the current study aimed to determine the effect of the number of positive lymph nodes on disease-specific survival (DSS) and overall survival (OS) in cN0 mucoepidermoid carcinoma (MEC) of the major salivary gland. Patients surgically treated for MEC of the major salivary gland between 1975 and 2019 were retrospectively enrolled from the surveillance, epidemiology, and end results database. The total population was randomly divided into training and test groups (1:1). Primary outcome variables were DSS and OS. Prognostic models were constructed based on the independent prognostic factors determined using univariate and multivariate Cox analyses in the training group and were validated in the test group using C-index. A total of 3317 patients (1624 men and 1693 women) with a mean age of 55 ± 20 years were included. The number of positive lymph nodes was an independent prognostic factor for both DSS and OS, but the effect began when at least two positive lymph nodes for DSS and three positive lymph nodes for OS were found. Predictive models for DSS and OS in the training group had C-indexes of 0.873 (95% confidence interval [CI] 0.853-0.893) and 0.835 (95% CI 0.817-0.853), respectively. The validation of the test group showed C-indexes of 0.877 (95% CI 0.851-0.902) for DSS and 0.820 (95% CI 0.798-0.842) for OS. The number of positive lymph nodes was statistically associated with survival in cN0 major salivary gland MEC. The current prognostic model could provide individualized follow-up strategies for patients with high reliability.

Machine learning-based survival prediction nomogram for postoperative parotid mucoepidermoid carcinoma.

Parotid mucoepidermoid carcinoma (P-MEC) is a significant histopathological subtype of salivary gland cancer with inherent heterogeneity and complexity. Existing clinical models inadequately offer personalized treatment options for patients. In response, we assessed the efficacy of four machine learning algorithms vis-à-vis traditional analysis in forecasting the overall survival (OS) of P-MEC patients. Using the SEER database, we analyzed data from 882 postoperative P-MEC patients (stages I-IVA). Single-factor Cox regression and four machine learning techniques (random forest, LASSO, XGBoost, best subset regression) were employed for variable selection. The optimal model was derived via stepwise backward regression, Akaike Information Criterion (AIC), and Area Under the Curve (AUC). Bootstrap resampling facilitated internal validation, while prediction accuracy was gauged through C-index, time-dependent ROC curve, and calibration curve. The model's clinical relevance was ascertained using decision curve analysis (DCA). The study found 3-, 5-, and 10-year OS rates of 0.887, 0.841, and 0.753, respectively. XGBoost, BSR, and LASSO stood out in predictive efficacy, identifying seven key prognostic factors including age, pathological grade, T stage, N stage, radiation therapy, chemotherapy, and marital status. A subsequent nomogram revealed a C-index of 0.8499 (3-year), 0.8557 (5-year), and 0.8375 (10-year) and AUC values of 0.8670, 0.8879, and 0.8767, respectively. The model also highlighted the clinical significance of postoperative radiotherapy across varying risk levels. Our prognostic model, grounded in machine learning, surpasses traditional models in prediction and offer superior visualization of variable importance.

Left lower lobe sleeve resection for the clear cell variant of pulmonary mucoepidermoid carcinoma: A case report.

BACKGROUND: Pulmonary mucoepidermoid carcinoma (PMEC) is a rare malignancy that arises from minor salivary glands within the tracheobronchial tree. The clear cell variant of PMEC is exceptionally uncommon and presents notable diagnostic challenges, primarily attributable to its morphological similarity to other tumors containing clear cells. CASE SUMMARY: A 22-year-old male, formerly in good health, came in with a two-month duration of persistent cough and production of sputum. Subsequent imaging and bronchoscopy examinations revealed a 2 cm tumor in the distal left main bronchus, which resulted in complete atelectasis of the left lung. Further assessment via positron emission tomography/computed tomography scans and endoscopic biopsy confirmed the primary malignant nature of the tumor, characterized by clear cell morphology in most of the tumor cells. The patient underwent a left lower lobe sleeve resection accompanied by systematic mediastinal lymph node dissection. Molecular pathology analysis subsequently revealed a CRTC3-MAML2 gene fusion, leading to a definitive pathological diagnosis of the clear cell variant of PMEC, staged as T2N0M0. After surgery, the patient experienced a smooth recovery and exhibited no signs of recurrence during the one-and-a-half-year follow-up period. CONCLUSION: This article describes an unusual case of a clear cell variant of PMEC characterized by the presence of a CRTC3-MAML2 gene fusion in a 22-year-old male. The patient underwent successful left lower lobe sleeve resection. This case underscores the distinctive challenges associated with diagnosing and treating this uncommon malignancy, underscoring the importance of precise diagnosis and personalized treatment strategies.

High-grade salivary carcinomas: A current insight on diagnostic pathology and the key to clinical decision making.

High-grade carcinomas of the salivary glands are a group of several tumor entities with highly malignant histologic appearances, and have an aggressive biological behavior accompanied by poor a prognosis. In general, they require more intensive treatment than low- or intermediate-grade carcinomas. High-grade salivary carcinomas are rare and the microscopic features often overlap between different tumor types, making an appropriate diagnosis challenging in daily practice settings. However, with recent rapid advances in molecular pathology and molecular-targeted therapy in this field, there is a growing need to properly classify tumors, rather than just diagnosing the cases as "high-grade carcinomas". This leads to specific treatment strategies. In this article, we review representative high-grade salivary gland carcinomas, including salivary duct carcinoma and its histologic subtypes, high-grade mucoepidermoid carcinoma, solid-type adenoid cystic carcinoma, and high-grade transformation of low- or intermediate-grade carcinomas, and discuss their differential diagnoses and clinical implications. Other rare entities, such as neuroendocrine carcinoma, NUT carcinoma, and metastatic carcinoma, should also be considered before diagnosing high-grade carcinoma, NOS. Of these tumors, salivary duct carcinoma has received the most attention because of its strong association with androgen deprivation and anti-HER2 therapies. Other tumor-type-specific treatments include anti-TRK therapy for high-grade transformation of secretory carcinoma, but further therapeutic options are expected to be developed in the future. It should be emphasized that detailed histological evaluation with adequate sampling, in addition to the effective use of molecular ancillary tests, is of the utmost importance for a suitable diagnosis.

Expanding the cytological and architectural spectrum of mucoepidermoid carcinoma: The key to solving diagnostic problems in morphological variants.

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumor. Varying sized cysts and sheets composed of three cell types (epidermoid, intermediate, and mucous cells) with varying degrees of atypia form the characteristic histological appearance of MEC. MEC frequently contains a wide variety of modified tumor cells and can be entirely cystic or completely solid. Under these circumstances, MEC requires critical differentiation from many mimickers, ranging from simple cysts and benign tumors to high-grade carcinomas. Tumor-associated lymphoid proliferation and sclerotic changes in the stroma also contribute to diagnostic difficulties. Several well-known diagnostically challenging variants (oncocytic, clear cell, spindle cell, and sclerosing) exist in MEC. With the advent of studies on specific CRTC1/3::MAML2 fusion genes in MEC, newly proposed subtypes have emerged, including Warthin-like and non-sebaceous lymphadenoma-like MECs. In addition to the recently defined mucoacinar variant with a serous cell phenotype, MEC devoid of squamous differentiation has also been reported, implying the need to reconsider this basic concept. In this article, we outline the general clinical features and MAML2 status of conventional MEC and review the cytoarchitectural subtypes, with an emphasis on a pitfall in the interpretation of this histologically diverse single entity.

Analysis of local, regional, and distant recurrence of disease in mucoepidermoid tumors of larynx: A systematic review.

The aim of this systematic review is to analyze epidemiology, clinical presentation, histopathological features, treatment and oncological outcomes in laryngeal mucoepidermoid cancer (MEC) in order to improve the knowledge on the management of such a rare malignant neoplasm. Specifically, authors highlight patients' and tumors' features about local, regional, and distant recurrence of disease. PRISMA 2020 guidelines were applied in this systematic literature review. A computerized search was performed using the Embase/Pubmed, Scopus, and Cochrane databases, for articles published from 1971 to December 2023. A descriptive and univariate analysis including selected papers with low or intermediate risk of bias was performed. Twenty-seven papers (11 case series and 16 case reports) were included in this review. Fifty-six patients were included in the analyses, with a mean age of 56.7 years; 84% of them were males. Most patients (86%) underwent a primary surgical approach. Clinical stage was reported as follows: early stage (26 patients) and locally advance and advanced stage (19 patients). Overall survival (OS) and disease-free survival (DFS) at 2 years was 80% and 78%, respectively. The mean time to local recurrence was 18.7 months (range 8-36 months). The survival after recurrence is about 85% and 70% at 5 years, respectively. The mean time of lymph node recurrence was 14.7 months (range 7-19 months). Finally, the mean time of distant recurrence was 15 months (range 7-36 months) with a poor prognosis: all patients died due to the disease in a range of 0-7 months after metastasis evidence. Laryngeal MEC is a rare neoplasm of minor salivary glands in the larynx. No guidelines or indications about the management of this neoplasm are reported in the literature. The lower incidence of regional recurrence of the disease and the better OS and DFS underline how the prognosis of MEC is more favorable respect to other malignant histotypes.

Mucoepidermoid carcinoma-a rare salivary gland-type tumor of the breast: are we dealing with primary or secondary?-a case report and literature review.

Background: Salivary gland-like tumors are extremely unusual in the breast, and their histology is very similar to primary salivary gland neoplasms. Mucoepidermoid carcinoma (MEC), a common salivary gland tumor, displays an infrequent occurrence in the breast, accounting for a mere 0.2-0.3% incidence. Given its rarity, it is critical to accurately distinguish it from metastatic cases before diagnosing it as a primary breast MEC for appropriate treatment. Currently, there is no consensus on the treatment of MEC, and there is a paucity of literature highlighting the ideal treatment modality, especially for estrogen receptor (ER)-positive cancers. Therefore, the aim of our case report was to underscore the diagnostic process, surgical and adjunctive treatments for our patient with ER-positive, progesterone receptor (PR)-negative and human epidermal growth factor receptor 2 (HER2)-negative MEC while also conducting a literature review to contribute to the limited existing data. Case Description: A 67-year-old African American woman presented with a lobulated 3.1-cm left breast mass on mammography, for which she underwent ultrasound-guided core needle biopsy that revealed invasive carcinoma with squamous differentiation. The carcinoma was ER-positive, PR-negative and HER2-negative. Subsequently, she underwent a lumpectomy with sentinel lymph node biopsy. Her final pathology revealed an intermediate-grade MEC with negative lymph nodes. She had a past medical history of benign salivary gland tumor, as well as a family history of BReast CAncer gene 1 (BRCA1)-associated breast cancer in her daughter. Conclusions: MEC of the breast is a rare tumor with a relatively favorable overall prognosis. The early and precise diagnosis of this condition plays a pivotal role in formulating effective treatment strategies and ensuring positive survival rates. Nonetheless, future studies are recommended to further explore the role of surgical approaches and adjuvant therapy to improve treatment outcomes.

Central Mucoepidermoid Carcinoma in the Mandible Mimicking Dentigerous Cyst: A Report of a Rare Case.

Mucoepidermoid carcinoma is a rare neoplasm of the salivary gland of which the intraosseous variety is commonly observed with a female predilection and the affected side is more commonly in the mandible. It is usually perceived as an asymptomatic swelling that increases in volume over a few months to a year. They more frequently present as a cortical bulging and are mostly discovered as an accidental finding in a routine radiograph as a well-defined unilocular or multilocular radiolucency resembling an odontogenic cyst. The most widely accepted treatment is radical surgical resection due to its recurrence or metastatic nature. The current case is quite unusual developing in the posterior jaw as a result of an impacted third molar in a 22-year-old female patient.

Re-evaluating a historic cohort of sinonasal and skull base mucoepidermoid carcinoma: an institutional experience.

AIMS: Primary mucoepidermoid carcinomas (MECs) of the sinonasal tract and nasopharynx are rare entities that represent a diagnostic challenge, especially in biopsy samples. Herein, we present a case series of MECs of the sinonasal and skull base and its mimics to evaluate the clinicopathological and molecular characteristics in order to avoid misdiagnosis. METHODS: We reviewed the pathology records of patients diagnosed from 2014 to 2022. Thirty MECs were consecutively diagnosed during that period. RESULTS: Based on morphological and fluorescence in situ hybridization (FISH) analyses, 30 tumors originally diagnosed as MECs were separated into MAML2 fusion-positive (7 cases) and MAML2 fusion-negative groups (23 cases), in which 14 tumors were positive for the EWSR1::ATF1 fusion; these tumors were reclassified to have hyalinizing clear cell carcinoma (HCCC). The remaining nine MAML2 FISH negative cases were reconfirmed as squamous cell carcinoma (SCC, 3 cases) which showed keratinization and high Ki-67 expression; DEK::AFF2 carcinomas (2 cases), in which DEK gene rearrangement was detected by FISH; and MECs as previously described (4 cases) with typical morphological features. Including 7 MAML2 rearrangements tumors, 11 MEC cases had a male-to-female ratio of 4.5:1, and 6 tumors arose from the nasopharyngeal region, while 5 tumors arose from the sinonasal region. The prognosis of this series of salivary gland-type MECs was favorable. CONCLUSIONS: Our study confirmed that HCCC runs the risk of being misdiagnosed as MEC in the sinonasal tract and nasopharynx, particularly with biopsy specimens. Careful histological evaluation with supporting molecular testing can facilitate pathological diagnoses.

Salivary gland-type cancers: cross-organ demographics of a rare cancer.

BACKGROUND: Salivary gland-type cancers (SGTCs) are histologically heterogeneous and can affect organs other than the salivary glands. Some tumors outside the salivary glands are diagnosed on their unique histological characteristics. Comprehensive cross-organ studies on SGTCs are limited. METHODS: We retrospectively analyzed the data of patients with salivary duct carcinoma (SDC), adenoid cystic carcinoma (AdCC), mucoepidermoid carcinoma (MEC), epithelial-myoepithelial carcinoma (EMC), acinic cell carcinoma (AcCC), and polymorphous adenocarcinoma (PAC) who visited our institution between 2009 and 2019. The primary tumor sites were classified into four categories; major salivary glands, head/neck (H/N) excluding (exc) major salivary glands (MSG) regions, broncho-pulmonary regions, and "others". H/N exc MSG was further divided into three subcategories, nasal/paranasal sinus, oral and pharynx/larynx. RESULTS: We identified 173 patients with SGTCs, with SDC, AdCC, MEC, EMC, AcCC, and PAC accounting for 20%, 42%, 27%, 3%, 8%, and 1% of the cases, respectively. The most frequent primary site was the major salivary glands (64%), followed by H/N exc MSG regions (27%), broncho-pulmonary regions, and "others", thus non-salivary gland origins accounted for 9% of all cases. Patients with SDC, MEC, AcCC, or SGTC of the major salivary glands and broncho-pulmonary regions were more frequently treated by surgery. The overall survival time of the patients with MEC was significantly better than that of patients with SDC or EMC. CONCLUSIONS: This cross-organ study highlights the clinical significance of SGTCs, underscoring the need for developing novel therapies for this rare disease entity.

TGFß signaling pathway in salivary gland tumors.

OBJECTIVE: Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFß signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFß signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFß cascade. DESIGN: Thirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR. RESULTS: Cases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFß signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC. CONCLUSIONS: Our study demonstrated the differential expression of TGFß cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

SALTT study: A retrospective analysis of 111 SAlivary gland tumors of Lung and Tracheobronchial Tree.

INTRODUCTION: Primary pulmonary salivary gland-type tumours (PPSGT) are rare lung neoplasms arising from submucosal seromucinous glands in the central airway. METHODS AND RESULTS: We retrospectively analysed the clinicopathological features of 111 PPSGTs diagnosed at our institute between 2003 and 2021. The mean age at diagnosis was 43.8 years(range 6-78 years) and a male-to-female ratio of 2:1. On imaging, 92 % of cases had centrally located tumours and 37.3 % were early stage. The histopathological types included 70 cases (63 %) of mucoepidermoid carcinoma (MEC), 31 cases (27.7 %) of adenoid cystic carcinoma (ADCC), two cases of myoepithelial carcinoma, one case each of acinic cell carcinoma (ACC), clear cell carcinoma (CCC), epithelial myoepithelial carcinoma (EMC) and 5 others [including adenocarcinoma of minor salivary gland origin(n = 3), carcinoma with sebaceous differentiation(n = 1) and poorly differentiated carcinoma of salivary gland type(n = 1)]. The size of the tumours found in the resection specimens ranged from 1 cm to 13 cm, with an average size of 4.9 cm. High-risk attributes such as lymphovascular invasion (LVI), perineural invasion (PNI), pleural involvement, positive resection margins, and nodal metastasis were identified in 15.3 %, 15.3 %, 13.6 %,15.2 % and 6.7 % of cases, respectively. These attributes were found to be more frequent in ADCC than in MEC. Surgery was the main treatment modality [68/84 (80 %) cases]. ADCC cases had more recurrence and distant metastasis than MEC cases. The 3- year overall-survival (OS) and recurrence-free survival(RFS) were better in patients with age lesser than 60 years(p-value <0.0001), low pT stage (p-value 0.00038) and lower grade of MEC(p-value-0.0067). CONCLUSION: It is crucial to have an acquaintance with the morphologic spectrum and immunophenotypic characteristics of PPSGT to recognize them in this unusual location. In tandem, it is crucial to differentiate them from conventional primary non-small cell lung carcinoma, as the management protocols and prognostic implications differ significantly.

Parotid Mucoepidermoid Carcinoma in a Pediatric Patient: A Case Report.

Mucoepidermoid carcinomas (MECas) are malignant epithelial salivary gland neoplasms composed of a variable mixture of epidermoid and mucus-secreting cells arising from the ductal epithelium. Of all salivary gland tumors, MECas are the most common malignant lesions of the parotid gland. This case report aims to present a 14-year-old female patient with a history of progressive enlargement of a 3 cm in diameter, painless, mobile mass located at the parotid gland without facial nerve dysfunction. The lesion was exhaustively studied preoperatively, and studies were carried out. Contrast-enhanced computerized tomography (CECT) showed an increase in nodule numbers and size at the level of both the jugular and posterior cervical chains. In contrast, the gland's fine needle aspiration (FNA) showed a mucinous background. The histologic depiction established that the tumor was MECa of the parotid gland. The literature reviews on MECa encompass discussions about its prevalence, etiology, histological findings, and treatment.

Low-grade mucoepidermoid carcinoma mimicking benign cystic lesions in the salivary gland: A diagnostic dilemma.

Mucoepidermoid carcinoma (MEC) is a common malignancy arising in the parotid gland. The diagnosis of MEC is typically based on its morphological features alone, characteristically containing mucocytes, intermediate cells and epidermoid cells. However, when cystic degeneration is diffuse, it is challenging to distinguish MEC from other benign cystic tumors. This is a case report of a 58-year-old Caucasian man who presented with a parotid mass. H&E sections of the mass reveal multiloculated cysts lined by bland-looking epithelium with only rare papillary architectures. The papillary proliferation contains mucocytes, and epidermoid cells highlighted by the p63 immunohistochemistry study. The diagnosis was confirmed by FISH result of positive MAML2 (11q21) rearrangement. Patient underwent parotidectomy and is disease-free 6 months post-surgery. MEC with cystic degeneration is a common diagnostic pitfall which can mimic many benign lesions in the salivary gland. We present a rare case with MEC with extensive cystic change, its molecular and pathologic findings and review the diagnostic features of MEC, its benign mimickers and useful tools for distinguishing these entities.

Galeo-Pericranial Flap-A Rich Pedicle Flap for Temporisation of Large Maxillofacial Defect: A Case Report.

Reconstruction of large facial defects is quite a challenging and difficult task. Various surgical options are available, each with its challenges and complications. Galeo-pericranial flap has provided a suitable technique for reconstruction of radical parotidectomy defects with satisfactory outcomes. A 50-year-old farmer with a histologically diagnosed mucoepidermoid carcinoma of the right parotid gland of 15 years duration had radical parotidectomy and reconstruction of the defect with galeo-pericranial flap. The patient was followed up for 2 years, and the flap was completely taken with no donor site morbidity.

Rapid On-site Evaluation (ROSE) Cytology of Mucoepidermoid Carcinoma and its Diagnostic Pitfalls: a Case Report.

Fine needle aspiration cytology (FNAC) is a basic tool used for the preoperative diagnosis of superficial parotid swellings. Mucoepidermoid carcinoma accounts for approx. 5-10% of all salivary gland tumors. However, due to its morphologic heterogenicity, this tumor poses diagnostic difficulties in its interpretation. This is a case of a 45-year-old male with a history of recurrent swelling in the left infra-auricular region. Cytology with rapid on-site evaluation revealed a triphasic population of basaloid cells, squamoid cells, and intermediate cells on a mucoid background and reported as low-grade mucoepidermoid carcinoma in recurrence. The presence of a triphasic cellular component (mucous, intermediate, and squamoid cells) may not be seen in all cases of mucoepidermoid carcinoma (MEC) for definitive diagnosis. Clinico-radiological correlation, rapid on-site evaluation (ROSE), and high index of suspicion related to cystic lesions are important for early diagnosis and prompt treatment.