Unraveling an Unusual Presentation of Parotid Malignancy: A Case Report.

Mucoepidermoid carcinoma (MEC) is a salivary gland tumor commonly arising from the parotid gland. MEC has various presenting symptoms, including a painless, slow-growing mass below or anterior to the ear lobule. However, an unusual presentation can also be in the form of post-auricular swelling. Other more common benign differentials for post-auricular swelling include lymphadenopathy, epidermoid cysts, and lipomas. Thus, diagnosing a postauricular swelling as MEC solely based on clinical presentation is challenging, and a high suspicion, as well as a multidisciplinary approach with various radiological investigations such as computed tomography (CT) and magnetic resonance imaging (MRI), are required in collaboration with histopathological assessment for an accurate diagnosis of this malignancy. Prognosis depends on various factors, including the grade of the tumor, the patient's age, and comorbidities, as well as the stage at the time of diagnosis. Early diagnosis and surgical intervention are the mainstays of treatment, which can be followed by adjuvant radiotherapy based on the stage of the malignancy. This is a report of a patient who presented with post-auricular swelling, which was initially misdiagnosed as a benign necrotic lymph node. After further evaluation, it was found to be a mucoepidermoid carcinoma of the parotid gland, which was managed by surgical excision and radiotherapy.

Case report: The diagnostic pitfall of Warthin-like mucoepidermoid carcinoma.

Warthin-like mucoepidermoid carcinoma (WL-MEC) is a newly reported variant of mucoepidermoid carcinoma. Its histological feature is easy to confused with metaplastic Warthin Tumor, and its relationship with Warthin tumor in histogenesis is controversial. In this study, we presented two cases of WL-MEC, discussing their clinicopathological and molecular features. Notably, one case was initially misdiagnosed during the first onset of the tumor. Case 1 was a 60-year-old female with a mass in the right parotid gland. Case 2 featured a 29-year-old male who developed a lump at the original surgical site 6 months after a "Warthin tumor" resection from the submandibular gland. Histologically, both tumor exhibited a prominent lymphoid stroma and cystic pattern, accompanied by various amounts of epithelial nests composed of squamoid cells, intermediate cells and mucinous cells. The characteristic eosinophilic bilayer epithelium of Warthin tumor was not typically presented in either case. Both cases tested positive for MAML2 gene rearrangement. To contextualize our findings, we conducted a comprehensive review of forty-eight WL-MEC cases documented in the English literature, aiming to synthesizing a reliable differential diagnostic approach. WL-MEC is a rare yet clinically relevant variant, posing a diagnostic pitfall for pathologists. Our study underscores the importance of a meticulous evaluation of both clinical and histological features, coupled with the detection of MAML2 rearrangement, as a credible method for distinguishing WL-MEC from other benign and malignant lesions, particularly metaplastic Warthin tumor.

Role of p63 in Determining the Histogenesis of Low-Grade Neoplasms versus Cystic Lesion.

The biological nature of salivary gland neoplasms and the overlapping characteristics that result from the heterogeneity of the cells of origin make diagnosis difficult. Hence, we intend to present a case of low grade mucoepidermoid carcinoma (MEC) on the palate and to understand the importance of biomarker such as p63 in the early diagnosis of tumor as it also has a role in its histogenesis. A 53-year-old female reported with a unilateral swelling for 3 months on posterolateral palatal region of the right side. Clinical differentials for such palatal swellings include a varied spectrum of lesions such as reactive, benign, and malignant lesions. Based on the incisional and excisional biopsy, histopathological findings and immunohistochemical examination with p63 the case were diagnosed with low grade MEC. The tumor cell differentiation in MEC could be the result of multiplicity of differentiation pathways leading to the formation of various histological patterns. This case report highlights the complexity of salivary gland pathology diagnosis and role of specific tumor marker such as p63 as an early marker for differentiation of salivary gland tumor such as low grade MEC from other cystic lesions occurring on the palate.

Impact of childhood/adolescent cancer history on prognosis in parotid mucoepidermoid carcinoma.

Our goal was to assess the impact of childhood/adolescent cancer history on overall survival (OS) and disease-specific survival (DSS) in patients with parotid mucoepidermoid carcinoma (MEC). Patients who underwent surgical treatment for primary parotid MEC and those with a second malignancy of parotid MEC were retrospectively identified from the Surveillance, Epidemiology, and End Results (SEER) database. The primary outcome variables were OS and DSS. The hazard ratios (HRs) of these survival rates associated with cancer history were analysed using Cox regression models. In total, 2681 patients were included, 263 of whom had a second malignancy. The 10-year OS rates in the primary (72%) and second malignancy groups (59%) were significantly different. Cox regression confirmed that a history of cancer tended to decrease OS (p = 0.062, HR: 1.28, 95% confidence interval: 0.99 to 1.64). Subgroup analyses showed that a history of solid tumour as opposed to haematological cancer predicted worse OS, with central nervous system tumours exhibiting a more significant influence than others (p = 0.030 vs p = 0.088). Cancer history was not related to DSS. A history of childhood/adolescent cancer negatively influenced the prognosis of patients with parotid MEC, and this effect was primarily driven by a history of solid malignancy.

Mucoepidermoid carcinoma of the hard palate mimicking a dental abscess: Case report.

Mucoepidermoid carcinoma is a malignant tumor that arises from the salivary glands. The recommended treatment strategy typically involves surgical intervention, sometimes complemented by radiotherapy, depending on the histological grade of the tumor. A case of a 22-year-old female patient without medical history was described. The clinical examination revealed a bluish lesion located on the hard palate. The histological examination confirmed the diagnosis of a low-grade mucoepidermoid carcinoma. Resection of the lesion was performed and oro-nasal communication was immediately closed by a prosthetic obturator and later on by a rotational palate flap. The patient was followed up for 12 months, and there was no evidence of any recurrence. This article highlights the importance of prompt clinical diagnosis of such lesions and provides an opportunity to review these cancer therapeutic measures to reduce postoperative morbidity.

Differential Expression of Mucin in Salivary Gland Tumours.

Background and Objectives: Mucin has been implicated via various mechanisms in the development and growth of tumour cells. However, mucin expression studies in salivary gland tumours are limited, especially with samples from minor salivary glands. This study aims to investigate and compare mucin expression in benign and malignant salivary gland tumours of minor and major salivary gland origins. Materials and Methods: Special stains were used to stain neutral mucin (Periodic acid Schiff), sialomucin (Alcian Blue) and sulfomucin (Aldehyde Fuschin) within tissues from six normal salivary glands and 73 salivary gland tumours including 31 pleomorphic adenomas, 27 mucoepidermoid carcinomas, and 15 adenoid cystic carcinomas. A semi-quantitative approach was used to evaluate mucin expression within ductal lumens. Sialomucin was the most expressed mucin in all salivary gland tumours, regardless of origin. Results: A significant difference was observed in the mucin expression between benign and malignant salivary gland tumours, as pleomorphic adenoma showed three times significantly higher expression of sialomucin compared to mucoepidermoid carcinoma and adenoid cystic carcinoma (p = 0.028). Pleomorphic adenomas of major glands showed 42 times significantly higher expression of sialomucin compared to those of minor glands (p = 0.000). Conclusions: Sialomucin content in pleomorphic adenomas of major glands was vastly increased compared to that in minor glands. Differential sialomucin expression in benign and malignant salivary gland tumours suggests a role in diagnosing of borderline salivary gland tumours.

Clinical presentation and treatment of four children with pulmonary mucoepidermoid carcinoma.

Primary lung cancer in childhood is extremely rare, with an incidence rate of less than 2/100,0000, and pulmonary mucoepidermoid carcinoma (PMEC), is even rarer. Their symptoms are usually not specific, and there are no guidelines for their management, which makes their clinical management a challenge for pediatricians. The purpose of this report is to discuss the clinical presentation, positive signs, examinations, pathological characteristics, surgical modalities, chemotherapy regimens, and prognosis in children. The clinical data of four patients diagnosed with PMEC at the Children's Hospital of Chongqing Medical University from June 2021 to November 2022 were retrospectively analyzed, and their clinical features, treatment, and prognosis were summarized. Among them, two were male and two were female; their ages ranged from 3 years and 10 months to 10 years and 11 months, and all were staged according to tumor node metastasis classification (TNM). Immunohistochemical tests were performed in all children, among which four cases were positive for cytokeratin (CK), two cases were positive for CK7, four cases were positive for p63, about 5-10% of tumor cells were positive for Ki67. Among the four children, three had surgery alone and one had surgery + chemotherapy. All four children are presently living, with no evidence of tumor recurrence or metastasis. PMEC in children is very rare, and its age of onset and symptoms are not specific, and there is no obvious correlation with gender. Its diagnosis mainly relies on pathomorphological diagnosis, and immunohistochemical detection has no specific performance. The prognosis of children with PMEC is related to the clinical stage and whether surgery is performed. Whether further chemotherapy or radiotherapy is needed for patients who cannot undergo surgical resection and for those who have a combination of distant metastases requires further clinical studies.

Clinical presentation and treatment of 4 children with pulmonary mucoepidermoid carcinomaLung cancer in childhood is extremely rare, occurring at a rate of less than 2/1000000, and a type of lung cancer called pulmonary mucoepidermoid carcinoma (PMEC), is even rarer. The symptoms are usually not specific, and there are no guidelines for its management, which is a challenge for doctors. The purpose of this report is to discuss the signs and symptoms medical examinations, disease characteristics, surgical procedures, chemotherapy regimens and prognosis in children with pulmonary mucoepidermoid carcinoma. The clinical data of four patients diagnosed with pulmonary mucoepidermoid carcinoma at the Children's Hospital of Chongqing Medical University from June 2021 to November 2022 were analyzed, and their clinical features, treatment and prognosis were summarized. All four children are currently alive, and there is no recurrence or spread of the tumor after treatment. We have discussed various aspects of the disease, such as the rate of occurrence, causes, signs and symptoms, the way in which it might be diagnosed and treated, and the survival rate after operation, hoping to provide some insights for future work.

Salivary gland tumors: an audit from a tertiary care centre in Northern India.

Salivary gland tumors are relatively rare and can exhibit various clinical behaviors. The study aims to understand the natural history, pathology, diagnostic workup, and treatment strategies for these tumors to improve patient outcomes. The audit included patients with salivary gland tumors detected through radiology or cytology. Patients underwent surgery, with some receiving adjuvant treatment. Demographic information, treatment interventions, and survival outcomes were analyzed using SPSS software. A total 89 as malignant salivart gland tumours were audited Malignant tumors were predominantly found in the parotid gland, with fewer cases in the minor salivary gland and submandibular gland.The median age of presentation was 47 years, and the majority of patients were male. The study examined various pathological and clinical factors, including tumor stage, nodal status, and the presence of facial palsy. Surgical procedures and histological types of tumors were documented. Adverse histological features like positive margins, lymph node positivity, lympho-vascular invasion, extracapsular spread, and perineural invasion were noted. POSTOP RT was administered to high-risk patients. Most malignant salivary gland tumors were found in the parotid gland, while minor salivary gland tumors were underrepresented in the audit. Surgical practices were diverse. Radiotherapy protocols were relatively standardized. The study found that certain histological features, such as lymph node positivity, margin positivity, lympho-vascular invasion, perineural invasion, and extracapsular spread, were associated with adverse effects on DFS and OS. The findings suggest that specific histological features, including LVI and ECE have emerged as independent prognostic factors for DFS and OS.

Outcome of Primary Lung Salivary Gland-Type Carcinoma: A Population-Based Study.

Introduction. Primary pulmonary salivary gland-type carcinomas are rare malignancies arising from minor salivary gland tissue in the lower respiratory tract. Given their rarity, constituting <1% of all primary lung malignancies, their epidemiological features and outcomes remain poorly documented. This study analyzed data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database to identify primary pulmonary salivary gland carcinomas, including the most prevalent tumor types. Methods. All patients diagnosed with mucoepidermoid carcinoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma, with the lung designated as the primary site between 1975 and 2019, were subject to analysis. Overall and disease-specific survival were calculated using Kaplan-Meier curves and Cox proportional hazards models. Results. The study identified 323 mucoepidermoid carcinoma, 284 adenoid cystic carcinoma, and 6 epithelial-myoepithelial carcinoma diagnosed as pulmonary salivary gland-type carcinoma. An analysis of age distribution revealed a unimodal pattern for both mucoepidermoid carcinoma and adenoid cystic carcinoma, with most patients diagnosed after age 40. Most patients were Caucasians (77% for mucoepidermoid carcinoma and 83% for adenoid cystic carcinoma). Both disease-specific and overall survival were worse for patients diagnosed at the age of 60 years or above. Race or sex did not significantly impact patient survival. High-grade mucoepidermoid carcinoma demonstrated a significantly worse prognosis than low or intermediate-grade mucoepidermoid carcinoma. Conclusion. A comprehensive review of clinical and epidemiological features of pulmonary salivary gland-type carcinomas reveals that the age of diagnosis and tumor grade are the most significant factors in determining patient survival.

A case report of pancreatic mucoepidermoid carcinoma responded to gemcitabine and paclitaxel.

Mucoepidermoid carcinoma (MEC) typically manifests in the salivary glands, but occurrences in the pancreatic gland are exceedingly rare. Surgical resection proves effective; however, pancreatic MEC is prone to metastasis, and lacking a standardized postoperative treatment. We discussed the experience of a 51-year-old female patient with pancreatic MEC who received paclitaxel and gemcitabine as postoperative care. Within a predetermined amount of time, this regimen successfully stopped the spread of metastatic tumors and returned tumor markers to normal. A Stable Disease status was achieved within 6 months after chemotherapy. In summary, gemcitabine and paclitaxel display efficacy in treating pancreatic MEC.

Primary hepatobiliary mucoepidermoid carcinoma: a case report and review of literature.

Hepatobiliary mucoepidermoid carcinoma is a rare malignant tumor comprising mucous, intermediate, and epidermoid cells. Herein, we presented a case of primary liver mucoepidermoid carcinoma preoperatively misdiagnosed as conventional intrahepatic cholangiocarcinoma. A 67-year-old male was admitted to our hospital. Preoperative laboratory tests showed increased aspartate transaminase, alanine transaminase, and carbohydrate antigen 19-9. Abdominal Computer Tomography revealed a 4.8 × 4.9 cm liver mass in segment VI. A preliminary diagnosis of intrahepatic cholangiocarcinoma was made, with undergoing partial hepatectomy. However, on histopathology, the tumor comprised a mixture of epidermoid, mucous, and intermediate cells with diffuse infiltrating at the tumor margin. On special stains, mucous and intermedia cells were positive for mucicarmine and Alcian blue, whereas epidermoid cells were positive for Keratin 5/6 and p63. Intermediate cells are also positive for p63. All tumor cells were positive for Keratin 7. The Ki-67 index was 35%. The final diagnosis was primary hepatic mucoepidermoid carcinoma. Although rare, hepatic mucoepidermoid carcinoma should be considered in the intrahepatic cholangiocarcinoma differential diagnosis. We reviewed previous studies and found that hepatobiliary mucoepidermoid carcinoma is more likely to originate from the biliary tract adjacent to the tumor.

Mucin-rich salivary gland tumors.

Salivary gland neoplasms characterized by abundant mucin production are rare but have long been recognized. Due to their scarcity, precise classification has long eluded these mucin-rich tumors. Recent molecular discoveries, however, have shed considerable light on the genetic underpinnings of mucin-rich salivary gland neoplasms. This manuscript will review the most up-to-date information on this fascinating group of salivary gland neoplasms.

White out hemithorax secondary to salivary gland type of lung cancer with metastasis in liver and bone: a case report.

BACKGROUND: Salivary gland-type lung carcinomas are uncommon neoplasms of the lung, representing less than 1% of all lung tumors. The two most common among them are adenoid cystic carcinoma and mucoepidermoid carcinoma. Although they usually have an indolent behavior, adenoid cystic carcinomas can be more aggressive, with 5-year survival as low as 55%. Very few cases are reported in literature. We report a similar rare case of salivary gland type lung carcinoma that presented for the first time with unilateral opacification of left hemithorax. CASE PRESENTATION: A 38-year-old man of North Indian origin, who was a a nonsmoker, presented with complaints of shortness of breath and cough for 1 year, which has increased in the last 2 months and was associated with significant weight loss. A frontal radiograph of the chest and computed tomography of the chest were performed, which showed a mass in the left upper lobe of the lung with its epicenter in the left main bronchus. A bronchoscopic guided biopsy was performed, and histopathology confirmed the diagnosis of lung carcinoma of salivary gland type (adenoid cystic carcinoma). There was invasion of major vessels, hence the patient was offered and started on palliative management instead of surgical treatment. In spite of palliative management of two cycles of chemotherapy and radiotherapy, the patient succumbed to the disease within 2 months from the time of diagnosis. CONCLUSION: Lung carcinoma of the salivary gland type (especially adenoid cystic carcinoma) usually presents at a later stage. The resectability of the tumor depends on the involvement of the surrounding major vessels. Interestingly, these cancers have no association with smoking. The prognosis depends on the extent of the disease at the time of diagnosis. Hence, imaging plays a major role in deciding the further plan of management.

The differential diagnosis of lymphoepithelial lesion of the salivary gland.

The differential diagnosis of salivary gland lesions with epithelial components and lymphoid stroma is often challenging. Salivary gland carcinoma with tumor-associated lymphoid proliferation, tumors composed of both epithelial and lymphoid components, lymphoid neoplasms in the salivary gland, and inflammatory lesions are all included in this category. It encompasses inflammatory lesions and neoplastic lesions. With the exception of Warthin tumors, these lesions are rare, making them more difficult to diagnose. Carcinoma showing thymus-like elements has recently been reported in the salivary gland. Similar to thymic carcinoma, tumor cells are positive for CD5 and are accompanied by T lymphocytes.

Predominantly oncocytic mucoepidermoid carcinoma of palate: A case report.

Oncocytic mucoepidermoid carcinoma (OMEC) is an uncommon variant of mucoepidermoid carcinoma. Histopathologically, it is characterised by the predominance of cells with large polygonal morphology and with an abundance of eosinophilic granules. We present a rare case of OMEC manifested as painless palatal swelling in a 25-year-old young male. The overlying mucosa was normal in appearance, with no evidence of ulceration or discharge. Histopathology examination showed the presence of sheets of mucous and intermediate cells along with cystic areas of variable sizes and shapes. On high power magnification, oncocytes were evident, showing abundant granular eosinophilic cytoplasm with central dark round nuclei. Around 75-80% tumour cell population was composed of oncocytic cells. The predominant presence of oncocytes can present diagnostic difficulties to pathologists due to overlapping features with adenoid cystic carcinoma, oncocytoma, acinic cell carcinoma, Warthin's tumour, and other oncocyte tumours. Although the presence of oncocytes is a pathognomonic feature, the role of immunohistochemistry and genetic analysis in diagnosis is discussed in the present paper. Moreover, considering its behaviour as a low-grade MEC, it is prudent to avoid an aggressive treatment strategy and prevent unwarranted morbidity. We recommend prospective studies to better understand the factors that influence the prognosis of OMEC.

Molecular Pathology of Thyroid Tumors: Old Problems and New Concepts.

The molecular signatures of many thyroid tumors have been uncovered. These discoveries have translated into clinical practice and are changing diagnostic and tumor classification paradigms. Here, the findings of recent studies are presented with special emphasis on how molecular insights are impacting the understating of RAS mutant thyroid nodules, Hürthel cell neoplasms, and unusual thyroid tumors, such as hyalinizing trabecular tumor, secretory carcinoma of the thyroid, and sclerosing mucoepidermoid carcinoma with eosinophilia. In addition, the utility of detecting actionable molecular alterations by immunohistochemistry in advanced and aggressive thyroid cancer is also discussed.

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.

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.