Sclerosing mucoepidermoid carcinoma with eosinophilia of the salivary gland: Case report and review of the literature

MAML2-rearrranged sclerosing mucoepidermoid carcinoma of submandibular gland: an incidental finding in a patient with history of recurrent sialadenitis and Sjögren's syndrome

The Sclerosing subtype of mucoepidermoid carcinoma is rare, with only 39 cases reported in literature. We present a new case of sclerosing mucoepidermoid carcinoma (SMEC) with MAML2 rearrangements. A 49-year-old woman with Sjögren's syndrome experienced recurrent submandibular sialadenitis and sialolithiasis, leading to the removal of her right gland. Postoperative imaging revealed a calcified mass in her left gland which was subsequently resected. The pathologic examination revealed a well-defined tumor with extensive fibrous stroma, predominantly epidermoid cells, and occasional mucinous components. There was a dense lymphocytic and plasma cell infiltrate at the tumor's periphery. Immunohistochemistry was positive for p40 and CK7, few IgG4+ plasma cells. No eosinophils were identified. Fluorescence in situ hybridization (FISH) revealed rearrangement of the MAML2 (11q21) region. Adjuvant radiation was not recommended because of the patient's history of autoimmune diseases and the fact that the tumor was small, localized, and had negative resection margins. The patient was advised to undergo a repeat CT scan of the neck, scheduled for 3 months later. This case highlights the importance of considering SMEC in the differential diagnosis of patients with sialolithiasis or Sjögren's syndrome.

Unusual Presentation of a Parotid Gland Malignancy: A Case Report

The most commonly occurring malignant salivary gland tumor is mucoepidermoid carcinoma (MEC). It consists of intermediate cells, squamous cells, and mucous-secreting cells. It is usually not capsulated and is identified by mucocarmine staining. Mucoepidermoid carcinoma exists in the thyroid gland and lungs as well. This report presents a case of a very rare sclerosing variant of MEC of the parotid gland in a 48-year-old patient. The patient presented with a small swelling below the left earlobe. Ultrasound-guided fine-needle aspiration cytology (FNAC) was carried out. A diagnosis of pleomorphic adenoma was given. The patient underwent a partial parotidectomy under general anesthesia. The final diagnosis was made through histopathological examination after the surgical removal of the tumor. The patient is now under close follow-up to look out for a recurrence. This case highlights the importance of recognizing and managing rare variants of MEC to optimize patient outcomes.

Detection of CSF1 gene derangement in 'sclerosing mucoepidermoid carcinoma with eosinophilia' of the parotid gland masquerading as Langerhans cell histiocytosis

Key Clinical Message

When faced with a slowly enlarging firm mass in the parotid gland accompanied by a histological picture of unusual sclerosis with abundant Langerhans cells and eosinophilic infiltrates, sclerosing mucoepidermoid carcinoma with eosinophilia should be considered as one of the differential diagnoses. Further studies are warranted for accurate diagnosis and appropriate treatment.

Abstract

Sclerosing mucoepidermoid carcinoma of the salivary gland with eosinophilia is a rare tumor mostly negative for the MAML2 rearrangement commonly seen in salivary mucoepidermoid carcinoma. It was not listed as an entity in the 2022 WHO Classification of Head and Neck Tumors. We presented one case initially diagnosed as Langerhans cell histiocytosis and recurred as a frankly invasive carcinoma. Molecular studies showed CSF1 gene derangement and provided new understanding concerning the Langerhans cell and eosinophilic reaction. Further molecular studies on this entity would throw light on its oncogenesis and refine its nomenclature.

Primary Thyroid Mucoepidermoid Carcinoma (MEC) Is Clinically, Prognostically, and Molecularly Different from Sclerosing MEC with Eosinophilia: A Multicenter and Integrated Study

Mucoepidermoid carcinoma (MEC) and sclerosing MEC with eosinophilia (SMECE) are rare primary thyroid carcinomas. In this study, we aimed to present our multicenter series of MEC and SMECE and integrated our data with published literature to further investigate the clinicopathological characteristics and prognoses of these tumors. We found 2 MECs and 4 SMECEs in our multicenter archives. We performed fluorescence in situ hybridization (FISH) to determine the MAML2 gene rearrangement. We screened for mutations in BRAF, TERT promoter, and RAS mutations using Sanger sequencing and digital polymerase chain reaction. Histopathologically, MECs and SMECEs were composed of two main cell types including epidermoid and mucin-secreting cells, arranged in cords, nests, and tubules. SMECEs were characterized by a densely sclerotic stroma with abundant eosinophils. We did not detect any MAML2 fusion in any of our cases. Two MEC cases harbored concomitant BRAF p.V600E and TERT C228T mutations. RAS mutations were absent in all cases. Concurrent foci of another thyroid malignancy were more commonly seen in MECs (p < 0.001), whereas SMECEs were associated with chronic lymphocytic thyroiditis (p < 0.001). MECs and SMECEs had equivalent recurrence-free survival (RFS) but MECs conferred significantly dismal disease-specific survival (DSS) as compared to SMECEs (p = 0.007). In conclusion, MECs and SMECEs not only shared some similarities but also demonstrated differences in clinicopathological characteristics, prognoses, and molecular profiles. SMECEs had a superior DSS in comparison to MECs, suggesting that they are low-grade cancers. This could help clinicians better evaluate patient outcomes and decide appropriate treatment plans.

Concomitant presentation of eosinophilic or oncocytic mucoepidermoid carcinoma, immunoglobulin G4-related disease, and adult-onset asthma and periocular xanthogranuloma: Case report of 3 uncommon clinical entities

RATIONALE

Immunoglobulin (Ig) G4-related disease (IgG4-RD) reportedly has a strong relationship with adult-onset asthma and periocular xanthogranuloma (AAPOX) and may be linked to sclerosing mucoepidermoid carcinoma (MEC). We present a rare case of IgG4-RD and AAPOX occurring in a patient with resected eosinophilic or oncocytic MEC.

PATIENT CONCERNS

A 52-year-old woman was referred to our rheumatology clinic in 2020 to be evaluated for suspected IgG4-RD.

DIAGNOSES

The patient had diagnoses of periorbital xanthelasmas, worsening glucocorticoid-dependent chronic rhinosinusitis and adult-onset asthma, and cervical lymphadenopathy persisting 2 years after resection of a low-grade MEC of a minor salivary gland.

INTERVENTIONS

Because the patient's symptomatic relief was glucocorticoid dependent, IgG4-RD was suspected, and she was referred to our medical center. Her amylase and lipase levels were elevated. Serum IgG4 levels were initially within normal limits, but IgG4-RD was diagnosed because of the presence of lymphadenopathy and evidence of pancreatitis, which was shown on positron emission tomography/computed tomography. Furthermore, the IgG4 levels later increased without explanation. After the patient began combination therapy with a glucocorticoid (prednisone) and methotrexate, her symptoms improved but recurred when the daily oral glucocorticoid dosage decreased below 10 mg. An excisional biopsy of her right submandibular gland in 2021 yielded results consistent with IgG4-RD. In addition, AAPOX was diagnosed, given the presence of periocular edema and plaques, adult-onset asthma, and rhinosinusitis.

OUTCOME

The patient was carcinoma free at last follow-up and was receiving medication to treat the other conditions.

LESSONS

The diagnosis of these 3 concomitant, uncommon entities required approximately 7 years of medical investigations. Clinicians should know that IgG4-RD, AAPOX, and MEC may occur together.

Reevaluation of Salivary Lymphadenoma: A Subgroup Identified as Warthin-like Mucoepidermoid Carcinoma Following Molecular Investigation for MAML2 Rearrangement

CONTEXT.—

Both salivary lymphadenomas (LADs) and Warthin-like mucoepidermoid carcinoma (MEC) contain components of epithelium and lymphoid stroma and their differential diagnosis can be difficult on the basis of morphology alone.

OBJECTIVE.—

To clarify whether Warthin-like MEC was diagnosed as a LAD, and to compare their clinicopathologic features.

DESIGN.—

A total of 16 LAD cases were analyzed for MAML2 rearrangement by using fluorescence in situ hybridization, and the clinical, histologic, immunohistochemical, and prognostic features were compared between MAML2 rearrangement-positive and MAML2 rearrangement-negative groups.

RESULTS.—

Among the 16 cases investigated, 9 harbored a MAML2 rearrangement and were reclassified as Warthin-like MEC. The remaining 7 cases were classified as LADs with 1 nonsebaceous and 6 sebaceous cases. The patients with Warthin-like MEC had a wider age range (10-75 years) than the patients with LADs (36-68 years). Histologically, 2 of the 9 Warthin-like MECs (22.2%) showed focal invasion, whereas all the LADs had complete capsules. Warthin-like MECs exhibited a diverse epithelial cell morphology, including basaloid, glandular, cuboidal, epidermoid, with mucinous cells, although these cytologic features were seen only focally in some cases. Nonsebaceous LAD was composed of basaloid and glandular epithelial cells predominantly. In sebaceous LAD, the epithelial cells were composed of basaloid and large foamy sebaceous cells. In all cases, the stroma was composed mainly of lymphocytes accompanied by lymphoid follicles, although plasma cell infiltration could be much heavier in Warthin-like MEC. All the patients had a good outcome after a longer follow-up (3-166 months).

CONCLUSIONS.—

Warthin-like MEC can be misdiagnosed as a LAD owing to overlap in clinicopathologic features of the 2 entities. Careful histologic evaluation and detection of MAML2 rearrangement can facilitate their differential diagnosis.

Sclerosing mucoepidermoid carcinoma of the salivary glands: report of three cases with special concern to the counterpart accompanied by eosinophilia

Sclerosing mucoepidermoid carcinoma (SMC) is described as a "sclerosing variant" of mucoepidermoid carcinoma, and it is characterized by dense fibrosis and sclerosis of the stroma. SMC with eosinophilia (SMCE) is another and more rare subtype characterized by eosinophilia in addition to the sclerotic stroma common to SMC. However, unlike SMC, SMCE is not listed in the current 4th edition of WHO classification. Here, we describe three cases: one SMC in the parotid gland, one SMCE in the submandibular gland and one SMCE in the minor salivary gland of the oral cavity. The patients included a 71-year-old Japanese male, a 74-year-old Japanese female, and an 81-year-old Japanese female. They each complained of mass formation and underwent surgical resection. Histologically, the tumors mainly consisted of squamous cells with scarce keratinization that formed irregular large and small nests along with cystic structures containing mucous cells against the background of sclerotic stroma. One oral SMCE showed fine nesting and trabecular invasion. The two SMCEs included dense aggregates of eosinophils as well as more prominent lymphoid infiltration. Fluorescence in situ hybridization for MAML2 confirmed split signals in SMC, but not in SMCE.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia in conjunction with parotid basal cell adenoma: Cytologic, histologic, and molecular features

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) is a rare malignancy in the thyroid: only 56 cases with histologic descriptions are reported in the literature and fewer reports describe the cytomorphology. Given the rarity of SMECE, data on the cytomorphologic and molecular features are limited. We report a case of a 53-year-old woman with a 5 cm left thyroid mass. Fine-needle aspiration (FNA) revealed atypia of undetermined significance and pathology of left thyroid lobectomy specimen showed SMECE. Additionally, a left pre-auricular lump was noted and FNA followed by left superficial parotidectomy showed basal cell adenoma. Next-generation sequencing showed point mutations in NTRK3 and NF1. Unlike salivary gland mucoepidermoid carcinoma, MAML2 translocations are not present in SMECE. Even though it is a rare entity, awareness of SMECE of the thyroid is important. In this case report we review the cytomorphologic, histologic, and molecular features.

Adenocarcinoma of the minor salivary gland with concurrent MAML2 and EWSR1 alterations

Salivary gland tumors are histologically diverse, and each entity has distinctive histopathological and molecular features. We report two cases of salivary gland tumors with unique histological and molecular findings, which have not been documented previously. The tumors were located in the base of the tongue in both patients. Most tumor cells were arranged in cords and nests, giving a trabecularlike appearance. Focally, glandular structures with intraluminal mucin and perivascular pseudorosette-like configurations were identified. Tumor cells had eosinophilic to clear cytoplasm, and showed mild nuclear atypia. They were positive for pancytokeratin and negative for S-100, p63, c-KIT, androgen receptor, and neuroendocrine markers. Multiple foci of capsular or lymphovascular invasion were identified, but the Ki-67 labeling index was low (< 5%). Fluorescence in situ hybridization revealed concurrent alterations of MAML2 and EWSR1 gene. Further investigations with a larger number of cases with similar histological and molecular features will accurately classify this tumor.

Sclerosing variant of mucoepidermoid carcinoma: a diagnostic challenge

The sclerosing variant of mucoepidermoid salivary gland carcinoma is extremely rare. It is nearly impossible to diagnose this condition preoperatively. We present a case of a 23-year-old woman with a 1-year history of left parotid enlargement with inconclusive fine-needle aspiration cytology results. MRI showed an irregular parotid mass, and subsequent partial parotidectomy confirmed the diagnosis. We discuss the diagnostic pitfalls of this condition and provide a review of the literature surrounding its pathogenesis and management.

Severe headache in a patient with meningioma showing extensive dural tail correlates with IgG4-positive plasma cells and eosinophils: A case report and review of literature

Background

Meningiomas originate from meningothelial cells of the arachnoid membrane. Few cases of meningioma with infiltration of inflammatory cells, such as lymphocytes and plasma cells, have been reported, and the mechanisms underlying meningioma-induced inflammatory reactions have not been fully elucidated.

Case Description

In this study, we report an extremely rare case of meningioma with infiltration of both IgG4-positive plasma cells and eosinophils showing extensive dural tail and reactive inflammation of the surrounding arachnoid tissue. The main clinical manifestation was a severe headache, which was improved by surgical excision of the tumor.

Conclusion

Only 8 cases of meningioma with IgG4-positive plasma cells have been reported, and only one case exhibited eosinophil infiltration. IgG4-related inflammatory response might mediate inflammation in surrounding tissue, resulting in thickening of the dura adjacent to a meningioma and severe headache. The mechanisms underlying inflammation by meningiomas require further investigation.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia distinct from the salivary type

We report three cases of thyroid sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE), which is an extremely rare variant of mucoepidermoid carcinoma (MEC). The aims of this report were to describe the clinicopathological findings, including results from immunohistochemical and fluorescence in situ hybridization analysis of thyroid SMECE, as well as to discuss the distinction between thyroid SMECE and its salivary counterpart. The cases included a 63-year-old female, a 44-year-old male, and a 66-year-old female, with all patients presenting with Hashimoto's thyroiditis. Nodal metastasis was not found in any of the three cases. Neither regional recurrences nor distant metastases were found in any patient during the follow-up, which was 20 years, 3 years, and 18 months, respectively. Histologically, tumors were composed of epidermoid carcinoma cells, intermediate type carcinoma cells, and goblet cell-type mucus-secreting carcinoma cells, with all tumors displaying a sclerotic stroma with eosinophilic and lymphocytic infiltration. The formation of eosinophilic abscess in the tumor nests that might be a novel characteristic finding of SMECE was observed. Immunohistochemically, the carcinoma cells were positive for cytokeratin 34βE12, TTF-1, and PAX8, but negative for thyroglobulin. In two cases, increased IgG4-positive plasma cells were observed. Mastermind-like transcriptional coactivator 2 (MAML2), according to fluorescence in situ hybridization, was intact in all cases. In conclusion, thyroid SMECE has favorable outcomes and seems to be genetically different from salivary MEC. This is the first report to describe the presence of increased IgG4-positive plasma cells in the stroma of SMECE.

Warthin-like papillary thyroid carcinoma with immunoglobulin G4-positive plasma cells possibly related to Hashimoto's thyroiditis

Hashimoto's thyroiditis with heavy lymphoplasmacytic infiltration is a common comorbidity of immunoglobulin G4 (IgG4)-related thyroiditis and Warthin-like papillary thyroid carcinoma (WL-PTC). We hypothesized that WL-PTC may have a strong association with IgG4-related thyroiditis. To validate this hypothesis, we clinically and immunohistochemically studied 17 WL-PTC cases. Fourteen patients (82.4%) had anti-thyroglobulin antibody and were confirmed to have Hashimoto's thyroiditis through microscopic analysis. Among them, five (29.4%) had disease consistent with IgG4-related thyroiditis but did not exhibit a "storiform" pattern or obliterative phlebitis. IgG4-related diseases were not found in other organs. No cases with serum IgG4 level of >135 mg/dL were noted. A total of 94.1% of WL-PTC cases had IgG4-positive plasma cells (⁺PCs) in the stroma, and cases with rich IgG4⁺PCs were more frequently associated with Hashimoto's thyroiditis than those with poor IgG4⁺PCs. In this study, all three cases without Hashimoto's thyroiditis had poor IgG4⁺PCs, and one of them did not exhibit IgG4⁺PCs in the stroma of WL-PTC and Hashimoto's thyroiditis. Nodal metastatic lesions were seen in eight cases, all of which were not WL-PTC. As such, we should consider that the Hashimoto's disease with rich IgG4⁺PCs seen in our cases is representative of non-IgG4-related disease and not IgG4-related disease involving multiple organs. This study is the first to demonstrate the presence of IgG4⁺PCs in the stroma of WL-PTC. We concluded that the appearance of IgG4⁺PCs in the stroma of WL-PTC may be related to Hashimoto's thyroiditis with rich IgG4⁺PC.

Sclerosing Mucoepidermoid Carcinoma of the Submandibular Gland Presenting as Chronic Sialadenitis: A Case Report and Review of Literature

Sclerosing mucoepidermoid carcinoma of the salivary gland (SMEC) is a rare subtype of mucoepidermoid carcinoma (MEC), first described in 1987 by Chan and Saw. As far as we are aware, only 30 cases have been published since then. Most cases were located in the parotid gland with some cases described in the submandibular and minor salivary glands. SMEC typically presents as a long-standing mass, with a non-specific enhancing appearance on imaging and is often non-diagnostic on fine needle aspiration, making pre-operative diagnosis very difficult. It is characterised by dense sclerosis within an otherwise typical MEC, frequently with lymphoid proliferation and eosinophils at the periphery. The histological diagnosis of SMEC can be challenging, as the sclerosis may obscure the other morphological features, which can lead to misdiagnosis. Grading can also be difficult, and the prognostic value of grading for SMEC remains unclear. Herein is described a new case of SMEC, presenting clinically as chronic sialadenitis in the left submandibular gland of a 41 year old male. A brief literature review and the issues surrounding diagnosis and grading are also discussed.

Sclerosing mucoepidermoid carcinoma of the sublingual gland

INTRODUCTION

Sclerosing mucoepidermoid carcinoma of the salivary gland is a rare subtype of mucoepidermoid carcinoma. The most common site of sclerosing mucoepidermoid carcinoma of the salivary glands is the parotid gland, followed by the submandibular gland, and the minor salivary glands.

OBSERVATION

Here we report the first case of sclerosing mucoepidermoid carcinoma of the sublingual gland.

DISCUSSION

Clinicians should consider sclerosing mucoepidermoid carcinoma in the differential diagnosis of salivary gland neoplasm. Surgical excision with clear margins seems to be a sufficient initial treatment option for sclerosing mucoepidermoid carcinoma of the salivary gland.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia: a clinicopathologic and molecular analysis of a distinct entity

Sclerosing mucoepidermoid carcinoma with eosinophilia is a rare thyroid neoplasm of uncertain pathogenesis that resembles salivary gland mucoepidermoid carcinoma. This multi-institutional study characterizes the clinicopathologic and molecular features of this tumor by utilizing next-generation sequencing to assess common mutations and gene fusions involved in thyroid carcinogenesis as well as fluorescence in-situ hybridization for MAML2 translocations typical of salivary gland mucoepidermoid carcinoma. Nine cases (6 females and 3 males, mean age: 59 years, range 30-77 years) were identified. All cases were comprised of nests and strands of tumor cells with both squamous and mucinous differentiation embedded in a fibrohyaline stroma with an inflammatory infiltrate replete with eosinophils. All cases were p63 positive, thyroglobulin negative and showed variable expression of TTF-1. All nine cases were negative for MAML2 rearrangements. Five cases successfully tested by next-generation sequencing (ThyroSeq v.2 assay) were negative for mutations and translocations commonly involved in thyroid carcinogenesis. NTRK1 showed overexpression but no evidence of translocation. On follow-up, one patient died of persistent disease, whereas one of four remaining patients with available follow-up (mean: 7.3 years, range 4-11 years) demonstrated recurrence at 4 years. Thus, we show that sclerosing mucoepidermoid carcinoma with eosinophilia appears molecularly and morphologically distinct from follicular and C-cell-derived thyroid tumors as well as from salivary gland mucoepidermoid carcinoma. The overall and recurrence-free survival for these patients may be lower than for other well-differentiated thyroid cancers.

The changing faces of IgG4-related disease: Clinical manifestations and pathogenesis

Since the earliest reports in 2001, immunoglobulin G4 (IgG4)-related disease has been defined as an autoimmune systemic disease characterized by the lymphoplasmacytic infiltration of affected tissues leading to fibrosis and obliterative phlebitis along with elevated serum IgG4 levels. Prior to this unifying hypothesis, a plethora of clinical manifestations were considered as separate entities despite the similar laboratory profile. The pathology can be observed in virtually all organs and may thus be a challenging diagnosis, especially when the adequate clinical suspicion is not present or when obtaining a tissue biopsy is not feasible. Nonetheless, the most frequently involved organs are the pancreas and exocrine glands but these may be spared. Immunosuppressants lead to a prompt clinical response in virtually all cases and prevent histological sequelae and, as a consequence, an early differential diagnosis from other conditions, particularly infections and cancer, as well as an early treatment should be pursued. We describe herein two cases in which atypical disease manifestations were observed, i.e., one with recurrent neck lymph node enlargement and proptosis, and one with jaundice. Our understanding of the pathogenesis of IgG4-related disease is largely incomplete but data support a significant role for Th2 cytokines with the contribution of innate immunity factors such as Toll-like receptors, macrophages and basophils. Further, macrophages activated by IL4 overexpress B cell activating factors and contribute to chronic inflammation and the development of fibrosis. We cannot rule out the possibility that the largely variable disease phenotypes reflect different pathogenetic mechanisms and the tissue microenvironment may then contribute to the organ involvement.

Local recurrence of sclerosing mucoepidermoid carcinoma with eosinophilia in the upper lip: a case report

INTRODUCTION

Sclerosing mucoepidermoid carcinoma with eosinophilia is a rare morphological variant of thyroid carcinoma associated with Hashimoto's disease. To date, only three such tumors have been reported in the minor salivary glands. We describe the first case, to the best of our knowledge, of recurrent sclerosing mucoepidermoid carcinoma with eosinophilia in the minor salivary glands of the upper lip.

CASE PRESENTATION

A 61-year-old Japanese man was referred to our hospital with a mass in his median upper lip of four years' duration. An examination of his median upper lip revealed a well-defined tumor measuring 9 × 12 mm in diameter, which was subsequently resected. Three years after the first surgery, the tumor recurred and was resected. Both tumors were confirmed by histopathology to be sclerosing mucoepidermoid carcinoma with eosinophilia. Neither recurrence nor metastasis was observed in three and a half years of follow-up after the second surgery.

CONCLUSION

Our findings indicate that sclerosing mucoepidermoid carcinoma with eosinophilia can originate in the minor salivary glands and may be clinically or pathologically misdiagnosed as other conditions.

Salivary mucoepidermoid carcinoma revisited

Clinicopathological features, prognosis and therapeutic strategies for mucoepidermoid carcinoma originating in salivary and salivary-type glands of the head and neck are reviewed. We emphasise histopathological aspects, appraise the value of histochemistry, electron microscopy, immunohistochemistry and cytophotometry, and discuss histogenesis and characteristic gene translocations. We additionally consider possible diagnostic difficulties, problems related to histological grading and accuracy of existing literature, and areas of controversy or uncertainty which may benefit from further investigations.