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.

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.

Expanding the histological spectrum of salivary gland neoplasms with HMGA2::WIF1 fusion emphasising their malignant potential: a report of eight cases.

AIMS: Recently, HMGA2::WIF1 fusion has been reported in pleomorphic adenoma (PAs) originating from the parotid gland with a characteristic canalicular adenoma (CAA)-like pattern. However, it is unclear whether HMGA2::WIF1 fusion may occur in salivary gland carcinoma or tumours originating from the minor salivary glands. We herein conducted a detailed clinicopathological review of eight salivary gland tumours harbouring HMGA2::WIF1 fusions. METHODS AND RESULTS: The reviewed diagnoses of salivary gland neoplasms with HMGA2::WIF1 fusion were PA (n = four), myoepithelioma (n = one), myoepithelial carcinoma ex PA (n = two) and high-grade carcinoma with basaloid features (n = one). Two tumours originated from the minor salivary glands. Six tumours (80%) contained areas reminiscent of CAA characterised by interconnected trabeculae/canaliculi of monotonous oncocytic or cuboidal tumour cells associated with a hypocellular, hyalinised to myxoid stroma. Areas typical of PA were seen in four (50%) cases. All tumours showed diffuse S100 and CK7 immunopositivity. Adverse events were detected in two cases, including local recurrence in a patient with PA, and local and distant recurrences and disease-related death in a patient with a high-grade carcinoma of the minor salivary gland of the buccal space, showing tumour necrosis and perineural invasion. CONCLUSION: Salivary gland neoplasms with HMGA2::WIF1 fusion are predominantly characterised by CAA/striated duct adenoma-like histology and a S100+/CK7+ immunoprofile. These tumours are not always benign, as among all reported cases approximately 20% showed malignancy (six of 28) and adverse outcome (three of 15), including recurrence, distant metastasis and disease-specific mortality.

Recent developments in the pathology of primary pulmonary salivary gland-type tumours.

Primary pulmonary salivary gland-type tumours are rare neoplasms that are thought to arise from seromucinous glands that are located in the submucosa of large airways. These neoplasms have clinical and pathologic features that are distinct from other pulmonary neoplasms. The majority of primary pulmonary salivary gland-type tumours are malignant, with the most common entities being mucoepidermoid carcinoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma. Less commonly seen are myoepithelial carcinoma, hyalinizing clear cell carcinoma, acinic cell carcinoma, secretory carcinoma, salivary duct carcinoma, intraductal carcinoma, and polymorphous adenocarcinoma. Benign salivary gland-type tumours of the lung include pleomorphic adenoma and sialadenoma papilliferum. Morphologic, immunophenotypic, and molecular features of these neoplasms are largely similar to salivary gland tumours elsewhere, and therefore the exclusion of metastatic disease requires clinical and radiologic correlation. However, the differential diagnostic considerations are different in the lung. The distinction of salivary gland-type tumours from their histologic mimics is important for both prognostication and treatment decisions. Overall, salivary gland type-tumours tend to have a more favourable outcome than other pulmonary carcinomas, although high-grade variants exist for many of these tumour types. Recent advances in our understanding of the spectrum of salivary gland-type tumours reported in the lung and their diversity of molecular and immunohistochemical features have helped to refine the classification of these tumours and have highlighted a few differences between salivary gland-type tumours of the lung and those primary to other sites.

Epithelial-Myoepithelial Carcinoma of Nasal Cavity at an Unusual Age: A Case Report and Review of Literature.

Introduction: Epithelial-myoepithelial carcinoma (EMC) was recognised as a distinct pathologic entity in World Health Organisation classification. It is an extremely rare low grade carcinoma of salivary gland, with characteristic biphasic tubular structures. It predominantly occurs in Parotid gland but can also be seen in nasopharynx, lacrimal gland, paranasal sinuses, larynx, lung. Nasal EMC (excluding the paranasal sinuses as primary tumour site) are very rare with only 13 cases reported till date. In this case report, we described a case of nasal EMC extending into nasopharynx, its clinical features and management. We have also done a literature review of all the relevant cases of nasal EMC. Material and Methods: We searched the PubMed database for articles between January 1950 and December 2022 for nasal EMC for this review. Results: We found 13 relevant case reports of nasal EMC and median age was 58 years with female preponderance. We found that our patient was the youngest to be reported till date. Two cases, including the current study, showed epicentre of the tumour in posterior nasal cavity, extending to choana and nasopharynx. Most common presentation was epistaxis, followed by nasal obstruction. Only 4 out of 14 cases had information on surgical margin status, out of which only one has positive surgical margin. Five patients (including the patient in the current study) received adjuvant radiotherapy; however 6 patients (42.8%) did not receive any adjuvant radiotherapy.

Myoepithelial carcinoma of soft tissues and bone.

AIM: Myoepithelial carcinoma occurs mainly in salivary glands but rarely can also occur in soft tissues or bone. In this paper, we evaluated the role of surgical margins, radiotherapy, and chemotherapy in myoepithelial carcinoma of soft tissue and bone (MC-SB) treated at our Institute. METHODS: Medical records of 33 patients presenting with MC-SB between 1998 and 2015 at our institution were retrospectively analysed, and diagnosis and treatment were studied. RESULTS: The median follow-up was 58.5 months. Twenty patients had tumours originating in soft tissues and 13 in bone. Eight patients (24.2%) had metastases at diagnosis, the remaining 25 had localised disease. Thirty-two underwent resection of the primary lesion. In 29 surgical margins were evaluated: wide in 28 with 10/28 who recurred (35.7%) and marginal resection in 1 who also recurred. Six patients received adjuvant radiotherapy. Metastases developed in 15/25 patients (60%) with localised disease at onset. Chemotherapy was administered in patients with metastatic advanced disease. Cisplatin+doxorubicin was administered in six patients as first-line chemotherapy with an objective response in 5/6 patients with a median 4-month duration. Five-year overall survival rate was 62.6% in patients with localised tumours and 12.5% in those metastatic at diagnosis. CONCLUSIONS: MC-SB showed a high incidence of local recurrences and metastases. Despite different chemotherapy regimens, the outcome remains poor in patients with metastatic disease. Due to the absence of a standard protocol, we encourage treatment by multidisciplinary teams in referral centres with renowned expertise.

HRAS mutation as a diagnostic molecular analysis for epithelial-myoepithelial carcinoma of the parotid gland: A case report.

HRAS mutations are frequent genetic alterations in epithelial-myoepithelial carcinoma, and they may be useful as ancillary molecular tests and predictive molecular tests for targeted therapy with tipifarnib.

EWSR1 rearranged primary renal myoepithelial carcinoma: a diagnostic conundrum.

Primary renal myoepithelial carcinoma is an exceedingly rare neoplasm with an aggressive phenotype and Ewing sarcoma breakpoint region 1 (EWSR1) rearrangement in a small fraction of cases. In addition to its rarity, the diagnosis can be challenging for the pathologist due to morphologic heterogeneity, particularly on the biopsy specimen. At times, immunohistochemistry may be indecisive; therefore, molecular studies should be undertaken for clinching the diagnosis. We aim to illustrate a case of primary myoepithelial carcinoma of the kidney with EWSR1-rearrangement in a 67-year-old male patient who presented with right supraclavicular mass, which was clinically diagnosed as carcinoma of an unknown primary. An elaborate immunohistochemical work-up aided by fluorescent in-situ hybridization allowed us to reach a conclusive diagnosis. This unusual case report advocates that one should be aware of the histological mimickers and begin with broad differential diagnoses alongside sporadic ones and then narrow them down with appropriate ancillary studies.

Repeated Surgery in a Case of Epithelial-Myoepithelial Carcinoma of the Parotid Gland that was Difficult to Distinguish from Pleomorphic Adenoma.

Epithelial-myoepithelial carcinoma (EMC) of the parotid gland is a comparatively rare tumor that accounts for less than 1% of all salivary gland tumors. A patient with EMC of the parotid gland that was initially diagnosed as pleomorphic adenoma and that recurred locally during the watchful waiting period but was controlled by surgery under local anesthesia is reported. An 80-year-old man had noticed a swelling in the left infra aural region. A left parotid gland tumor was suspected, and he was referred to our department. Magnetic resonance imaging (MRI) and fine-needle aspiration cytology findings were suggestive of pleomorphic adenoma of the superficial lobe of the parotid gland, and this was therefore resected under general anesthesia. Postoperative histopathological examination, immunostaining, and genetic tests resulted in a diagnosis of EMC. Postoperative pathological review showed that part of the resection margin was positive. The possibility of recurrence was explained to the patient, and additional treatment was recommended, but since the patient did not desire this, a policy of watchful waiting was adopted. Signs of cutaneous metastasis in the left infra aural region were detected at 13 months postoperatively, and this metastasis was excised under local anesthesia. The resection margin was negative, and the patient's course remains uneventful. EMC is classified as a low-grade malignant tumor, but it requires stringent monitoring because of its frequent local recurrence. Since local control can usually be achieved by surgical treatment alone, and postoperative adjuvant therapy may not necessarily warranted.

Long-Term Disease Control of Locally Invasive Epithelial-Myoepithelial Carcinoma of Parapharyngeal Salivary Glands With Definitive Radiotherapy.

Epithelial-myoepithelial carcinoma (EMC) is a rare clinical entity that affects glandular tissues, most commonly salivary glands. EMC of parapharyngeal space is exceedingly rare. Surgery is the mainstay of treatment with or without chemotherapy, radiotherapy, or both. Due to the rarity of the disease, select cases where surgery is not possible present a management conundrum. We present a case of locally advanced, stage IVa EMC of parapharyngeal space that was treated with upfront definitive radiotherapy. Radiotherapy treatment alone led to long-term disease control in both clinical and radiological follow-ups. The patient was followed for more than eight years posttreatment with no disease recurrence, enjoying the normal activities of life with no late toxicities including xerostomia. This case report highlights the role of radiotherapy in the management of such patients, and more studies are required in this context for surgical candidates with positive disease margins.

Epithelial-myoepithelial carcinoma with multiple recurrences: An unusual presentation.

Epithelial-myoepithelial carcinoma (EMC) is a type of malignant salivary gland tumors that is extremely rare. EMC primarily affects major salivary glands, particularly the parotid gland, but minorsalivary glands are also affected. It contributes less than 0.5-1% of all salivary gland neoplasms. Multiple recurrences are relatively rare with EMC. There have been very few reports of multiplerecurrences in the literature. Biphasic tubular structures composed of externalclear cells and inner ductal cells are the distinguishing histopathological feature. However, histological variation is prevalent, making a precise diagnosis challenging. We present a case of EMC that had multiple recurrences during a six-year period.

[Giant myoepithelial carcinoma of the nuchal region: a case report and literature review].

Myoepithelioma, also known as malignant myoepithelioma, is a rare malignant tumor originating from myoepithelial cell. This article reports a patient with a huge tumor in the neck and left elbow who underwent fine needle aspiration under local anesthesia. The pathological diagnosis was a myoepithelioma. Under general anesthesia, giant tumors in the lower neck, posterior cranial fossa, neck, and left elbow were removed, and postoperative pathology showed that they were all myoepithelial tumors. Immunohistochemistry showed AE1/AE3 (+), P63 (+), CK7 (+), CK5 (+), and CD138 (+). The clinical characteristics and diagnosis and treatment process of this case are reported and relevant literature is reviewed.

Epithelial-Myoepithelial Carcinoma of the Nasal Cavity: A Case Report.

Epithelial-myoepithelial carcinoma is an extremely rare tumor of the nasal cavity. We present a case involving a 67-year-old female with symptoms of nasal obstruction and recurrent epistaxis. An investigation with endoscopy and CT was performed. The patient underwent endoscopic surgical resection. Microscopic positive margins were present after extensive resection. The patient underwent radiotherapy utilizing proton therapy and has been disease free for 6 months at follow-up.

Metastatic Myoepithelial Carcinoma Ex Pleomorphic Adenoma of the Sublingual Salivary Gland.

Myoepithelial carcinoma ex pleomorphic adenoma is a very rare malignant neoplasm of the salivary gland. Owing to its rarity, its clinical features and treatment are not well characterized. We describe a case of a patient who was referred to our department with a six-month history of a bulge on the right side of the floor of the mouth and a submandibular mass with progressive enlargement. The mass was resected, and an elective level I neck dissection was performed. Histological examination revealed myoepithelial carcinoma ex pleomorphic adenoma of the sublingual salivary gland. Thoracic computed tomography and biopsy revealed lung metastases. The patient died two years after the diagnosis.

Epithelial Myoepithelial Carcinoma Masquerading as Simple Parotid Cyst in a Middle Aged Male.

Epithelial-Myoepithelial Carcinoma (EMC) is a very rarely seen biphasic tumour typically seen in older females and constitutes 0.5-1% of all salivary gland neoplasms. The parotid gland is most often involved and occasionally there may be involvement of submandibular and minor salivary glands. Clinical picture often reveals benign nature of the disease. Computed tomography (CT) and magnetic resonance appearances are non-specific and the cytological diagnosis may be challenging, thus more accurate diagnosis can only be made by histological and immunohistochemical study. There is no consensus regarding the optimal treatment of this neoplasm, largely due to its rarity. Wide surgical excision with a clear margin is the treatment of choice because of the tumour's tendency to infiltrate locally. Adjuvant radiotherapy is often required in cases of large primary tumours and positive surgical margins. The tumour may commonly recur locally after resection in 30-50% of cases. We herein present an unusual case of a 46-year-old male who presented with cystic swelling of left parotid gland and diagnosed as EMC on histopathology and immunohistochemical examination. The patient was treated with surgical resection followed by post-operative radiotherapy.

Cytopathology of salivary gland myoepithelial carcinoma: A study of 13 cases and review of the literature.

INTRODUCTION: Myoepithelial carcinoma (MECA) is an infrequently recognized salivary gland (SG) neoplasm that commonly develops within a preexisting pleomorphic adenoma (MECA ex PA). Fine-needle aspiration (FNA) biopsy reports of this neoplasm are largely restricted to small series and single case reports. METHODS: Our cytopathology files were searched for examples of SG MECA/MECA ex PA having confirmatory histopathologic verification. Conventional FNA biopsy smears were performed, and exfoliative specimens processed using standard techniques. RESULTS: Thirteen cases from 9 patients (M:F = 3.5:1; age range: 36 to 95 years, mean age = 60 years) met inclusion criteria. FNA biopsy sites included parotid gland (4), trunk (2), scalp (2), and neck (2). Exfoliative specimens included pleural fluid (1), bronchial brushing (1), and bronchoalveolar lavage (1). Most cases were metastatic deposits (8; 62%), 4 were primary neoplasms, and 1 a local recurrence. FNA diagnoses were MECA ex PA (6; 46%), myoepithelial neoplasm (2), PA (2), basaloid neoplasm (1), atypical myoepithelial cells (1), and myxoma (1). Ancillary testing in 2 cases showed positive staining for myoepithelial markers. Cytologic features were that of a low-grade neoplasm composed principally of epithelioid/polygonal cells exhibiting minimal if any cytologic atypia. Myxoid and chondromyxoid stroma was often the dominant feature in MECA ex PA aspirates. CONCLUSION: In the primary setting, a cytologic diagnosis of MECA/MECA ex PA is extremely challenging if at all possible. Due to overwhelming amounts of stroma, the diagnosis may be challenging in some cases of metastatic MECA ex PA.

An intraosseous myoepithelial carcinoma with a EWSR1::PBX3 fusion.

Herein we report a case of an intraosseous myoepithelial carcinoma harboring a EWSR1::PBX3 fusion gene. The patient was a 64-year-old male found to have a 7 cm destructive lesion in the distal ulna with an extraosseous soft tissue component. Microscopic examination of the resected tumor showed a spindle-cell lesion within a sclerotic stroma and intravascular tumor emboli. At higher power the tumor cells showed moderate nuclear atypia with a high mitotic count (20 per mm2 ). Immunohistochemistry revealed diffuse EMA positivity and focal pancytokeratin (AE1/AE3) and S100 expression, consistent with myoepithelial differentiation. NGS using the Oncomine Childhood Cancer Assay (Thermo Fisher Scientific, Inc.) revealed a EWSR1-PBX3 fusion and ABL amplification. The patient subsequently developed local recurrence as well as distant lymph node, lung and vertebral metastases; he is currently awaiting systemic treatment in the context of a clinical trial. In this report, we present a rare case of a skeletal myoepithelial tumor harboring a EWSR1::PBX3 fusion with demonstrated histological and clinical features of malignancy.

Epithelial-myoepithelial carcinoma of retro-molar trigone: Unveiling the mystery of rare diagnosis.

Epithelial-myoepithelial carcinoma (EMC), a low-grade malignant neoplasm of glandular origin, most commonly involves major and occasionally minor salivary glands. It is rare in minor salivary glands such as hard and soft palate, buccal mucosa, tongue, and so on, frequently affecting geriatric females. EMC comprises diverse histo-pathologic features of an epithelial, myoepithelial de-lineating biphasic pattern along with clear cells, sometimes oncocytic differentiation. Aberrant histo-pathologic features in EMC need judicious discrimination from alike entities, which facilitates appropriate surgical management. Here, we present an unusual case report of EMC in the left retro-molar trigone region in a 60-year-old male patient, the complete diagnosis of which was based on clinical, radiological, histo-pathological, and immuno-histo-chemical features.

MYB RNA detection by in situ hybridisation has high sensitivity and specificity for the diagnosis of adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is one of the most common primary salivary gland cancers. ACC has several benign and malignant mimics amongst salivary gland neoplasms. An accurate diagnosis of ACC is essential for optimal management of the patients and their follow-up. Upregulation of MYB has been described in 85-90% of ACC, but not in other salivary gland neoplasms. In ACC, MYB upregulation can occur as a result of a genetic rearrangement t(6;9) (q22-23;p23-24), MYB copy number variation (CNV), or enhancer hijacking of MYB. All mechanisms of MYB upregulation result in increased RNA transcription that can be detected using RNA in situ hybridisation (ISH) methods. In this study, utilising 138 primary salivary gland neoplasms including 78 ACC, we evaluate the diagnostic utility of MYB RNA ISH for distinguishing ACC from other primary salivary gland neoplasms with a prominent cribriform architecture including pleomorphic adenoma, basal cell adenoma, basal cell adenocarcinoma, epithelial myoepithelial carcinoma, and polymorphous adenocarcinoma. Fluorescent in situ hybridisation and next generation sequencing were also performed to evaluate the sensitivity and specificity of RNA ISH for detecting increased MYB RNA when MYB gene alterations were present. Detection of MYB RNA has 92.3% sensitivity and 98.2% specificity for a diagnosis of ACC amongst salivary gland neoplasms. The sensitivity of MYB RNA detection by ISH (92.3%) is significantly higher than that of the FISH MYB break-apart probe (42%) for ACC. Next generation sequencing did not demonstrate MYB alterations in cases that lacked MYB RNA overexpression indicating high sensitivity of MYB RNA ISH for detecting MYB gene alterations. The possibility that the sensitivity may be higher in clinical practice with contemporary samples as compared with older retrospective tissue samples with RNA degradation is not entirely excluded. In addition to the high sensitivity and specificity, MYB RNA testing can be performed using standard IHC platforms and protocols and evaluated using brightfield microscopy making it a time and cost-efficient diagnostic tool in routine clinical practice.