Establishment of experimental salivary gland cancer models using organoid culture and patient-derived xenografting

Purpose

Depending on its histological subtype, salivary gland carcinoma (SGC) may have a poor prognosis. Due to the scarcity of preclinical experimental models, its molecular biology has so far remained largely unknown, hampering the development of new treatment modalities for patients with these malignancies. The aim of this study was to generate experimental human SGC models of multiple histological subtypes using patient-derived xenograft (PDX) and organoid culture techniques.

Methods

Tumor specimens from surgically resected SGCs were processed for the preparation of PDXs and patient-derived organoids (PDOs). Specimens from SGC PDXs were also processed for PDX-derived organoid (PDXO) generation. In vivo tumorigenicity was assessed using orthotopic transplantation of SGC organoids. The pathological characteristics of each model were compared to those of the original tumors using immunohistochemistry. RNA-seq was used to analyze the genetic traits of our models.

Results

Three series of PDOs, PDXs and PDXOs of salivary duct carcinomas, one series of PDOs, PDXs and PDXOs of mucoepidermoid carcinomas and PDXs of myoepithelial carcinomas were successfully generated. We found that PDXs and orthotopic transplants from PDOs/PDXOs showed similar histological features as the original tumors. Our models also retained their genetic traits, i.e., transcription profiles, genomic variants and fusion genes of the corresponding histological subtypes.

Conclusion

We report the generation of SGC PDOs, PDXs and PDXOs of multiple histological subtypes, recapitulating the histological and genetical characteristics of the original tumors. These experimental SGC models may serve as a useful resource for the development of novel therapeutic strategies and for investigating the molecular mechanisms underlying the development of these malignancies.

Nodal Metastases in Pediatric and Adult Acinic Cell Carcinoma of the Major Salivary Glands

OBJECTIVE

Acinic cell carcinoma (AciCC) is a rare, usually low-grade salivary malignancy. Evidence on rates of lymph node metastases (LNMs) is limited in pediatric patients and varies significantly (4%-45%) in adults. We set out to determine and compare rates of LNMs in pediatric and adult AciCC and to analyze their impact on survival, using the National Cancer Database.

STUDY DESIGN

Historical cohort study.

SETTING

National Cancer Database.

METHODS

All AciCCs of the major salivary glands with complete clinical and pathologic nodal staging were selected between 2010 and 2016. Patient demographics, tumor characteristics, treatment, and survival were analyzed. Univariable and multivariable regression were performed to determine factors associated with LNMs and survival.

RESULTS

We identified 57 (4.6%) pediatric patients (<18 years) and 1192 (95.4%) adults with AciCC. Clinical LNMs were rare in pediatric patients (n < 10) and adults (n = 88, 7.4%). Occult LNMs were uncommon in pediatric patients (n < 5) and adults (n = 41, 4.6%). Three-year overall survival for pediatric patients was 97.8%. Adults with LNM had worse 3-year overall survival than those without (66.0% vs 96.3%, P < .001). In multivariable regression, high-grade disease (hazard ratio, 10.15 [95% CI, 5.60-18.80]; P < .001) and T3-T4 tumors (hazard ratio, 2.80 [95% CI, 1.56-4.97]; P < .001) were associated with LNM in adult patients.

CONCLUSION

LNMs in AciCC of the major salivary glands are rare in children and adults. However, high-grade and T3-T4 tumors are associated with an increased risk of LNM. LNM is associated with worse survival.

Survival Outcome of Salivary Gland Carcinoma: A 50-Year Retrospective Study With Long-Term Follow-up

PURPOSE

Salivary gland carcinomas (SGCs) can be classified into more than 20 subtypes with various clinical behaviors. The present study aimed to analyze the clinical and pathological features of SGCs and evaluate their long-term prognosis.

METHODS

A retrospective cohort study was performed. This study investigated cases of histologically confirmed SGC at the authors' institution from January 1963 to December 2014. Data on sex, age, site, histopathological diagnosis, tumor-node-metastasis classification, postoperative radiotherapy and/or chemotherapy, local and regional recurrence, and distant metastasis (DM) were collected as covariates. The overall survival (OS) rate was analyzed as the outcome. Kaplan-Meier survival analysis and Cox multivariate analysis were used for survival analysis. The cohort was divided into 2 groups-before and after 1989. The clinicopathological characteristics of the 2 groups were compared using the χ² test.

RESULTS

The cohort included 1,637 patients who met the admission criteria and had a male-to-female ratio of 0.9:1. The median age was 47 years (range, 8 months to 86 years). The median follow-up time was 54 months (range, 1-432 months). The majority of the tumors occurred in the parotid gland (35.3%), followed by the palate gland (25.2%). Adenoid cystic carcinoma was the most common tumor type (34.3%), and mucoepidermoid carcinoma (29%) was the second most common type. In the 1,637 patients, the neck lymph node metastasis rate was 8.7% at the first surgery, and the overall DM rate was 14.1%. The 5-, 10-, and 15-year OS rates of the 1,637 cases were 93.1%, 87.2%, and 79.3%, respectively. Comparative analysis before and after 1989 showed statistically significant differences in sex, site, histologic subtype, T classification, local and regional recurrence rate, and radiotherapy (P < .05), while no significant differences were found in age, N classification, M staging, DM, or chemotherapy.

CONCLUSIONS

The OS rates of SGC have improved significantly over the past 30 years. This is attributable to an increase in the proportion of patients diagnosed at the early stage and receiving radiotherapy, as this has led to a reduction in the local and regional recurrence rate and, consequently, an improvement in the survival rates.

Secretory carcinoma of the sinonasal cavity and pharynx: A retrospective analysis of four cases and literature review

Secretory carcinoma (SC) is a recently recognized type of salivary gland tumor characterized by t(12;15) (p13;q25) translocation resulting in an ETV6-NTRK3 gene fusion. Most SCs are located in a main salivary gland, and primary sinonasal secretary carcinoma is rare. We describe three cases of primary SC in the sinonasal cavity with high-grade transformation (HGT) in one case, and the first case in the pharynx. All tumors comprised slightly atypical cells with solid, tubular, microcystic growth patterns. The case with HGT included two components with distinct sharp boundaries and comedo necrosis, high mitotic figures and obvious cellular atypia. Tumor cells were positive for vimentin, S100, and Gata-3 and negative for p63 and DOG-1. Three cases showed nuclear staining of pan-TRK and one showed cytoplasmic staining. All cases harbored ETV6 gene rearrangement, and ETV6-NTRK3 gene fusion was detected in three cases. Most patients were treated with radical resection and adjuvant therapy. After excision, all remained tumor-free for 65-164 months (medium 98.5 months). SC in the sinonasal cavity and pharynx is a low-grade malignant tumor with histologic features overlapping those of other salivary gland tumors. Immunohistochemical analysis and fluorescence in situ hybridization are useful techniques for its differential diagnosis.

Bronchial salivary gland–type intraductal carcinoma with KIAA1217::RET gene fusion composed of intercalated and oncocytic components

Salivary gland-type intraductal carcinoma (IC) is a rare malignant salivary gland neoplasm. Primary salivary gland-type IC has never been described in the lung. Herein, we present a primary pulmonary IC in a 63-year-old woman. The tumor originated in the bronchus wall of the right middle lobe. The tumor consisted of two histological types, intercalated component and oncocytic component. The intercalated component showed tubular/cystic pattern composed of column to cube-shaped cells and scattered mucous cells. The oncocytic component showed solid nests composed of large cells with abundant eosinophilic granular cytoplasm. Immunohistochemically, both histological components were positive for cytokeratin 7 (CK7), S-100 protein, SOX10, and mammaglobin. The rimming myoepithelial cells were highlighted by p63 and smooth muscle actin (SMA). The tumor cells were negative for androgen receptor (AR), HER-2, Dog-1, TTF-1, napsin A, GCDFP-15, and GATA3. In the present case, we detected KIAA1217::RET fusion via DNA-based next-generation sequencing (NGS) and RT-PCR, which established the diagnosis of IC at a molecular level. The present case expands the categories of bronchopulmonary salivary gland-type tumors.

[Clinicopathological observation of 10 cases of salivary secretory carcinoma]

Objective: To investigate the clinical and pathological features of salivary secretory carcinoma (SSC). Methods: Ten cases of SSC confirmed in the Department of Pathology,Capital Medical University School of Stomatology from January 2014 to December 2021 were retrospectively included, including 5 males and 5 females, with a median age of 46.5 years. The microscopic morphology, immunophenotype, special staining and clinical follow-up of 10 cases of salivary secretory carcinoma were observed. Ten patients were tested with S-100, vimentin, mammaglobin, Dog-1, p63 and Ki-67, 9 cases with cytokeratin (CK) 8/18, 8 with CK7, 6 with calponin, 5 with smooth muscle actin (SMA) and GCDFP15, 4 with CK5/6 and 1 with SOX10. The ETV6-NTRK3 fusion gene was detected by fluorescence in situ hybridization. Results: Seven of the 10 SSC were located in the parotid gland and 3 were located in the cheeks. Histomorphology showed solid, papillary-cystic, follicular, microcystic, and macrocystic types. In 7 cases, tumor cells were dominated by single arrangement type, while certain mixed arrangements existed in some areas. The cytoplasm of the tumor cells was rich in eosinophilic, fine granular or vacuolar shapes, and clear cytoplasm was seen in 2 cases. The nuclei were mostly oval-shaped vesicular nuclei, with nucleoli in the center. Immunohistochemistry showed CK7 (8/8) positive, CK8/18 (9/9) positive, S-100 (10/10) positive, vimentin (5/10) positive, (4/10) partially positive and (1/10) less partially positive, mammaglobin (7/10) positive, (1/10) partially positive and (2/10) some individual cells positive, Dog-1 (10/10) negative, CK5/6 (4/4) negative, p63 (7/10) negative and (3/10) partially positive, SMA (5/5) negative, calponin (6/6) negative, and Ki-67 index was 5%-20%. Secretions of 5 cases showed periodic acid-Schiff (PAS) and PAS with diastase (PAS-D) staining positive. All 10 cases showed ETV6-NTRK3 fusion positive. Six cases were successfully followed up for 32-91 months, of which 2 cases recurred after 28 and 74 months and underwent surgical resection again. All cases followed up are alive and disease-free. Conclusions: The salivary secretory carcinoma is a rare low-grade malignant tumor. In certain cases, morphology is atypical and mammaglobin is immunohistochemically positive in only individual tumor cells. Therefore, the diagnosis should be supported with morphology, immunohistochemical staining, and molecular feature preferably.

[Changes of the World Health Organization 2022 classification (5th edition) of salivary glands tumors]

Pathological diagnosis of salivary gland tumors is one of the most challenging areas in all head and neck surgical pathology. The classification of salivary gland tumors was updated in the 5th edition of the World Health Organization Classification of Head and Neck Tumours, most of which were based on their molecular pathological characteristerics. This new classification features a description of several new entitiesamong benign and malignant neoplasms, salivary gland tumors with updated naming or diagnostic criteria, and lesions deleted from this section, etc.This present review focuses on the updates and changes in the new classification of salivary gland tumors, and provides some reference for head and neck surgeons and pathologists.

Microsecretory Adenocarcinoma of the Ear Canal: Novel Cutaneous Analog of a Salivary Gland Neoplasm

ABSTRACT

Microsecretory adenocarcinoma (MSA) of the salivary gland is a new entity recently added to the World Health Organization Classification of Head and Neck Tumors. This tumor is characterized by a recurrent MEF2C-SS18 translocation. We present a nodular tumor confined to the dermis of the ear canal of a 44-year-old patient, which demonstrated classic histopathologic features and molecular alteration of MSA. Specifically, the tumor was composed of numerous tubules and microcysts filled with abundant basophilic mucinous secretion and associated with a fibromyxoid stroma. The tumor cells were diffusely positive for CK7 and SOX10 and variably positive for S100 and p63. Breakapart fluorescence in situ hybridization for SS18 confirmed rearrangement of this gene. Together, these findings support a primary cutaneous MSA, presumably arising from ceruminous glands of the ear canal. Based on current knowledge of its salivary gland counterpart, cutaneous MSA is expected to be locally invasive but unlikely to recur or metastasize on complete excision.

Metastatic salivary gland neoplasms to pleural effusion: diagnostic challenges and prognostic significance in a series with 9 patients

INTRODUCTION

Pleural effusions can present a diagnostic challenge as they are not always caused by malignancy in patients with a history of typical visceral primaries.

MATERIAL AND METHODS

At 2 major academic medical centers, we have identified several cases in which salivary gland neoplasms metastasized to pleural effusions in patients who have been aggressively managed with various treatment modalities including chemotherapy, radiation, and/or surgical excision.

RESULTS

Herein, we present a range of primary salivary gland tumors that metastasized to serous effusions and characterize their cytomorphology, immunoprofiles, and clinical courses. Our case series shows that many tumor types metastasize to pleural effusions and they present unique diagnostic challenges in each case. We found that metastasis of a salivary gland neoplasm to a pleural effusion is a late-stage event and is often associated with poor prognosis.

CONCLUSIONS

This series serves as a resource to demonstrate the cytomorphologic and immunohistochemical features of malignant pleural effusions due to salivary gland neoplasms and draws attention to poor prognosis in cases of salivary duct carcinoma, mucoepidermoid carcinoma and adenoid cystic carcinoma.

CD24-gold nanocomposite as promising and sensitive biomarker for cancer stem cells in salivary gland tumors

Cancer stem cells are highly tumorigenic cells in the majority of the tumor that are responsible for the initiation, rapid growth, invasion, metastasis, and therapeutic resistance associated with various human cancers. The aim of this project is to assess a diagnostic and prognostic biomarker for the detection of cancer stem cells in salivary gland tumors using gold nanoparticles that are synthesized and conjugated to CD24 primer to form a CD24-Gold Nanocomposite. Sixty cases were included (29 pleomorphic adenoma, 19 carcinoma ex pleomorphic adenoma, and 12 normal controls). Alterations in biomarker expression between studied groups were analyzed and correlated with clinicopathological characteristics using Fisher's exact and Chi-square tests. ROC and Kaplan-Meier curves were used to validate diagnostic and prognostic values, respectively. This study confirms that CD24-Gold Nanocomposite served as a promising and highly sensitive biomarker in salivary gland tumor diagnosis and prognosis prediction.

Secretory carcinoma of the salivary gland: a multi-institutional clinicopathologic study of 90 cases with emphasis on grading and prognostic factors

Secretory carcinoma (SC) is a rare form of salivary carcinoma that was first described in 2010 and is characterized by ETV6::NTRK3 fusion in most cases. In this large retrospective study, we aimed to identify adverse clinicopathologic factors and propose a prognostically relevant grading scheme for SC.

METHODS

A detailed clinicopathologic review was conducted on 90 SCs from the major and minor salivary glands.

RESULTS

The median age at presentation was 50 years (range: 7-93). Sixty-nine (77%) tumours originated from major salivary glands, whereas the remaining 21 involved minor salivary glands.Six cases (7%) had cervical nodal metastasis. Only lymphovascular invasion (LVI) was associated with a risk of nodal metastasis (P < 0.05). The 5-year disease-specific survival and disease-free survival (DFS) were 98% and 87%, respectively. On univariate survival analysis, adverse prognostic factors associated with decreased DFS included minor salivary gland origin, atypical mitosis, high mitotic index, high-grade transformation (HGT), necrosis, nuclear pleomorphism, infiltrative tumour border, fibrosis at the invasive front, LVI, positive margin, and advanced pT stage (P < 0.05). When adjusted for pT stage and margin status, mitotic index, LVI, nuclear pleomorphism, and HGT remained as independent prognostic factors.

CONCLUSION

We therefore propose a two-tiered grading system for SC. The low-grade SC is defined as those with <5 mitoses /10 high-power fields and no tumour necrosis, and high-grade SC as those with ≥5 mitoses /10 high-power fields and/or necrosis. This proposed grading system can be useful to risk stratify patients with SC for appropriate clinical management.

NOR-1 (NR4A3) immunostaining on cytologic preparations for the preoperative diagnosis of acinic cell carcinoma of the salivary gland

INTRODUCTION

Acinic cell carcinoma of the salivary gland (ACC-SG) is characterized by recurrent rearrangements in the nuclear receptor subfamily 4 group A member 3 (NR4A3). Immunostaining using an antibody targeting this rearrangement, neuron-derived orphan receptor 1 (NOR-1), has been recently studied on surgical specimens and cell block material of fine-needle aspirates for the diagnosis of ACC-SG. Our goal was to evaluate whether NOR-1 immunostaining could reliably be performed on destained cytologic preparations.

MATERIALS AND METHODS

This was a retrospective multi-institutional study. Immunostaining with the NOR-1 antibody (sc-393902 [H-7], Santa Cruz Biotechnology Inc.) was performed at a titer of 1:30 on destained cytologic preparations. ACC-SG cases (n = 17) were represented by twelve cases with alcohol-fixed preparations (n = 12), including direct smears and SurePath preparations, as well as 5 cases with air-dried preparations (n = 5). These were compared to 27 mimicker lesions (n = 27): normal acini (4), chronic sialadenitis (3), oncocytoma (2), pleomorphic adenoma (6), Warthin tumor (8), mucoepidermoid carcinoma (1), secretory carcinoma (2), and salivary duct carcinoma (1).

RESULTS

The positivity of NOR-1 in ACC-SG cases was 100% on destained alcohol-fixed preparations (12/12) and 60% on air-dried preparations (3/5). All 27 mimicker lesions were negative for NOR-1 (0/27). Evaluation of 2 ACC-SG cases with both types of cytologic preparations showed that NOR-1 was positive on the alcohol-fixed slides but negative on the air-dried slides.

CONCLUSIONS

NOR-1 immunostaining can reliably be performed on alcohol-fixed direct smears and liquid-based preparations for the diagnosis of ACC-SG. Air-dried preparations show a lower positivity rate and may be less suitable for diagnostic immunostaining.

A CYTOLOGICAL AND HISTOPATHOLOGICAL CORRELATIVE STUDY ON NEOPLASTIC LESIONS WITH MILAN SYSTEM FOR REPORTING SALIVARY GLAND CYTOPATHOLOGY

BACKGROUND

Salivary gland tumors are rare. Nevertheless, the accurate preoperative diagnosis of the malignant potential of the lesion is essential for appropriate patient management. The recently published Milan system for reporting salivary gland cytology (MSRSGC) is an effort to provide better communication regarding the nature of lesions to clinicians. Aim: To evaluate the diagnostic utility of fine-needle aspiration cytology (FNAC) of neoplastic salivary gland lesions and the MSRSGC applicability in risk stratification.

MATERIALS AND METHODS

This was a retrospective study of the cytological and histopathological correlation between neoplastic lesions of salivary gland lesions conducted over four years (August 2010 - September 2014) in two tertiary care hospitals. There were 66 cases of FNAC of salivary gland neoplasms. The sensitivity, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy of FNAC were analyzed. The risk of malignancy for MSRSGC was calculated.

RESULTS

The overall diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values were 93.94; 95.5; 99.8; 96.8, and 98.7%, respectively. By correlating the cytological diagnosis of benign neoplasm with histopathological diagnosis, the risk of malignancy was 0% and risk of neoplasm was 100%. For cases in the category suspicious of malignancy, risk of neoplasm was 100% and risk of malignancy was 85%.

CONCLUSION

The present study demonstrated that this salivary gland cytology reporting system was useful in classifying the lesions in well-delineated categories with ease. MSRSGC system of standardized reporting is helpful for guiding clinicians in appropriate management of the patient. However, many multicenter studies with large sample sizes and long-term follow-up are needed along with wide propagation of its standardized reporting format to be adopted universally.

MR Imaging Findings of Carcinoma Ex Pleomorphic Adenoma Related to Extracapsular Invasion and Prognosis

BACKGROUND AND PURPOSE

MR imaging can reflect the pathologic progression of carcinoma ex pleomorphic adenoma (CXPA). This study aimed to identify the imaging findings related to extracapsular invasion of CXPA. Additionally, the pathologic background of these findings was investigated.

MATERIALS AND METHODS

This retrospective study included 37 patients with histologically confirmed CXPA. Three radiologists independently evaluated whether the CXPA showed the following characteristic MR imaging findings: border, capsule, the corona sign on fat-saturated T2WI and contrast-enhanced fat-saturated T1WI, and the black ring sign. The corona sign appeared larger on fat-saturated and/or contrast-enhanced fat-saturated T1WI than on T1WI. The black ring sign was defined as an intratumoral nodule with a thick low-intensity rim on T2WI. Interreader agreement of the visual assessment was performed using κ analysis, and MR imaging and histopathologic findings were also correlated. Kaplan-Meier survival and the log-rank test were used to estimate the 3-year disease-free survival.

RESULTS

MR imaging findings, especially peritumoral findings, showed a significant difference between invasive and noninvasive CXPA. The reliability was poor for the border and capsule. In contrast, it was good for the corona sign on fat-saturated and contrast-enhanced fat-saturated T1WI and the black ring sign. Pathologically, the corona sign reflected the invasiveness of the tumor and inflammatory cells, while the black ring sign reflected hyalinization or fibrosis. The corona sign also showed a significant difference in the 3-year disease-free survival.

CONCLUSIONS

MR imaging findings, including the corona and black ring signs, reliably differentiated invasive and noninvasive CXPA. The corona sign can be used as a prognostic factor for CXPA.

Recurrent pleomorphic adenoma: unusual cause of isolated sphenoid sinus lesion

Pleomorphic adenoma is the most common benign salivary gland tumour of the head and neck region, most commonly seen in parotid glands. These may arise also from minor salivary glands of the upper aerodigestive tract comprises the upper lip, cheek, floor of the mouth and rarely from mucoserous glands in the nasal cavity and paranasal sinuses. A middle-aged man, who had undergone surgery for a nasal mass 14 years ago, presented with headache and visual complaints from a recurrent mass originating from the sphenoid sinus. Isolated sphenoid sinus space-occupying lesions have always been a diagnostic challenge. The mass was biopsied and diagnosed as pleomorphic adenoma on histopathology, and then excised endoscopically. Early and accurate diagnosis on a biopsy may result in complete excision of the tumour and prevent recurrence. The endoscopic route is preferred for surgical excision and the patient should be followed up clinically and radiologically to detect early recurrence.

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC), the same or different entities?

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC) have overlapping histopathological appearances and sites of occurrence, which may cause diagnostic difficulty impacting subsequent treatment. We conducted a systematic review of the scientific literature to determine whether molecular alterations were sufficiently different in MEC and ASC to aid in classifying the two entities. We searched Medline, Embase and Web of Science for studies reporting molecular determinations of ASC and/or MEC and screened retrieved records for eligibility. Two independent researchers reviewed included studies, assessed methodological quality and extracted data. Of 8623 identified records, 128 articles were included for analysis: 5 which compared the two tumors in the same investigation using the same methods and 123 which examined the tumors separately. All articles, except one were case series of moderate to poor methodological quality. The 5 publications examining both tumors showed that 52/88 (59%) MEC and 0% of 110 ASC had rearrangement of the MAML2 gene as detected by FISH and/or RT-PCR, but did not investigate other genes. In the entire series MEC had MAML2 gene rearrangement in 1337/2009 (66.6%) of tumors studied. The articles examining tumors separately found that MEC had mutations in EGFR (11/329 cases, 3.3%), KRAS (11/266, 4.1%) and ERBB2 (9/126, 7.1%) compared with ASC that had mutations in EGFR (660/1705, 38.7%), KRAS (143/625, 22.9%) and ERBB2 (6/196, 3.1%). The highest level of recurrent mutations was in pancreatic ASC where (108/126, 85.7%) reported mutations in KRAS. The EGFR mutations in ASC were similar in number and kind to those in lung adenocarcinoma. By standards of systematic review methodology and despite the large number of retrieved studies, we did not find adequate evidence for a distinctive molecular profile of either MEC or ASC that could definitively aid in its classification, especially in histologically difficult cases that are negative for MAML2 rearrangement. The case series included in this review indicate the relevance of MAML2 rearrangement to support the diagnosis of MEC, findings that should be confirmed by additional research with adequate study design.

Clinical Diagnostic Application of Contrast-Enhanced Ultrasound in Focal Lesions of the Salivary Glands

OBJECTIVES

To evaluate the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) for focal benign and malignant lesions of the salivary glands, as well as for common benign lesions.

METHODS

A total of 91 patients with focal lesions of the salivary glands were included in this study. In this study, CEUS was used to study the differential diagnosis of focal benign and malignant lesions of the salivary gland and the most common benign tumors, that is, pleomorphic adenoma (PA) and adenolymphoma.

RESULTS

The differences between focal benign and malignant lesions in the salivary glands were statistically significant (P < .05) in terms of qualitative CEUS indicators, enhancement pattern, enhancement homogeneity, enhancement margin, and enhanced lesion size, whereas the differences were not statistically significant (P > .05) in terms of wash-in and wash-out pattern, enhancement degree. Blurred margins and increased size of the lesion after enhancement are two CEUS features independently associated with focal malignant lesions of the salivary gland. The differences between salivary gland PA and adenolymphoma were statistically significant (P < .05) in terms of wash-in pattern, enhancement degree, enhancement homogeneity, and enhancement pattern, but not in terms of wash-out pattern, enhancement margin, and enhanced lesion size (P > .05).

CONCLUSIONS

As an economical, convenient, and safe imaging method, CEUS has important clinical value in distinguishing benign and malignant salivary glands.

Comprehensive Molecular Profiling of Oncocytic Salivary Gland Malignancies

Oncocytic histologic features can be seen in a variety of salivary gland carcinomas. We performed a comprehensive molecular profiling of 15 salivary gland malignancies with oncocytic features (diagnosed as oncocytic carcinoma, carcinoma NOS with oncocytic features, or salivary duct carcinoma with oncocytic features). We reveal multiple novel molecular alterations that have not been previously described in other salivary gland malignancies, including, but not limited to, KEL amplification (13.3%, 2/15), PARP1 amplification (13.3%, 2/15), and EPHB4 amplification (13.3%, 2/15). Alterations in KMT2C (13.3%, 2/15), ERBB3 (13.3%, 2/15), CTNNA1 (13.3%, 2/15), and SMAD4 (20%, 3/15) were also found in this series and have been reported in other salivary gland malignancies. Alterations that have been reported in salivary duct carcinoma were also identified, including TP53 (40%, 6/15) , ERBB2 mutations (13.3%, 2/15) , ERBB2 amplification (13.3%, 2/15), PIK3CA (26.7%, 4/15) , PTEN (20%, 3/15), BRCA2 (20%, 3/15), BRAF (20%, 3/15), CDKN2A/B (20%, 3/15), CDH1 (13.3%, 2/15), and HRAS (13.3%, 2/15). Oncocytic salivary gland malignancies are a molecularly heterogenous group of tumors with partial overlap with salivary duct carcinoma subtypes.

Frequency and imaging features of the adjacent osseous changes of salivary gland carcinomas in the head and neck region

PURPOSE

The association between salivary gland carcinomas and adjacent osseous changes in the head and neck region is not clear. We evaluated the frequency and imaging features of such changes and investigated the specific characteristics of salivary gland carcinomas associated with them.

METHODS

A total of 118 patients with histologically proven salivary gland carcinomas were retrospectively reviewed. The imaging characteristics of osseous changes were sorted into three categories based on computed tomography images: sclerotic change, erosive change, and lytic change. The frequency of all these osseous changes and any one of them was compared between different pathologies using Fisher's exact test. Odds ratios were calculated to evaluate the association between these changes and perineural spread.

RESULTS

Osseous changes were found in 21 (18%) of 118 cases. Among these, seven (6%) cases were with sclerotic, nine (8%) with erosive, and nine (8%) with lytic changes (four with mixed change). Adenoid cystic carcinoma showed a significantly higher frequency of sclerotic and erosive changes, and either osseous change, than the other salivary gland carcinomas (p < 0.001 for each). Sclerotic changes were only present in the adenoid cystic carcinomas. Perineural spread was a significant factor in showing higher osseous change frequencies (odds ratio = 3.98, p = 0.006).

CONCLUSION

Among salivary gland carcinomas in the head and neck region, adenoid cystic carcinomas had a significantly higher frequency of adjacent osseous changes, especially sclerotic changes, than other salivary gland carcinomas.

Full-Thickness Craniodural Metastasis with Leptomeningeal Infiltration of Salivary Origin: A Radiological Lesson and a Technical Remark

Calvarial metastases are a relatively rare entity, with an overall incidence of 3-4%. Among these cases, metastases arising from salivary gland cancers are even rarer; in fact, large studies regarding salivary gland tumors showed that brain metastases are observed in 0.8% of the cases. Generally, bone metastases have been described in proximity to primary tumors, while bloodstream-disseminated lesions are often located inside the brain parenchyma. During every surgical step, traction on lower-lying infiltrated tissues must be avoided in order to successfully remove the lesion. This case report presents the first ever case of a 67-year-old woman affected by submandibular gland undifferentiated adenocarcinoma metastasis with a full-thickness involvement of the calvarium, pachy- and leptomeninges.

Clinico-Epidemiological Analysis of Most Prevalent Parotid Gland Carcinomas in Poland over a 20-Year Period

(1) Background: Malignant tumours of the salivary glands have different clinical and histopathological characteristics. They most commonly involve the parotid gland. Histopathologically, the most common are mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC), acinic cell carcinoma (AcCC), adenocarcinoma, carcinoma in pleomorphic adenoma (CPA), and squamous cell carcinoma (SCC). (2) Methods: We analysed 2318 patients with malignant parotid gland tumours reported to the National Cancer Registry (NCR) in Poland over 20 years (1999-2018). The demographic characteristics of patients, clinical factors, and overall survival (OS) were analysed. (3) Results: The average age was 61.33 ± 16.1 years. The majority were males (55%) and urban citizens (64%). High percentage of carcinomas was diagnosed in locoregional (33.7%) and systemic (10.4%) stadium. The most prevalent diagnoses were SCC (33.3%) and adenocarcinoma (19.6%). Surgical resection with adjuvant RT (42.1%) was the most common treatment. The OS analysis showed a median survival time of 5.6 years. The most favorable median OS was found in patients with AcCC (18.30 years), the worst for SCC (1.58 years). (4) Conclusion: AcCC has the best prognosis and SCC the worst. Tumour stadium, treatment, and demographic factors affect prognosis. Improvements in diagnosis and re-evaluation of treatment standards are necessary to enhance the outcome of patients with parotid gland cancers in Poland.

Nondiagnostic category of Milan System for Reporting Pediatric Salivary Gland Cytopathology: outcomes and root cause analysis

BACKGROUND

Fine-needle aspiration (FNA) results classified as the nondiagnostic category of the Milan system for reporting salivary gland cytopathology (MSRSGC) may be infrequently encountered in children. Clinical management may be challenging due to lack of data regarding outcomes and underlying causes.

METHODS

We retrospectively analyzed 106 consecutive pediatric salivary gland FNAs (2000-2020; 45% performed under image guidance). The outcomes of patients with nondiagnostic results were analyzed. Clinical parameters, FNA procedural parameters, and histopathologic parameters were compared between diagnostic and nondiagnostic cases. A root cause analysis was performed using the fishbone diagram and the 5 Whys method.

RESULTS

A total of 103 initial FNAs were identified. The nondiagnostic rates for initial and repeat biopsy were 16% (16/103) and 67% (2/3), respectively. Initial nondiagnostic FNAs were most frequently managed by clinical/radiologic follow-up only (56%, 9/16), followed by direct surgery (19%, 3/16) and repeat FNA (19%, 3/16). By histologic and clinical/radiologic follow-up, the risk of malignancy for nondiagnostic cases was zero. Palpation guidance (P < .05), inadequate sampling determined by rapid on-site evaluation (P < .01), and lesions with cystic, vascular, or diffuse nature (P < .05) were significantly associated with nondiagnostic results. By root cause analysis, proceduralist sampling error and lack of ultrasound guidance were the most common primary and secondary causes, respectively.

CONCLUSIONS

Pediatric salivary gland lesions of the nondiagnostic MSRSGC category have minimal risk of malignancy and may be successfully managed by clinical/radiologic follow-up. The root causes for nondiagnostic results were often multifactorial and primarily related to proceduralist sampling, characteristics of the lesions, and lack of ultrasound guidance.

Multiplexed single-cell analysis of FNA allows accurate diagnosis of salivary gland tumors

Diagnosing salivary gland tumors (SGTs) through fine-needle aspiration (FNA) biopsies is challenging due to the overlapping cytomorphologic features between benign and malignant tumors. The authors developed an innovative, multiplexed cycling technology for the rapid analyses of single cells obtained from FNA that can facilitate the molecular analyses and diagnosis of SGTs. Antibodies against 29 protein markers associated with 7 SGT subtypes were validated and chemically modified via custom linker-bio-orthogonal probes (FAST). Single-cell homogenates and FNA samples were profiled by FAST cyclic imaging and computational analysis. A prediction model was generated using a training set of 151,926 cells from primary SGTs (N = 26) and validated on a separate cohort (N = 30). Companion biomarker testing, such as neurotrophic tyrosine receptor kinase (NTRK), was also assessed with the FAST technology. The FAST molecular diagnostic assay was able to distinguish between benign and malignant SGTs with an accuracy of 0.86 for single-cell homogenate samples and 0.88 for FNA samples. Profiling of multiple markers as compared to a single marker increased the diagnostic accuracy (0.82 as compared to 0.65-0.74, respectively), independent of the cell number sampled. NTRK expression was also assessed by the FAST assay, highlighting the potential therapeutic application of this technology. Application of the novel multiplexed single-cell technology facilitates rapid biomarker testing from FNA samples at low cost. The customizable and modular FAST-FNA approach has relevance to multiple pathologies and organ systems where cytologic samples are often scarce and/or indeterminate resulting in improved diagnostic workflows and timely therapeutic clinical decision-making.

Case Report: Papillary Lesions at the Mouth Floor May Mimic Sialadenoma Papilliferum

Salivary gland tumor Sialadenoma papilliferum (SialP) clinically resembles papillary epithelial lesions, such as squamous papilloma (SqP) or verrucous leukoplakia. Pathological sampling including an adequate depth of both the mucosa and submucosa layer is required for discrimination between the diseases. Though ductal proliferation in the submucosa is characteristic in SialP, papillary lesions arising at the mouth floor, specifically near the ductal orifice, are more problematic. Salivary gland ductal ectasia, along with the overlying papillary hyperplasia, may mimic the biphasic tumorous growth pattern of SialP, making discrimination extremely difficult. Further cellular dysplasia in the papillary mucosal lesion raises the possibility of malignant transformation in a known benign lesion, SialP. Herein, we present a case of SqP at the mouth floor which mimicked both clinical and pathological features of SialP and compared it with a definite case of SialP. Moreover, we discuss major differential points that clinicians and pathologists should consider during diagnosis of oral papillary lesions arising near the salivary glands.

A symptomatic intercalated duct lesion of the parotid gland: a case report with immunohistochemical and genetic analyses

Intercalated duct lesions (IDLs) are usually asymptomatic. We report a case of IDL, in which a palpable mass formed. The patient was a 45-year-old Japanese male, who noticed a mass in the left parotid region. The nodular lesion was well-circumscribed, but did not have a fibrous capsule or exhibit infiltrative growth. It contained a small cystic space and consisted of basaloid cells arranged in a cribriform pattern and inner ductal cells. It had some solid areas of nest-like proliferation displaying mild cellular atypia. Immunohistochemically, the luminal cells were positive for cytokeratin (CK)7 and epithelial membrane antigen, and the abluminal cells were positive for CK5/6, p63, and DOG1. S-100 protein-positive stromal cells were also seen. The lesion's cells were all positive for SOX10, and the nuclei of some basaloid cells were positive for β-catenin. The Ki-67 labeling index was 3.8%. The ductal cells contained diastase-digestion-resistant, Periodic acid Schiff-positive zymogen granules. Genetically, the lesion harbored a missense mutation in the CTNNB1 gene. We diagnosed the lesion as an IDL. As IDLs are usually small non-neoplastic lesions, symptomatic cases are rare. Based on its common immunohistochemical and genetic features, IDL may be a precursor of basal cell adenoma/adenocarcinoma, such as intercalated duct adenoma.

MSRSGC: A prospective study of heterogenous group atypia of undetermined significance

CONTEXT

: Many standard books, literatures, and internet described the characteristic lineament of each salivary gland lesion. Nevertheless, there are dozens of disarray, confusion, and unmanageable morphological features regarding proper reporting. To fight with these issues, Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) was introduced in 2018, but still the third category, Atypia of undetermined significance (AUS), poses difficulties for the pathologists and clinicians for a definite interpretation.

AIM

: The aim is to analyze the risk of neoplasia (RON) and risk of malignancy (ROM) of Milan's category III (AUS) by subdividing into six groups based on cytolomorphology.

SETTINGS AND DESIGN

:The duration of study was from March 2018 to may 2021 with the focus on ROM and RON of all Milan's categories with especial attention on AUS.

METHODS AND MATERIAL

: Result of total 329 Fine Needle Aspiration Cytology of salivary glands was categorized according to MSRSGC. On the basis of cytomorphology, further subtyping of AUS and its cytohistopathology correlation was done. The ROM and RON of each subtype was analyzed.

STATISTICAL ANALYSIS

All data were calculated by existing formulas.

RESULTS

Out of 329 aspirates, 24 (07.29%) cases belong to AUS with availability of histology in 13 (54.17%) cases. RON and ROM was 84.62% and 53.85%, respectively. Cases of lymphocytes with nuclear atypia (L-NA) was the most prevalent (29.17%). The RON were 60.00%, 68.57,% 84.62%, 94.87%, 87.50%, 100%, 100% and the ROM were 20.00%, 11.42%, 53.85%, 05.13%, 43.75%, 83.33% and 100% in each Milan's categories I, II, III, IVa, IVb, V, and VI, respectively. ROM was the highest in cystic fluid with nuclear atypia (C-NA) (100.0%), followed by basaloid cells (75%), L-NA (66.675), and SC (50%), but ROM was zero in NA and oncocytic cells.

CONCLUSIONS

Subgrouping of AUS helps to dissipate the muddiness and provide more exact and reproducible diagnostic and prognostic tool.

Clear Cell Neoplasms of Salivary Glands: A Diagnostic Challenge

This review focuses on the heterogenous group of clear cell neoplasms of salivary glands and attempts to identify major differential diagnostic features. Within the head and neck region, clear cells are found most commonly in salivary gland tumors, but may also be seen in tumors of squamous or odontogenic epithelial origin, primary or metastatic carcinomas, benign or malignant melanocytic lesions, or benign or malignant mesenchymal tumors. Clear cells occur fairly commonly among a wide variety of salivary gland neoplasms, but mostly they constitute only a minor component of the tumor cell population. Clear cells represent a major diagnostic feature in two salivary gland neoplasms, epithelial-myoepithelial carcinoma and hyalinizing clear cell carcinoma. In addition, salivary gland neoplasms composed predominantly of clear cells could also include clear cell variants of other salivary neoplasms, such as mucoepidermoid carcinoma and myoepithelial carcinoma, but their tumor type-specific histologic features may only be available in limited nonclear cell areas of the tumor. Diagnosing predominantly clear cell salivary gland tumors is difficult because the immunoprofiles and morphologic features may overlap and the same tumor entity may also have a wide range of other histologic presentations. Many salivary gland tumors are characterized by tumor type-specific genomic alterations, particularly gene fusions of the ETV6 gene in secretory carcinoma, the MYB and MYBL1 genes in adenoid cystic carcinoma, the MAML2 gene in mucoepidermoid carcinoma, the EWSR1 gene in hyalinizing clear cell carcinoma, and others. Thus, along with conventional histopathologic examination and immunoprofiling, molecular and genetic tests may be important in the diagnosis of salivary gland clear cell tumors by demonstrating genetic alterations specific to them.

MYB RNA In Situ Hybridization Is a Useful Diagnostic Tool to Distinguish Breast Adenoid Cystic Carcinoma From Other Triple-negative Breast Carcinomas

Breast adenoid cystic carcinoma (AdCC) has overlapping features with basal-like triple-negative breast carcinoma (TNBC), yet carries a more favorable prognosis, and accurate diagnosis is critical. Like salivary gland AdCC, breast AdCC demonstrates recurrent alterations in the MYB gene. Novel chromogenic RNA in situ hybridization (ISH) for MYB has emerged as sensitive and specific for salivary gland AdCC. Here, we evaluate MYB RNA ISH in invasive ductal carcinomas (IDCs) including basal-like TNBC, and in the histologic mimics ductal carcinoma in situ (DCIS) and collagenous spherulosis. MYB RNA ISH was also performed on previously constructed tissue microarrays containing 78 evaluable IDC, including 30 basal-like TNBC (EGFR+ and/or CK5/6+), 19 luminal A (ER+/HER-2-), 12 HER-2+ (ER-/HER-2+), 11 non-basal-like TNBC, and 6 luminal B (ER+/HER-2+). MYB RNA ISH overexpression was seen in 100% (n=18/18) of primary breast AdCC and 10% (n=8/78) of IDC (P<0.0001). MYB RNA ISH was overexpressed in 37% (n=7/19) of luminal A and 8% (n=1/12) of HER-2+ IDC, and in no cases of TNBC or luminal B IDC. The majority (67%, n=8/12) of DCIS and all (n=7) cases of collagenous spherulosis demonstrated overexpression of MYB RNA. MYB gene rearrangement was detected in 67% (n=4/6) evaluable AdCC. Although MYB RNA ISH overexpression cannot be used to distinguish between cribriform DCIS or collagenous spherulosis and AdCC, MYB RNA ISH is absent in basal-like TNBC and rare in ER+ or HER-2+ IDC. MYB RNA ISH could be a useful, sensitive, and rapid diagnostic adjunct in the workup of a triple-negative carcinoma in the breast.

Primary Mucoepidermoid Carcinoma of the Lacrimal Apparatus

PURPOSE

In this study, we evaluated the clinicopathologic and molecular characteristics of lacrimal apparatus mucoepidermoid carcinoma (MEC) to define its typical diagnostic features.

DESIGN

Retrospective observational case series.

METHODS

Institutional pathology records between 2011 and 2021 were searched for all cases of lacrimal apparatus MEC.

RESULTS

A total of 2 male and 6 female patients ranging in age from 18 to 83 years (median 56, mean 54) were included. Six lacrimal apparatus MECs were found in the lacrimal gland, and 2 cases occurred in the lacrimal sac and nasolacrimal duct. Histologically, there were 6 cases of conventional MEC, 1 clear-cell variant of MEC, and 1 oncocytic variant of MEC for a total of 8 cases. There were 3 low-grade cases and 5 high-grade cases. All 8 cases were evaluated via immunohistochemistry, and the results were positive (scores 1-4) for pankeratin, 34betaE12, p63, p40, CK7, CK8, and CK19, with a relatively higher expression of p63 observed in high-grade MEC. The presence of human papillomavirus (HPV) type 6 DNA was found in 4 patients. MAML2 fluorescence in situ hybridization was positive for MAML2 rearrangement in 3 lacrimal gland tumors (2 low-grade and 1 high-grade). Six tumors were managed with radical resection, and 2 patients underwent orbital exenteration. Postoperative radiation therapy was delivered to 6 patients, and chemotherapy was administered to 1 patient.

CONCLUSIONS

MECs of the lacrimal apparatus are rare tumors, and the rate of MAML2 translocations is lower than that in salivary MECs. Lacrimal gland and lacrimal sac MECs may not be of the same subtypes intrinsically because of the difference in MAML2 translocation, anatomy, and clinical course. The etiologic function of HPV type 6 infection should be explored in lacrimal apparatus MECs. Radical surgery is the treatment of choice. The description of these unique findings may assist in the definitive diagnosis of and improve our understanding of lacrimal apparatus MEC.

Sinonasal mixed transitional epithelial-seromucinous papillary glandular neoplasms with BRAF p.V600E mutations - sinonasal analogues to the sialadenoma papilliferum family tumors

Sinonasal non-intestinal type adenocarcinoma (non-ITAC) is a heterogeneous category that may benefit from improved taxonomy. With the recognition that most non-ITAC are phenotypically seromucinous, stratification may be improved by applying salivary type morphologic criteria and molecular findings. We report two cases of papillary seromucinous adenocarcinoma with sinonasal papilloma-like surface components that show histologic and molecular features analogous to the salivary sialadenoma papilliferum family of tumors. Case 1 concerns a 50-year-old female who presented with a left anterior nasoethmoid polyp, while case 2 is that of a 74 year old female with nasal polyposis. Histologically, both cases demonstrated a surface transitional sinonasal papilloma-like component (more prominent in case 2) with a deeper bilayered glandular component showing papillary and tufted micropapillary growth of monomorphic columnar to cuboidal cells with eosinophilic cytoplasm. Case 1 also showed a deep cribriform/microcystic component. Immunostains showed a delimiting p63/p40 positive basal layer around the SOX-10 positive glandular elements, while the transitional sinonasal papilloma-like components were diffusely p63/p40 positive. Like sialadenoma papilliferum and related tumors, both cases demonstrated BRAF p.V600E mutations in both components and no other alterations. The patients remain disease free at 9 and 19 months respectively. Our cases illustrate a novel sinonasal lesion and suggest that improved morphologic and molecular categorization may refine and reduce the category of non-ITAC.

Mutually Exclusive Expression of COL11A1 by CAFs and Tumour Cells in a Large panCancer and a Salivary Gland Carcinoma Cohort

Procollagen 11A1 (COL11A1) is a central component of the extracellular matrix in many carcinomas, which is considered to be mainly produced by cancer associated fibroblasts (CAFs). As COL11A1 expression correlates with adverse prognosis and is implicated in chemoresistance, it is a promising putative target. For the first time, we used RNA in-situ hybridization to systematically identify the cells that produce COL11A1 in the ten most prevalent carcinoma types, lymphomas (n = 275) and corresponding normal tissue (n = 55; panCancer cohort). Moreover, as most salivary gland carcinomas (SGC) display distinct stromal architectures, we also analysed 110 SGC. The corresponding protein formation of COL11A1 was determined by MALDI-TOF-MS-Imaging. We report that colon, breast and salivary duct carcinomas are highly infiltrated by COL11A1 positive CAFs (CAFs_COL11A1) and might thus be promising candidates for antidesmoplastic or COL11A1-targeted therapies. The amount of CAFs_COL11A1 correlated significantly with tumour grade, tumour stage and nodal spread in the panCancer cohort. Significant associations between CAFs_COL11A1 and vascular invasion, perineural spread and nodal spread were observed in the SGC cohort. Also, we discovered that tumour cells of intercalated duct derived SGC and CAFs produce COL11A1 in a mutually exclusive manner. Our findings represent a novel mode of extracellular matrix production in carcinomas and could be highly relevant in the future. Our findings elucidate the mode of COL11A1 expression in very different carcinoma types and may aid to categorise tumours in the setting of possible future COL11A1-related therapies.

[Clinical analysis of 61 cases of salivary duct carcinoma]

The clinical data of 61 patients of salivary duct carcinoma admitted to the First Medical Centre of Chinese PLA General Hospital from January 2010 to December 2020 were retrospectively reviewed. A total of 55 patients (90.2%) were male and 6 (9.8%) were female. There were 51 patients (83.6%) aged≥50 years. The primary tumor of 45 patients (73.8%) were from the parotid gland. There were 35 patients (57.4%) who had cervical lymph node metastasis and 25 patients (41.0%) had distant metastasis. All patients underwent surgery and 50 of them (82.0%) received adjuvant radiotherapy. The 3-year and 5-year survival rates were 58.0% and 43.3%, respectively. Compared with the patients who had undergone surgery only, the survival rates of those who had postoperative adjuvant radiotherapy and chemoradiotherapy were higher. It can be seen that radical surgical treatment is necessary, and postoperative radiotherapy can reduce the recurrence rate and increase the survival rate to a certain extent.

Primary salivary gland-type polymorphous adenocarcinoma in the lung: A case report and literature review

RATIONALE

Polymorphous low-grade adenocarcinoma is a low-risk infiltrative malignant tumor of the salivary glands. However, some of these tumors are more malignant than the low-grade tumors and therefore, according to the most recent recommendation of the World Health Organization, they are renamed as polymorphous adenocarcinomas (PACs). Primary polymorphous low-grade adenocarcinomas/PACs of the lungs are rare. Herein, we report a case of primary PAC of the lung with bronchial cartilage and perineural invasion, and lymph node metastasis.

PATIENT CONCERNS

A 58-year-old man had developed fever half a month prior, without chills or other accompanying symptoms, and the underlying reasons were unknown. His self-measured temperature was up to 39°C, accompanied by cough and expectoration, yellow and thin sputum, and shortness of breath. The patient's general state was normal, and respiratory sounds originating from the right lung were weak. Enhancement computed tomography revealed that the bronchial lumen of the basal segment of the lower lobe of the right lung was narrow; soft tissue density nodules were seen, with a range of approximately 2.4 cm × 1.3 cm.

DIAGNOSIS

Based on clinical information, morphological features, and immunohistochemistry results, the pathological diagnosis was primary PAC of the lungs.

INTERVENTION

Thoracoscopic resection of the middle and lower lobes of the right lung was performed, further extended dissection of the mediastinal lymph nodes was performed.

OUTCOMES

The postoperative course was uneventful.

LESSONS

Primary PAC of the lung is rare and may cause misdiagnosis. When encountering a lung tumor with diverse tissue structures, uniform cell type and nerve invasion, we should consider the possibility of PAC. Morphological and immunohistochemical features can be useful for diagnosing primary PAC of the lungs.

Secretory Carcinoma of the Salivary Gland: A Rarity in Children

Originally described as mammary analog secretory carcinoma (SC), SC of the salivary gland is a rare malignancy with morphologic and molecular similarities to SC of the breast. We present 2 children with salivary gland SC with the classic ETV6-NTRK3 gene fusion, including 1 with lymph node metastases. Both patients underwent surgical resection and were in remission 24 months postsurgery. One patient was additionally found to have synchronous papillary thyroid carcinoma with a TFG-MET fusion. A review of published cases highlights the expanding molecular profile and confirms the favorable course of salivary gland SC after surgical resection.

Salivary gland neoplasms with basaloid features in the era of the Milan system for reporting salivary gland cytology: Classification and interobserver agreement

BACKGROUND

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been shown to have moderate to good reproducibility for categorization of salivary gland fine-needle aspiration (FNA) specimens. Less is known of its accuracy and interobserver reproducibility for categorization of the diagnostically difficult group of basaloid neoplasms.

METHODS

Forty-five salivary gland specimens with a basaloid morphology (pleomorphic and monomorphic adenomas and adenoid cystic carcinomas) were independently assigned by seven cytopathologists to one of the MSRSGC categories. Interobserver agreement was assessed for average agreement, chance expected agreement and by Cohen's κ and diagnostic accuracy. Correlation of the salivary gland neoplasm of unknown malignant potential (SUMP) category with histologic diagnosis and benign or malignant designation along with interobserver reproducibility were calculated.

RESULTS

Average observed agreement for assignment to the MSRSGC was 46% and Cohen's κ = 0.2%. The SUMP category did not correlate with tumor type or with the benign or malignant nature of the neoplasm. Diagnostic specificity and sensitivity were 92% and 100% for consensus diagnosis, but were 76% and 77% for individual diagnoses.

CONCLUSION

The interobserver agreement in categorizing basaloid neoplasms by the MSRSGC is poorer than for salivary gland lesions overall. This reflects the difficulty in diagnosing basaloid neoplasms. Nonetheless, diagnostic accuracy appears similar to that of salivary gland neoplasms as a whole.

Diagnostic Value of MAML2 Rearrangements in Mucoepidermoid Carcinoma

Mucoepidermoid carcinoma (MEC) is often seen in salivary glands and can harbor MAML2 translocations (MAML2+). The translocation status has diagnostic utility as an objective confirmation of the MEC diagnosis, for example, when distinction from the more aggressive adenosquamous carcinoma (ASC) is not straightforward. To assess the diagnostic relevance of MAML2, we examined our 5-year experience in prospective testing of 8106 solid tumors using RNA-seq panel testing in combinations with a two-round Delphi-based scenario survey. The prevalence of MAML2+ across all tumors was 0.28% (n = 23/8106) and the majority of MAML2+ cases were found in head and neck tumors (78.3%), where the overall prevalence was 5.9% (n = 18/307). The sensitivity of MAML2 for MEC was 60% and most cases (80%) were submitted for diagnostic confirmation; in 24% of cases, the MAML2 results changed the working diagnosis. An independent survey of 15 experts showed relative importance indexes of 0.8 and 0.65 for "confirmatory MAML2 testing" in suspected MEC and ASC, respectively. Real-world evidence confirmed that the added value of MAML2 is a composite of an imperfect confirmation test for MEC and a highly specific exclusion tool for the diagnosis of ASC. Real-world evidence can help move a rare molecular-genetic biomarker from an emerging tool to the clinic.

Application of Contrast-Enhanced Ultrasound Combined with Elastic Imaging Technology in Differential Diagnosis of Salivary Gland Tumors

This paper proposes the effect of contrast-enhanced ultrasound combined with real-time elastic imaging technology in the differential diagnosis of salivary gland tumors. 200 patients were selected, including 120 males and 60 females. The age ranged from 9 to 83 years, with an average of 55.4 years. Among the 200 cases, there were 90 cases of single parotid gland on the right, 77 cases of single parotid gland on the left, 2 cases of bilateral (single parotid gland on each side), 2 cases of multiple parotid gland on the right (2 lesions), 1 case of 2 lesions on the left and 1 lesion on the right, and 1 case of multiple parotid gland on the left (4 lesions). 135 cases were located in the superficial lobe (78%) and 38 cases (22%) in the deep lobe of parotid gland. The ARIETTA 70 color Doppler ultrasound diagnostic instrument is used. The equipment is equipped with high-frequency contrast probe, real-time elastic imaging technology, and related software. The results showed that the detection rate of salivary gland tumors by ultrasound was 100% and the diagnostic coincidence rate was 71% (123/173). Ultrasound can not only identify the tumors in and around the parotid gland but also identify the location, size, and internal structure of the tumors. Combined with CDFI, it can make qualitative diagnosis of most benign and malignant salivary gland tumors and provide help for clinical treatment and operation plan. It is proved that contrast-enhanced ultrasound and real-time elastic imaging technology have advantages over gray-scale ultrasound in differentiating benign and malignant superficial enlarged lymph nodes, and the combined use can effectively improve the diagnostic efficiency.

Intraosseous mucoepidermoid carcinoma of mandible: a rare case presentation and literature review

Intraosseous mucoepidermoid carcinoma (IMC) is an atypical salivary gland neoplasm commonly seen in middle-aged adults. Their presentation in young individuals below the age group of 20 years is sporadic. Treatment modality mainly includes radical surgical resection for malignant tumours. There were only 13 reported cases of IMC of mandible below the age of 20 years in the English literature. All the reported cases were only managed with wide resection and radiotherapy. Surgical resection leads to loss of form and function in the young population, decreasing their morale. Hence, reconstruction should be mandated in young individuals for restoring function and aesthetics. We present a case of IMC of the mandible in a young female individual resected and reconstructed with a free fibula bone graft. Satisfactory healing is elicited with no recurrence at the 2-year follow-up period.

Zymogen-poor acinic cell carcinoma of the soft palate with high-grade transformation

Acinic cell carcinoma is an uncommon malignant salivary gland tumour accounting for approximately 6-7% of all salivary gland neoplasms. The key diagnostic feature of acinic cell carcinoma is the presence of acinar cell differentiation characterised by cytoplasmic zymogen secretory granules. This tumour shows a variety of growth patterns, including solid, microcystic, follicular and papillary cystic patterns. Acinic cell carcinoma is typically a cytologically low-grade malignancy. Acinic cell carcinomas with high-grade transformation (HGT) are exceedingly rare and are reported to have a more aggressive clinical course than conventional acinic cell carcinoma. This is a case report of this uncommon entity with high-grade transformation arising on the soft palate in a 64-year-old woman.

Pleomorphic Adenoma of Minor Salivary Gland

Pleomorphic adenoma is a benign tumor of salivary glands, arising from minor salivary glands, is very rare and presents with a minor female predilection; and the highest occurrence is between the fourth and sixth decades of life. It is of glandular origin, usually presenting as a slowly growing, painless, firm swelling that does not cause ulceration of the overlying mucosa. In this case, a 27-year male presented with swelling on buccal mucosa for three years. The swelling was firm and well circumscribed. Excisional biopsy was done under general anesthesia and the mass was excised. The histopathological evaluation revealed pleomorphic adenoma. This case highlights the need to keep this entity in the differential diagnosis of intra-oral indolent swellings of some duration. Key Words: Pleomorphic adenoma, Buccal mucosa, Minor salivary glands.

Occult nodal metastasis in major salivary gland malignancy: An update from the National Cancer Database

OBJECTIVES

Malignant salivary gland tumors are rare neoplasms that are vastly heterogenous in their histological patterns and clinical behaviors. As a consequence, studies have lacked the robust sample sizes needed to define treatment strategies. In this study, we used the National Cancer Database to identify the incidence of occult nodal metastasis and effect on overall survival for the most common malignant salivary gland subtypes. A retrospective review of patients in the National Cancer Database with primary site malignancies of major salivary glands between 2004 and 2016 was performed. Subjects included in the study underwent surgical treatment with and without adjuvant radiation and had complete information on TNM pathological stage.

MATERIALS AND METHODS

8,689 patients with primary malignant salivary gland cancer were analyzed. The sample was stratified by histologic subtype. Univariate analysis of lymph node metastasis of the whole cohort showed a higher risk of death (p < 0.001), when compared to those without. Also when comparing occult vs evident metastasis, the risk of death was higher for the latter (p < 0.001).

RESULTS AND CONCLUSION

Occult cervical lymph node metastasis ranged from 14.9% to 35.8% in malignant salivary gland cancers, depending on histological subtype. Occult nodal metastasis was a poor prognostic factor with significantly worse overall survival.

The evolving role of molecular pathology in the diagnosis of salivary gland tumours with potential pitfalls

Salivary gland tumors are diagnostically challenging owing to the morphological diversity within any tumor type and overlapping histomorphology and immunohistochemistry amongst different tumours. In past two decades, rapid progress has been made in the field of understanding the pathogenesis of these tumours with the discovery of many tumour specific translocations and rearrangements. This includes CRTC1-MAML2 and CRTC-MAML2 in mucoepidermoid carcinoma, MYBNFIB and MYBL1-NFIB fusions in adenoid cystic carcinoma, PLAG1 and HMGA2 in pleomorphic adenoma, ETV6-NTRK3 in secretory carcinoma, NR4A3 rearrangements in acinic cell carcinoma, PRKD1 mutations in polymorphous adenocarcinoma and EWSR1-ATF1 in clear cell carcinoma. This review is a lens for progress made till date in the molecular pathology of salivary gland tumours with a special focus on their role as diagnostic tools and implications on clinical management of the patient as prognostic and predictive markers.

Proceedings of the North American Society of Head and Neck Pathology, Los Angeles, CA, March 20, 2022: Emerging Entities in Salivary Gland Tumor Pathology

Salivary gland tumor pathology is one of the most challenging areas in all head and neck surgical pathology. Compounding its inherent difficulty are numerous novel entities, variants and concepts, most of which have been based on recent molecular discoveries. This review will serve to update the practicing pathologist on a selected group of emerging entities in salivary gland tumor pathology.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Salivary Glands

The salivary gland section in the 5th edition of the World Health Organization Classification of Head and Neck Tumours features a description and inclusion of several new entities, including sclerosing polycystic adenoma, keratocystoma, intercalated duct adenoma, and striated duct adenoma among the benign neoplasms; and microsecretory adenocarcinoma and sclerosing microcystic adenocarcinoma as the new malignant entities. The new entry also includes mucinous adenocarcinoma subdivided into papillary, colloid, signet ring, and mixed subtypes with recurrent AKT1 E17K mutations across patterns suggesting that mucin-producing salivary adenocarcinomas represent a histologically diverse single entity that may be related to salivary intraductal papillary mucinous neoplasm (IPMN). Importantly, the number of entities in the salivary chapter has been reduced by omitting tumors or lesions if they do not occur exclusively or predominantly in salivary glands, including hemangioma, lipoma, nodular fasciitis and hematolymphoid tumors. They are now discussed in detail elsewhere in the book. Cribriform adenocarcinoma of salivary gland origin (CASG) now represents a distinctive subtype of polymorphous adenocarcinoma (PAC). PAC is defined as a clinically, histologically and molecularly heterogeneous disease group. Whether CASG is a different diagnostic category or a variant of PAC is still controversial. Poorly differentiated carcinomas and oncocytic carcinomas are discussed in the category "Salivary carcinoma not otherwise specified (NOS) and emerging entities". New defining genomic alterations have been characterized in many salivary gland tumors. In particular, they include gene fusions, which have shown to be tightly tumor-type specific, and thus valuable for use in diagnostically challenging cases. The recurrent molecular alterations were included in the definition of mucoepidermoid carcinoma, adenoid cystic carcinoma, secretory carcinoma, polymorphous adenocarcinoma, hyalinizing clear cell carcinoma, mucinous adenocarcinoma, and microsecretory adenocarcinoma.

Artemisinin potentiates apoptosis and triggers cell cycle arrest to attenuate malignant growth of salivary gland tumor cells

One of the rare malignant tumors developing within the glands of the buccal cavity in human beings is salivary gland tumors (SGTs). The hallmark of SGTs is the fusion of nuclear factor IB (NFIB) and myeloblastosis (MYB) genes developed after the translocation of q22-23; p23-24. Although the aetiology of SGTs is not clear, however, the therapeutic modalities are surgical resection followed by the combination of chemotherapy and radiotherapy if a chance of recurrence seems to develop. Owing to have numerous side effects of chemotherapy, the drug development has been shifted to natural products with minimal side effects. One of the key phytochemical artemisinin derived from wormwood Artemisia annua exhibits various pharmacological activities against various in-vivo and in-vitro cellular models. Here, we evaluated the cytotoxic potential of artemisinin against A-253 cells with possible underlying cell death mechanisms. Our results showed that artemisinin reduces the proliferation of cells in a concentration-dependent manner and displays IC50 value in a range of 10.23, 14.21 μM, and 203.18 μM against A-253/HTB-41 and transformed salivary gland SMIE cells, respectively. Flow cytometry analysis demonstrated that artemisinin promotes a significant amount of apoptotic cellular population and triggers G0/G1 arrest of A-253 cells in a concentration-dependent manner. To verify the mechanism of cell death induced by artemisinin in A-253 cells, we found an increased level of Bax, Bim, Bad, Bak and reduced level of antiapoptotic protein Bcl-2, Bcl-XL with concomitant release of mitochondrial resident protein cytochrome c into the cytoplasm. Additionally, we found that artemisinin augments the production of reactive oxygen species which further leads to the activation of proapoptotic proteins PARP1, and caspase-3, in a concentration-dependent manner thereby triggering apoptosis. In conclusion, artemisinin exhibits promising anticancer therapeutic potential against A-253 cells and needs further validation of in-vitro results in preclinical models.

Management of malignant submandibular gland tumors: A 30-year experience from a single center

OBJECTIVE

Owing to histologic heterogeneity, biological behavior, and rarity, recommendations for the treatment of malignant submandibular gland tumors (MSGT) are inconsistent. The aim of this study was to present a single-center experience in the treatment of MSGT with an emphasis on surgical treatment, including indication on elective neck dissection (END).

STUDY DESIGN

Twenty-four MSGT were primary surgically treated (gland excision with neck dissection). Their records were retrospectively collected and analyzed.

RESULTS

The most frequent histology was adenoid cystic carcinoma (41.6%), followed by mucoepidermoid carcinoma (25%) and carcinoma ex pleomorphic adenoma (16.7%). There were 18 elective and 6 therapeutic neck dissections. Histopathologic examination confirmed 29% (7/24) of positive neck dissection specimens. The Kaplan-Meier analysis presented rates of disease-specific survival, disease-free survival, and overall survival (OS) of 81%, 78%, and 52% at 5 years, respectively. Patients undergoing postoperative radiotherapy had significantly higher OS rates compared with patients treated with surgery alone (P = .0209).

CONCLUSION

Results of this study suggest that END has questionable benefit in early stage MSGT. Elective selective neck dissection levels I-III is recommended in high-grade and advanced stage MSGT without evidence of multilevel lymphadenopathy.

Warthin-Like Mucoepidermoid Carcinoma: A Morphological Spectrum - A Report of 3 Cases with Histological and Cytological Findings and Review of the Literature

BACKGROUND

Mucoepidermoid carcinoma (MEC) showing Warthin's tumor (WT)-like features is a low-grade malignancy which should be differentiated from WT. Morphological features may be distinctly different in each case, causing diagnostic difficulties.

CASE PRESENTATION

Three cases were presented and discussed with their morphologies. All cases that presented with a mass in the parotid gland went to parotidectomy, and all had preoperative fine-needle aspirations (FNAs). Case 1 was a 16-year-old female; FNA was suggestive of WT and initially interpreted as WT histologically. Case 2 was a 27-year-old male; FNA was interpreted as noninformative due to the presence of cyst fluid only. Case 3 was a 53-year-old male and cytologically was found to be suspicious for MEC which contained squamous and goblet cells on a mucoid background. On histopathological examination, case 2 and case 3 were morphologically consistent with low-grade MEC with WT-like features. Prominent lymphoid stroma and the cystic pattern were the characters of these tumors. Case 1 had the classical WT appearance with some mucinous and squamous metaplasia which could only be interpreted as MEC after the detection of MAML2 rearrangement by FISH. The other 2 showed either focal or relatively diffuse usual low-grade MEC findings, and case 3 was also confirmed by MAML2 rearrangement.

CONCLUSION

Cytological and histopathological features revealed a spectrum. Differentiating WT-like MECs from ordinary WTs may be challenging. On the one end of the spectrum, they may look very much like WT, and on the other end, even though usual MEC features are present, still, WT-like appearance may pose diagnostic difficulty. Showing MAML2 rearrangement in these cases is very helpful. The presence of mucinous and squamous cells in an otherwise WT-like looking tumor should be alarming for MEC, and if possible, each case should be analyzed for MAML2 rearrangement.