A review: Immunological markers for malignant salivary gland tumors

Establishment and characterization of cMYB-expressing human salivary adenoid cystic carcinoma cell lines (UM-HACC-14, UM-HACC-6) and matching patient-derived xenograft model (UM-PDX-HACC-14)

OBJECTIVE

Limited availability of authentic human adenoid cystic carcinoma (ACC) cell lines has hindered progress in understanding mechanisms underpinning the biology of this disease and the development of safe and effective therapies.

STUDY DESIGN

Surgical human ACC specimens (UM-HACC-6, UM-HACC-14) were dissociated into single cell suspensions and cultured in fibronectin-coated flasks. Alternatively, tumor fragments were transplanted subcutaneously into female immunodeficient (SCID) mice to establish patient-derived xenograft tumors (PDX; UM-PDX-HACC-14).

RESULTS

Both ACC cell lines showed continuous growth in monolayers for over 100 passages. Total RNA-Seq, RT-PCR, and FISH analysis revealed that both are MYB-NFIB fusion negative. Western blots revealed passage-dependent expression of E-Cadherin, PCNA, p63, phospho-c-MYB, and NFIB. Both, UM-HACC-14 and UM-HACC-6 cells exhibited tumorigenic potential when injected orthotopically into mouse submandibular glands.

CONCLUSION

UM-HACC-14, patient-matching UM-PDX-HACC-14, and the UM-HACC-6 cell line are new, authenticated preclinical models of ACC that are well suited for mechanistic and developmental therapeutics studies.

Current Developments in Diagnosis of Salivary Gland Tumors: From Structure to Artificial Intelligence

Salivary glands tumors are uncommon neoplasms with variable incidence, heterogenous histologies and unpredictable biological behaviour. Most tumors are located in the parotid gland. Benign salivary tumors represent 54-79% of cases and pleomorphic adenoma is frequently diagnosed in this group. Salivary glands malignant tumors that are more commonly diagnosed are adenoid cystic carcinomas and mucoepidermoid carcinomas. Because of their diversity and overlapping features, these tumors require complex methods of evaluation. Diagnostic procedures include imaging techniques combined with clinical examination, fine needle aspiration and histopathological investigation of the excised specimens. This narrative review describes the advances in the diagnosis methods of these unusual tumors-from histomorphology to artificial intelligence algorithms.

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

BACKGROUND

Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs.

METHODS

We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma.

RESULTS

Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis.

CONCLUSIONS

Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

Intraosseous clear cell mucoepidermoid carcinoma: A case report and evaluation

Salivary gland tumours are relatively uncommon, and there exists a considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants, in addition to overlapping histological patterns similar to those observed in different tumour entities. One such group of variations is clear cell tumours of oral cavity which constitute an assorted group of lesions that may be odontogenic or metastatic or of salivary gland origin. The clear cell variant of mucoepidermoid carcinoma is at times misleading to the clinician because of its atypical location and innocent appearance. The pathologist needs to be familiar with the molecular alterations so that there may be a strong potential to implement good treatment. Hereby, we report a rare case of intraosseous clear cell variant of mucoepidermoid carcinoma which histopathologically posed challenges due to its variable presentation, suggesting the need for histochemical stains and molecular work-up for a definitive diagnosis and a better therapeutic and prognostic insight.

Mucoepidermoid carcinoma of the lower lip: A case report and review of literature

Mucoepidermoid carcinoma (MEC) is a rare salivary gland malignancy characterized by diverse cellular components. This case report presents a unique instance of low-grade MEC in a 28-year-old female, emphasizing the importance of accurate diagnosis and tailored management. The patient exhibited a painless, enlarging lower lip swelling over a year, with imaging suggestive of a fibrolipomatous lesion. Surgical excision was successfully performed, with subsequent histopathological analysis displaying mucinous cystic spaces, varied epithelial cell types and other characteristic features consistent with MEC. The case findings aligned with hallmark MEC features are seen in established literature, highlighting the significance of precise diagnosis and grading for appropriate management. This report contributes to the understanding of MEC's varied presentations and underscores the importance of thorough: histopathological examination, lower lip, mucoepidermoid carcinoma clinical evaluation, accurate histopathological analysis and interdisciplinary collaboration. The case highlights the value of considering MEC in younger patients, even with atypical presentations, and encourages ongoing exploration of diagnostic and therapeutic strategies to improve patient outcomes.

Surgical Treatment of Carcinomas of the Oral Minor Salivary Glands-Oncological Outcome in Dependence of Tumor Entity and Therapeutic Strategies

The aim of this study was to analyze the clinical outcomes of three types of minor salivary gland carcinomas (adenoid-cystic carcinomas (ACC), adeno carcinomas not otherwise specified (AC-NOS), and mucoepidermoid carcinomas (MEC)) after primary surgical therapy. A retrospective cohort study was designed and patients with cancer of the minor oral salivary glands treated in our department in the years 2011 to 2022 were included. Clinicopathological data were evaluated to compare overall survival and progression-free survival between the entities. Eighty-one patients were included. The rates of cervical metastases were 38.9% for ACC, 25% for MEC, and 9.1% for AC-NOS. ACC exhibited significantly higher rates of local and systemic disease recurrence (p = 0.02), and the presence of neck node metastases was confirmed as an independent prognostic factor for progression-free survival (p = 0.014). Treatment success in terms of oncological outcome varied significantly between the different entities and implies different treatment regimens for each tumor entity.

ACTH-secreting parotid acinic cell carcinoma unusually reported as a paraneoplastic syndrome

Paraneoplastic syndromes, induced by an immunological cross-reaction or hormone/peptide secretion, are an atypical presentation of tumors. Some tumors, such as small cell lung cancer and bronchial carcinoid, can be adrenocorticotropic hormone (ACTH) secreting tumors. Less commonly, parotid acinic cell carcinoma can be ACTH-secreting tumor leading to Cushing’s syndrome. Few literature cases have described ACTH related paraneoplastic syndrome of parotid adenocarcinoma. Because of the rarity of the condition, little is known about the management and prognosis of this phenomenon. In this report, we highlighted the case of a 59-year-old male with a past medical history of parotid adenocarcinoma treated with surgery, chemotherapy, and radiation therapy presented with clinical and biochemical signs of hyperaldosteronism. Abdominal ultra-sound, computed tomography, and magnetic resonance imaging showed hepatic mass. Liver biopsy with immunohistochemistry confirmed the presence of parotid adenocarcinoma secreting ACTH. He is on paclitaxel and carboplatin medication with good clinical response.

Notch signaling in oral pre-cancer and oral cancer

Notch signaling involves cell to cell contact. It is an ancient signaling mechanism that is conserved throughout the animal kingdom. The basic function of Notch signaling is to decide cell fate and execute asymmetrical division. Notch signaling is indispensable for embryo growth. Aberrant Notch signaling involves in cancer progression by altering cell proliferation rate, tumor micro-environment, stem cell activities. The role of Notch signaling in cancer progression is context-dependent. In breast cancer and T cell lymphoma Notch signaling is highly active, whereas in squamous cell carcinoma (SCC) as oral and skin cancer, the signaling is suppressed. It is believed that in SCC, Notch-mediated tumor growth is due to the cell non-autonomous function. Oral cancer is the 6th most risky cancer worldwide. In many patients, oral cancer is preceded by pre-cancer conditions. In this review, we have summarized the research knowledge related to the role of Notch signaling in oral cancer and pre-cancer conditions and the therapeutic options available targeting different components of Notch pathways.

Diagnostic utility of p63/p40 in the histologic differentiation of salivary gland tumors: A systematic review

OBJECTIVE

Salivary gland tumors are a heterogeneous group of neoplasms with complex clinicopathologic behavior. These tumors often show an extremely diverse morphology and significant histologic patterns, making diagnosis a difficult task. Owing to the considerable differences in prognosis, treatment, and follow-up, accurately distinguishing these histologic mimickers is imperative. The aim of the present systematic review was to establish the diagnostic utility of p63/p40 immunostaining in histologic differentiation of salivary gland tumors.

STUDY DESIGN

An electronic search was carried out using MEDLINE by PubMed, Scopus, Google Scholar, Trip, Cochrane Library, and EMBASE databases. Articles in which both p63 and p40 immunohistochemical expressions were assessed were included for systematic review and their sensitivity and specificity were calculated. Risk of bias was analyzed for each study using the Quality Assessment of Diagnostic Accuracy Studies tool.

RESULTS

Ten eligible articles were included in the quantitative synthesis, which revealed a concordant positivity of p63 and p40 by nearly all cases of adenoid cystic carcinoma, pleomorphic adenoma, and mucoepidermoid carcinoma and most polymorphous adenocarcinomas showed discordant immunohistochemical expression (p63+/p40-).

CONCLUSIONS

The current evidence supports that integrated immunostaining of p63/p40 is a valuable adjunct for discerning enigmatic salivary gland tumors with true myoepithelial and/or squamous differentiation.

Primary acinic cell carcinoma of mandible, report of a case and literature review

Introduction and importance

Acinic cell carcinoma (ACC) is a rare low-grade salivary gland malignancy that accounts for approximately 17% of all salivary gland malignancies. The most common site affected by ACC is the parotid gland followed by the submandibular glands, minor salivary glands, and sublingual glands. Also, it could hardly be observed in unusual sites such as the jaw bones.

Case presentation

This case is an example of a central acinic cell carcinoma in a 73-year-old man who came up with a painless gradual swelling for 15 months. Based on clinico-radio-pathologic findings, the diagnosis of a solid variant Intraosseous Acinic Cell Carcinoma was established. Subsequently, the patient underwent hemimandibulectomy and modified radical neck dissection, followed by postoperative radiotherapy. Within a six-month follow-up period, no evidence of residual tumor was found.

Clinical discussion

Central salivary gland carcinoma is a rare entity and intraosseous ACC is more scarcely observed. Based on our findings, a total of 17 cases of primary intraosseous ACC have been reported so far. Etiology and clinical presentations of this tumor are still vague due to its rarity.

Conclusion

Dentists and oral surgeons must be aware of such a rare malignant lesion when encountering a radiolucent lesion within the jaws. The early diagnosis and a complete surgical excision to achieve tumor-free surgical margins and a long-term follow-up could result in significantly improved survival rates.

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ACCs are a type of uncommon salivary gland tumors and the intra-osseous counterparts are extremely rare.

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Due to clinical and radiologic similarities to benign tumors, histopathologic and IHC findings should also be considered.

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Primary surgical design should be wide enough and en bloc resection should be suggested.

The potential of somatostatin receptor 2 as a novel therapeutic target in salivary gland malignant tumors

BACKGROUND

Treatment regimens for patients with metastatic or recurrent post-radiation, locoregional, unresectable salivary cancer are limited. An inverse correlation between somatostatin receptor 2 (SSTR2) and the proliferating marker Ki-67 in neuroendocrine tumors has enabled a treatment plan for metastatic disease, utilizing peptide receptor radionuclide therapy. Interestingly, healthy salivary glands express high levels of SSTR2. In this study, the presence of SSTR2, its correlation with Ki-67 in glandular salivary carcinomas and the clinical applicability thereof was determined.

METHODS

In the retrospective part of this study, 76 adequate tumor tissue specimens obtained from patients diagnosed with primary or metastatic salivary carcinomas between 1988 and 2016, were collected for tissue array and histologically classified. Immunohistochemistry was performed to determine the presence, relative expression and potential correlation of SSTR2 and Ki-67. The clinical significance of SSTR2 expression was determined by prospectively assessing ⁶⁸Ga-DOTATATE uptake using PET-CT imaging, in patients diagnosed with metastatic salivary gland malignant tumors between 2015 and 2016.

RESULTS

Sixty-three primary cancer tumors and 14 metastatic tumors were tested. All tumor subtypes were found to express SSTR2 to some extent. The highest expression was seen in Mucoepidermoid carcinoma (MEC) tissues where the majority of specimens (86.4%) expressed SSTR2. A relatively strong immunohistochemical staining score for SSTR2 was observed in MEC, adenoid cystic carcinoma and polymorphous adenocarcinoma. Interestingly, an inverse correlation between SSTR2 and Ki-67 expressions was observed (44%) in MEC tissue. Uptake of ⁶⁸Ga-DOTATATE was visualized using PET-CT imaging in 40% of patients, across metastatic MEC and ACC. All observations were found to be statistically significant.

CONCLUSION

This study confirms the expression of SSTR2 in glandular salivary carcinomas and an inverse correlation in expression levels between SSTR2 and Ki-67. This lays a foundation for novel treatment options in salivary metastatic cancers where SSTR2 may be a potential novel therapeutic target.

[Expression of thymidylate synthase in salivary adenoid myoepithelial cells and its clinical significance]

OBJECTIVE

To evaluate the expression of thymidylate synthase (TS) in myoepithelial cells (MECs) of salivary adenoid tissues and explore its clinical significance.

METHODS

Immunohistochemical staining EnVision method was used to detect the expression of TS, P63, Calponin, CK5/6 and S-100 in 32 salivary gland specimens, including 10 non-neoplastic and salivary inflammation specimens, 11 mixed tumor specimens, 5 basal cell carcinoma specimens and 6 adenoid cyst carcinoma specimens. The specificity and sensitivity of TS as a specific molecular marker of salivary muscle epithelial cells were evaluated in comparison with P63, Calponin, CK5/6 and S-100.

RESULTS

The expression pattern of TS in all the salivary gland tissue specimens was identical with that of p63. TS and P63 both showed strong immunohistochemical expressions in MECs of salivary adenoid tissue specimens. Calponin, CK5/6, and S-100 showed cytoplasmic/membranous expressions in the MECs. In addition, TS exhibited weak or moderate cytoplasmic expression in a few salivary gland epithelial cells, cancer cells and scattered stromal cells, with negative expression in the cell nuclei. The expression of TS in the MECs of all the salivary adenoid specimens was highly consistent with those of P63, Calponin, CK5/6 and S-100 (P>0.05) Except for CK5/6 expression in Salivary inflammation and Salivary gland specimens. Kappa>0.75. The specificity and sensitivity of TS as a molecular marker of MECs were both 100%.

CONCLUSIONS

TS is a new specific marker of MECs for differential diagnosis of salivary gland tumors.

Neck involvement and disease recurrence in adenoid cystic carcinoma of the minor salivary glands: the role of surgery in primary and progressive disease

The aim of this study was to analyse the rates of metastatic events and clinical outcomes of patients with adenoid cystic carcinoma (ACC) of the minor salivary glands and to critically evaluate the role of surgical therapy. A retrospective cohort study was designed including all patients with ACC of the oral minor salivary glands treated in the study department during the years 2010-2017. Relevant clinicopathological data were analysed to determine factors with an impact on overall survival (OS) and progression-free survival (PFS). Forty-one patients with primary ACC of the oral cavity and the oropharynx were included. Cervical metastases were found in 14 patients (34.1%) and were shown to have a significant negative impact on OS (P=0.009) and PFS (P=0.03). Sixteen patients developed disease recurrence during follow-up (39.0%) and most patients exhibited local disease recurrence with or without regional or distant metastases (14/16, 87.5%). Local recurrence was treated successfully with surgery in five cases. We recommend surgical therapy for patients with ACC of the minor salivary glands, including elective neck dissection and microvascular reconstruction, to optimize the planning of adjuvant therapy.

An In Vitro Barrier Model of the Human Submandibular Salivary Gland Epithelium Based on a Single Cell Clone of Cell Line HTB-41: Establishment and Application for Biomarker Transport Studies

The blood–saliva barrier (BSB) consists of the sum of the epithelial cell layers of the oral mucosa and salivary glands. In vitro models of the BSB are inevitable to investigate and understand the transport of salivary biomarkers from blood to saliva. Up to now, standardized, cell line-based models of the epithelium of the submandibular salivary gland are still missing for this purpose. Therefore, we established epithelial barrier models of the submandibular gland derived from human cell line HTB-41 (A-253). Single clone isolation resulted in five different clones (B2, B4, B9, D3, and F11). Clones were compared to the parental cell line HTB-41 using measurements of the transepithelial electrical resistance (TEER), paracellular marker permeability assays and analysis of marker expression for acinar, ductal, and myoepithelial cells. Two clones (B9, D3) were characterized to be of acinar origin, one clone (F11) to be of myoepithelial origin and one isolation (B4) derived from two cells, to be presumably a mixture of acinar and ductal origin. Clone B2, presumably of ductal origin, showed a significantly higher paracellular barrier compared to other clones and parental HTB-41. The distinct molecular identity of clone B2 was confirmed by immunofluorescent staining, qPCR, and flow cytometry. Experiments with ferritin, a biomarker for iron storage, demonstrated the applicability of the selected model based on clone B2 for transport studies. In conclusion, five different clones originating from the submandibular gland cell line HTB-41 were successfully characterized and established as epithelial barrier models. Studies with the model based on the tightest clone B2 confirmed its suitability for transport studies in biomarker research.

Role of Fine Needle Aspiration Cytology in the Diagnosis of Parotid Gland Tumors: Analysis of 193 Cases

Introduction  Parotid gland tumors include a wide variety of inflammatory and neoplastic diseases. The majority of these tumors are benign (80%), which usually require superficial parotidectomy, while the incidence of malignant tumors is lower (20%), requiring more radical surgery with or without neck dissection. The diagnosis cannot be established on the basis of clinical history and simple physical examination and requires complementary diagnostic methods. Fine needle aspiration cytology (FNAC) guided by ultrasound is a widely used diagnostic tool to evaluate parotid swellings. Objective  To determine the sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of FNAC in the diagnosis of parotid gland tumors. Methods  A retrospective chart review of 193 patients who underwent preoperative FNAC and parotidectomy at the Aga Khan University Hospital, Karachi, Pakistan, from the period of January 2000 to December 2015 was performed. Results  Out of 193 patients undergoing parotidectomy, 110 (57%) were males and 83 (43%) were females, the mean age being 48.21 and 43.76 years old, respectively. The mean duration of the symptoms was 41.33 months, and the most common symptom was preauricular swelling present in all patients, followed by pain, which was present in 29 patients (15%) and facial nerve weakness in 6 patients (3.1%). Fine needle aspiration cytology was performed preoperatively and the results were compared with the final histopathology, which showed sensitivity of 88.9%, specificity of 97.9%, positive predictive value of 93%, negative predictive value of 96.7% and diagnostic accuracy of 95.8%. Conclusion  Our results suggest that FNAC is relatively an accurate method for preoperative diagnosis of parotid swelling and can prove to be a valuable tool for preoperative counseling of the nature of the disease and prognosis.

Metastatic Acinic Cell Carcinoma to the Vagina: A First Reported Case

This is a case of a 62-year-old woman with a remote history of acinic cell carcinoma of the parotid gland, who presented with a palpable vaginal mass, anterior vaginal wall prolapse, and stress urinary incontinence. A 2 cm firm mobile mass on the anterior vaginal wall was found on clinical examination. A computed tomographic scan revealed a mass between the vaginal vault and bladder that was eventually surgically excised. The histology, supported by the immunohistochemistry, revealed metastatic acinic cell carcinoma to the vagina after 37 years of her initial diagnosis. This is the first reported case in the literature to occur in the vagina.

Parotid Gland Carcinoma Masquerading as an Aural Polyp

INTRODUCTION

Parotid gland squamous cell carcinoma is an uncommon aggressive neoplasm with poor prognosis. Aural polyps are usually the presenting features of chronic suppurative otitis media, tuberculous otitis media, and adenoma or carcinoma. The malignant aural polyp is very rare. Parotid gland carcinoma masquerading as an aural polyp has rarely been described in the literature.

CASE REPORT

We report a case study of parotid squamous cell carcinoma in a 29-year-old male masquerading as an ear polyp.

CONCLUSION

Parotid gland primary squamous cell carcinoma is a rapidly advancing neoplasm which carries poor prognosis despite multimodality treatment. Diligent clinical and histopathological evaluation is imperative to discriminate this rare aggressive disease from the metastatic and other primary cancers of the parotid. A high index of suspicion is crucial in refractory aural polyps to arrive at early diagnosis.

UM-HACC-2A: MYB-NFIB fusion-positive human adenoid cystic carcinoma cell line

OBJECTIVES

Limited availability of validated human adenoid cystic carcinoma (ACC) cell lines has hindered the mechanistic understanding of the pathobiology of this malignancy and the development of effective therapies. The purpose of this work was to generate and characterize a human ACC cell line.

MATERIAL AND METHODS

Immediately after surgery, a tumor fragment from a minor salivary gland from the tongue of a female Caucasian was minced, dissociated, and a single cell suspension was plated in fibronectin-coated flasks. A culture medium containing bovine brain extract and rhEGF was optimized for these cells. Whole exome sequencing was used to evaluate the presence of MYB-NFIB translocation.

RESULTS

The University of Michigan-Human Adenoid Cystic Carcinoma (UM-HACC)-2A cells showed continuous growth in monolayers for at least 180 in vitro passages while maintaining epithelial morphology. Short-tandem repeat (STR) profiling confirmed a 100% match to patient DNA. Whole exome sequencing revealed the presence of the MYB-NFIB fusion in UM-HACC-2A cells, which was confirmed by PCR analysis. Western blots revealed high expression of epithelial markers (e.g. E-cadherin, EGFR, pan-cytokeratin) and proteins associated with ACC (e.g. c-Myb, p63). Developmental therapeutic studies showed that UM-HACC-2A cells were resistant to cisplatin (IC₅₀ = 44.7 µM) while more responsive to paclitaxel (IC₅₀ = 0.0006 µM). In a pilot study, we observed that UM-HACC-2A cells survived orthotopic transplantation into the submandibular gland. Notably, one of the mice injected with UM-HACC-2A cells exhibited lung metastasis after 6 months.

CONCLUSION

UM-HACC-2A is a MYB-NFIB fusion-positive ACC cell line that is suitable for mechanistic and developmental therapeutics studies.

Characterisation of DOG-1 Expression in Salivary Gland Tumours and Comparison with Myoepithelial Markers

DOG1 is an established diagnostic marker for gastrointestinal stromal tumours (GIST), but has been reported in salivary gland tumours (SGT) as an acinar and intercalated duct marker. However, its specificity and distribution is not well established. The aim of this study was to evaluate the diagnostic utility of DOG-1 expression in SGT in addition to comparing it with myoepithelial markers. Normal salivary tissue and SGT (n = 184) were examined for expression of DOG1 and a range of myoepithelial markers. SGT included: acinic cell carcinoma (ACC, n = 15), secretory carcinoma (SC, n = 9), pleomorphic adenoma (PA, n = 49), carcinoma ex-PA (Ca ex-PA, n = 11), adenoid cystic carcinoma (AdCC, n = 20), polymorphous adenocarcinoma (PAC, n = 6), myoepithelioma (n = 6), myoepithelial carcinoma (MC, n = 2), basal cell adenoma (BCA, n = 14), canalicular adenoma (CA, n = 19), mucoepidermoid carcinoma (MEC, n = 11), oncocytoma (n = 2), adenocarcinoma NOS (AdNOS, n = 4), basal cell adenocarcinoma (BCAC, n = 2), salivary duct carcinoma (SDC, n = 3) and papillary cystadenocarcinoma (PCAC, n = 1). Normal acini and ACC (14/15) showed strong luminal DOG1 staining; SC were largely negative with only focal expression in 3/9 cases. Luminal staining was seen in PA (14/49), PAC (4/6), Ca ex-PA (4/11) and AdCC (6/20). 8/11 MEC showed luminal and/or mucous cell staining. No staining was seen in myoepithelioma, MC, CA, adNOS and BCAC. BCA showed strong staining of myoepithelial cells in some cases (5/14). Variable myoepithelial DOG1 staining was seen in PA, Ca ex PA, BCA, SDC and PCAC which was not as consistent as myoepithelial markers such as calponin, p63 and αSMA. Absence of DOG1 can differentiate ACC from SC, but staining is variable in PA, PLGA and Ca ex-PA. Myoepithelial staining in some tumours but not in normal gland suggests a wider distribution in SGT than originally envisaged.

AKT3 drives adenoid cystic carcinoma development in salivary glands

Salivary gland cancer is an aggressive and painful cancer, but a rare tumor type accounting for only ~0.5% of cancer cases. Tumors of the salivary gland exhibit heterogeneous histologic and genetic features and they are subdivided into different subtypes, with adenoid cystic carcinomas (ACC) being one of the most abundant. Treatment of ACC patients is afflicted by high recurrence rates, the high potential of the tumors to metastasize, as well as the poor response of ACC to chemotherapy. A prerequisite for the development of targeted therapies is insightful genetic information for driver core cancer pathways. Here, we developed a transgenic mouse model toward establishment of a preclinical model. There is currently no available mouse model for adenoid cystic carcinomas as a rare disease entity to serve as a test system to block salivary gland tumors with targeted therapy. Based on tumor genomic data of ACC patients, a key role for the activation of the PI3K-AKT-mTOR pathway was suggested in tumors of secretory glands. Therefore, we investigated the role of Akt3 expression in tumorigenesis and report that Akt3 overexpression results in ACC of salivary glands with 100% penetrance, while abrogation of transgenic Akt3 expression could revert the phenotype. In summary, our findings validate a novel mouse model to study ACC and highlight the druggable potential of AKT3 in the treatment of salivary gland patients.

Reoperation following the use of non-standardized procedures for malignant parotid tumors

Non-standardized or conservative procedures are employed when parotid tumors involving the facial nerve or parotid carcinoma are misdiagnosed as benign parotid tumors prior to or during surgery. Remedial measures are usually required when the pathological diagnosis of a malignant parotid tumor is confirmed following surgery. The aim of the present study was to systematically evaluate reoperation subsequent to treatment with non-standardized procedures for malignant parotid tumors, and to explore the preoperative diagnoses, the primary procedure selection and the necessity of reoperation following non-standardized procedures in malignant parotid tumors. A total of 30 patients who met the inclusion criteria, were diagnosed with a malignant parotid tumor and underwent reoperation following the use of a non-standardized procedure were included in the present study. Surgical conditions and clinical data were analyzed. Among the patients with a malignant parotid tumor who underwent reoperation subsequent to a non-standardized procedure, the incidence of residual tumor, as confirmed by pathological examination, was 63.3% (19/30). The intact facial nerve preservation rate was 83.3% (25/30), the facial nerve branch resection rate was 6.7% (2/30), the facial partial nerve resection rate was 6.7% (2/30) and the facial nerve resection rate was 3.3% (1/30). In total, 3 patients underwent facial nerve reconstruction, 3 patients underwent a local flap repair of skin defects in the parotid region and 3 patients underwent pectoralis major muscle flap repair. The current findings indicate that the qualitative diagnosis of malignant parotid tumors prior to surgery is difficult, there is a high incidence of residual tumor following non-standardized procedures, and that reoperation in a timely manner is required in such cases.

Tumor Differentiation as a Prognostic Factor for Major Salivary Gland Malignancies

Objective The effect of tumor differentiation on prognosis of major salivary gland malignancies is controversial. The aim of this study was to determine the effect of tumor differentiation on prognosis by stage in patients with major salivary gland malignancies and to analyze which patient factors are associated with tumor differentiation. Study Design and Setting Cross-sectional analysis of Surveillance, Epidemiology, and End Results (SEER) database. Subjects and Methods In total, 9810 patients who had a major salivary gland malignancy from 2004 to 2012 were identified using the SEER database. Patients with no staging information or no information on histologic differentiation were excluded. A total of 5366 patients were included in the study. For analysis, patients were categorized by American Joint Committee on Cancer (AJCC) stage and subdivided by tumor differentiation. Multivariate analysis was used to analyze the impact of tumor differentiation on survival, tumor location (parotid, submandibular, sublingual), and sex within each AJCC stage of disease. Results Data analysis demonstrated a significant difference in histologic differentiation by stage, with P < .0001. Within stages II, III, and IV, tumor differentiation was significantly associated with a decrease in survival. There was no significant difference in tumor differentiation between the parotid and submandibular gland. Conclusion For patients with stage II, III, and IV disease, tumor differentiation was an independent predictor of survival. This information can be useful when discussing prognosis and can potentially influence management of disease.

Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland

Malignant parotid tumors are heterogeneous and diverse. Accurate diagnosis requires a pathologist familiar with the various histologic subtypes, immunohistochemistry stains, and common translocations. Clinical course varies according to tumor subtype, ranging from indolent, slow-growing adenoid cystic carcinoma to rapidly progressive, possibly fatal, salivary ductal carcinoma. Histologic grade is important in prognosis and therapy. Surgery remains the mainstay of treatment when negative margins can be achieved. Radiation improves locoregional control of tumors with high-risk features. Chemotherapy for parotid tumors can be disappointing. Studies of new targeted therapies have not offered significant benefits.

Cutaneous Metastasis of a Mucoepidermoid Carcinoma of the Pancreas: First Reported Case

BACKGROUND

Mucoepidermoid pancreatic cancer is a rare entity with only 8 cases reported in the literature. On review of the literature, the authors found that cutaneous metastases in pancreatic cancer are rare and have not been associated with the mucoepidermoid subtype. The authors present the first reported case of cutaneous metastasis in a patient with mucoepidermoid carcinoma of the pancreas.

CASE PRESENTATION

A 50-year old white male with a metastatic invasive poorly differentiated mucoepidermoid carcinoma of the pancreas was found to have a slow growing lesion in the skin over his left upper quadrant while undergoing active therapy. The lesion was biopsied and the pathology was consistent with pancreatic origin sharing similar morphologic features when compared with the primary pancreactectomy specimen.

CONCLUSIONS

Mucoepidermoid pancreatic cancer is an exceedingly rare subtype of pancreatic cancer, with very little information regarding its diagnosis, treatment, and patterns of metastases. Here, the authors present the first reported case of cutaneous metastases of mucoepidermoid pancreatic cancer.

Cytokeratin immunoprofile of primary and metastatic adenoid cystic carcinoma of salivary glands: a report of two cases

Distant metastases from salivary gland tumors are considered infrequent: the incidence of distant metastases ranges from 24% to 61% according to different histotypes and to the site of the primary mass. The most common site of distant metastases due to salivary gland malignancies is the lung. From the pathology point of view, cytokeratins (CK) are important differentiation markers in salivary gland tumors, which are often used for the diagnostic process. Their employment also may be useful to identify and confirm the diagnosis of their distant metastases. We report the expression of CK in two cases of primary and metastatic adenoid cystic carcinoma (ACC) and their CK profiles of the primary and metastatic masses. Both patients—one male and one female—were diagnosed with an ACC cribriform and tubular, respectively, with lung metastases. In case 1, the metastatic mass presented the same histotype and CK profile of the primary tumor. For case 2, the metastatic lung mass was distinct from the primary mass (a solid ACC) and presented a different CK profile. Although salivary gland metastatic disease presents a poor prognosis, both patients reported herein are alive despite the presence of the disease in long-term follow-up. Therefore, the modifications seen in the CK profiles do not appear to be predictive of tumor behavior and outcome. The use of a CK profile seems to be useful to identify the nature of a distant mass and its possible correlations with a primary salivary gland tumor.

Sore or Swollen Lips Part 2: Systemic Causes

This series of three papers reviews the causes, diagnosis and differential diagnosis, and outlines the management of sore and/or swollen lips. Clinical relevance: Sore and/or swollen lips are not uncommon, often have a local cause, but may reflect a systemic disease. The previous article reviewed important causes, from actinic to contact cheilitis, while this paper starts with drug-induced cheilitis and completes that alphabetical list.

Fine-Needle Aspiration Biopsy of Salivary Gland Lesions

CONTEXT

Fine-needle aspiration (FNA) is a well-established diagnostic approach for salivary gland lesions; however, lack of a standard system of terminology for classification of salivary gland neoplasms collected by FNA and the relatively high frequency of uncertainty of diagnosis are likely partly responsible for current confusion in the interpretation of these FNA samples.

OBJECTIVE

To propose a novel classification system for reporting salivary gland FNA samples and summarize recent progress in application of molecular and immunohistochemical markers in selected salivary gland neoplasms.

DATA SOURCES

Literature review and authors' personal practice experience.

CONCLUSIONS

The new classification system provides a more succinct, standardized interpretation of results and will ultimately assist in communication between clinicians, clinical decision making, and preoperative patient counseling. Impressive advances have been made in recent years in the understanding of molecular pathogenesis of salivary gland tumors. With the newly acquired diagnostic tools, significant improvement in diagnostic accuracy of salivary gland FNA can certainly be expected.

Adenoid basal cell carcinoma: a rare facet of basal cell carcinoma

Basal cell carcinoma (BCC) is a common, locally invasive epithelial malignancy of skin and its appendages. Every year, close to 10 million people get diagnosed with BCC worldwide. While the histology of this lesion is mostly predictable, some of the rare histological variants such as cystic, adenoid, morpheaform, infundibulocystic, pigmented and miscellaneous variants (clear-cell, signet ring cell, granular, giant cell, adamantanoid, schwannoid) are even rarer, accounting for <10% of all BCC's. Adenoid BCC (ADBCC) is a very rare histopathological variant with reported incidence of only approximately 1.3%. The clinical appearance of this lesion can be a pigmented or non-pigmented nodule or ulcer without predilection for any particular site. We share a case report of ADBCC, a rare histological variant of BCC that showed interesting features not only histologically but also by clinically mimicking a benign lesion.

Gingival fibromatosis: clinical, molecular and therapeutic issues

Gingival fibromatosis is a rare and heterogeneous group of disorders that develop as slowly progressive, local or diffuse enlargements within marginal and attached gingiva or interdental papilla. In severe cases, the excess tissue may cover the crowns of the teeth, thus causing functional, esthetic, and periodontal problems, such as bone loss and bleeding, due to the presence of pseudopockets and plaque accumulation. It affects both genders equally. Hereditary, drug-induced, and idiopathic gingival overgrowth have been reported. Hereditary gingival fibromatosis can occur as an isolated condition or as part of a genetic syndrome. The pathologic manifestation of gingival fibromatosis comprises excessive accumulation of extracellular matrix proteins, of which collagen type I is the most prominent example. Mutation in the Son-of-Sevenless-1 gene has been suggested as one possible etiological cause of isolated (non-syndromic) hereditary gingival fibromatosis, but mutations in other genes are also likely to be involved, given the heterogeneity of this condition. The most attractive concept of mechanism for drug-induced gingival overgrowth is epithelial-to-mesenchymal transition, a process in which interactions between gingival cells and the extracellular matrix are weakened as epithelial cells transdifferentiate into fibrogenic fibroblast-like cells. The diagnosis is mainly made on the basis of the patient's history and clinical features, and on histopathological evaluation of affected gingiva. Early diagnosis is important, mostly to exclude oral malignancy. Differential diagnosis comprises all pathologies in the mouth with excessive gingival overgrowth. Hereditary gingival fibromatosis may present as an autosomal-dominant or less commonly autosomal-recessive mode of inheritance. If a systemic disease or syndrome is suspected, the patient is directed to a geneticist for additional clinical examination and specialized diagnostic tests. Treatments vary according to the type of overgrowth and the extent of disease progression, thus, scaling of teeth is sufficient in mild cases, while in severe cases surgical intervention is required. Prognosis is precarious and the risk of recurrence exists.

The structure and function of NKAIN2-a candidate tumor suppressor

The deletion of chromosomal region 6q was commonly found in several types of human cancers, although the tumor suppressor genes (TSGs) located within this genomic region are not well established. Our recent work detected recurrent chromosomal truncation at the Na(+)/K(+) transporting ATPase interacting 2 (NKAIN2) gene in prostate cancer, which was also found to be truncated in leukemia and lymphoma, suggesting that NKAIN2 is potentially one of the TSGs located in the 6q commonly deleted region in human cancers. NKAIN2 gene consists of eight coding exons that span approximately 1 Mb of genomic DNA on chromosome 6q and there are four main splice variants. The function of this gene is not well investigated and the limited knowledge of this gene pointed to nervous system development. The chromosomal translocations in nervous development disorders usually lead to inactivation of this gene. In human tumors, both chromosomal deletion and translocation may also inactivate this gene and consequently contribute to tumorigenesis. Further genetic and cellular functional studies are required to establish its tumor suppressor role.