Assessment of p63 expression in the salivary gland neoplasms adenoid cystic carcinoma, polymorphous low-grade adenocarcinoma, and basal cell and canalicular adenomas

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

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

Liquid-based cytology (LBC) with immunocytochemical staining improves fine-needle aspiration cytology (FNA) performance for salivary gland tumors

BACKGROUND

Liquid-based cytology (LBC), now used globally for the head and neck region, has been used at our hospital since 2011. This study was designed to analyze the efficacy of LBC with immunocytochemical staining on preoperative diagnosis of salivary gland tumors.

METHODS

This retrospective analysis of fine-needle aspiration (FNA) performance for salivary gland tumors was conducted at Fukui University Hospital. Salivary gland tumor operations conducted during April 2006 - December 2010 (84 cases) were classified as the Conventional Smear (CS) group, which were diagnosed morphologically by Papanicolaou and Giemsa staining. Those done during January 2012 - April 2017 (112 cases) were classified as the LBC group, which were diagnosed using LBC samples with immunocytochemical staining. The FNA results and pathological diagnosis of both groups were analyzed to calculate the FNA performance.

RESULTS

Compared to the CS group, cases of inadequate and indeterminate FNA sample were not reduced significantly by LBC with immunocytochemical staining. As for FNA performance, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CS group were, respectively, 88.7%, 53.3%, 100%, 100%, and 87.0%. Those of LBC group were all 100%, representing significant improvement over the CS group.

CONCLUSIONS

Analysis results indicated the usefulness of LBC with immunocytochemical staining for preoperative diagnosis of salivary gland tumors.

Comparison of Diagnostic Reliability of p63 and Smooth Muscle Actin in Salivary Gland Neoplasms

Salivary gland neoplasms pose considerable diagnostic difficulty owing to their diverse histological features in individual lesions and the presence of a number of types and variants & similar histological features with other tumor entities. Myoepithelial and basal cells play a significant role in the pathogenesis of salivary gland neoplasm. p63 and smooth muscle actin are more reliable markers for identifying these cells and not studied much comparing their reliability in the diagnosis of salivary gland neoplasms. Hence, the aim of this study is to evaluate and compare the diagnostic reliability of immunohistochemical markers such as p63 and smooth muscle actin (SMA) in the diagnosis of various benign and malignant salivary gland neoplasms. The study comprises of 18 samples categorized into two groups: Group I comprised 9 cases, of which 4 cases were Pleomorphic adenoma, 2 cases were Myoepithelioma, 2 cases of Basal cell adenoma and 1 case was Warthin's tumor; and Group II consisted of 9cases, of which 3 was Mucoepidermoid carcinoma, 1 cases were Myoepithelial carcinoma and 5 cases were Adenoid cystic carcinoma. The selected cases were subjected to immunohistochemistry (IHC) procedure to assess the expression pattern of p63 and smooth muscle actin. The obtained data was analysed statistically by using Mann-Whitney test. In SMA, strong positivity for epithelial and connective tissue components of benign salivary neoplasm is about 22.2%respectively. In malignant salivary neoplasm, SMA was strongly positive for the epithelial and connective tissue component of about 77.7% and 88.8% cases respectively. The difference in the connective tissue components was found to be statistically significant (U = 24, P = 0.032). P63 was strongly positive for the epithelial and connective tissue component of benign salivary neoplasm of about 33.3% and 11.1% cases respectively.In malignant salivary neoplasm, p63 was strongly positive for the epithelial component of about 66.6% cases and connective tissue is completely negative. Alpha-SMA can be utilized as reliable IHC markers for salivary gland neoplasms due to its diagnostic importance in tumors with myoepithelial origin indicative of the histogenesis of salivary gland tumors and even p63 can be used as specific markers for differentiation of malignant salivary gland tumors.

Immunohistochemical Profile of Polymorphous Adenocarcinoma of Minor Salivary Gland: A Systematic Review and Meta-Analysis

Polymorphous adenocarcinoma (PAC) is a rare variant of minor salivary gland tumors. Because of its architectural diversity, histological diagnosis of PAC can be difficult especially for small biopsies, and immunohistochemistry is of great help in differentiating it from its histologic mimics. The aim of this study is to conduct a systematic literature review to identify reliable immunohistochemical markers for PAC. We conducted an electronic literature search of the MEDLINE, ScienceDirect, SpringerLink, and Wiley Online Library databases, covering the literature published in the period between 1988 and 2021. The eligibility criteria included case reports and retrospective studies of PAC cases with details of immunohistochemical markers. Following the search and selection process, 32 studies with 409 cases were included in this systematic review. Overall, > 90% positivity was observed for pan-cytokeratin (CK) (97.3%), CK7 (96.8%), CK7/8 (97.4%), E-cadherin (90.0%), Vimentin (92.5%), S100 (97.0%), p63 (91.7%), and SOX10 (100%), while little to no positivity was observed for CK20 (0.0%), p40 (0.0%), and GFAP (5.0%). The average MIB-1 labeling index was 3.78%. The results of this systematic review indicate that CK7+/CK20-, p63+/p40-, S100+, Vimentin+, and GFAP- immunophenotype have diagnostic value for PAC. In addition, the use of S100, MSA, p40, and c-Kit provide additional layers of information helpful to differentiate PAC from adenoid cystic carcinoma, one of challenging differential diagnoses.

Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors

Background

The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT.

Methods

Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software.

Results

The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly.

Conclusion

In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results.

Basal Cell Adenoma and Basal Cell Adenocarcinoma

Basal cell adenoma (BCA) and basal cell adenocarcinoma (BCAC) are uncommon biphasic salivary gland tumors having morphologic similarities to other biphasic salivary gland neoplasms having differentiation toward the intercalated ducts of the salivary gland. Both tumors show mixtures of trabecular, tubular, solid, and membranous solid patterns. BCAC is separated from BCA primarily by the presence of invasion in the former. The diagnosis of BCA and BCAC is best carried out with hematoxylin and eosin-stained sections and careful attention to detail of tumors in the differential diagnosis, including adenoid cystic carcinoma, pleomorphic adenoma, and epithelial myoepithelial carcinoma.

Microsecretory adenocarcinoma of the hard palate: A case report of a recently described entity

We report a case of microsecretory adenocarcinoma of the hard palate. The patient is a 37-year-old woman with a 15 mm submucosal tumor, which was incidentally found by her primary care dentist, in her hard palate. Preoperative magnetic resonance imaging revealed a tumor exhibiting high signal on T2-weighted image, which was gradually enhanced on dynamic study. Histologically, the tumor border was ill-defined without fibrous capsule and adjoined minor salivary gland with permeative infiltration at the tumor periphery. The tumor comprised intercalated duct-like cells with polygonal narrow eosinophilic to clear cytoplasm and small, uniform oval nuclei. These cells formed small infiltrative microcysts, tubules and fascicular cords collecting pale basophilic secretions and small vacuoles setting in an abundant fibromyxoid stroma. The tumor cells were positive for CK AE1+AE3, S-100 protein, and p63, while are completely negative for p40, alpha-SMA, and calponin. The MEF2C-SS18 fusion was identified by reverse transcriptase-polymerase chain reaction followed by Sanger sequencing. The combination of characteristic histology, immunophenotype, and presence of MEF2C-SS18 fusion indicated the diagnosis of microsecretory adenocarcinoma of the hard palate, an entity described only recently. Post-operative course was uneventful and there was no evidence of disease at 4 months after surgery.

First description of basaloid carcinoma of the canine mammary gland: case report

ABSTRACT The objective of this case report was to describe histopathological and immunohistochemical characteristics of the first reported basaloid carcinomas in the canine mammary gland. Two bitches were treated for tumors in the mammary gland and underwent mastectomy. Microscopic evaluation of these tumors revealed epithelial cells arranged in a predominantly solid pattern with hyperchromatic peripheral cells arranged in a palisade pattern. Metastases in regional lymph nodes were found in both animals, and one bitch exhibited pulmonary metastasis. Immunohistochemistry revealed positive labeling for the basal cell markers cytokeratin 14 and p63. Histopathological and immunohistochemical findings led to diagnoses of basaloid carcinoma of the canine mammary gland with regional and distant metastasis.

Salivary gland stem cells: A review of development, regeneration and cancer

Salivary glands are responsible for maintaining the health of the oral cavity and are routinely damaged by therapeutic radiation for head and neck cancer as well as by autoimmune diseases such as Sjögren's syndrome. Regenerative approaches based on the reactivation of endogenous stem cells or the transplant of exogenous stem cells hold substantial promise in restoring the structure and function of these organs to improve patient quality of life. However, these approaches have been hampered by a lack of knowledge on the identity of salivary stem cell populations and their regulators. In this review we discuss our current knowledge on salivary stem cells and their regulators during organ development, homeostasis and regeneration. As increasing evidence in other systems suggests that progenitor cells may be a source of cancer, we also review whether these same salivary stem cells may also be cancer initiating cells.

Immunohistochemical evaluation of p63 and cyclin D1 in oral squamous cell carcinoma and leukoplakia

Objectives

There are only a limited number of studies on cyclin D1 and p63 expression in oral squamous cell carcinoma (OSCC) and leukoplakia. This study compared cyclin D1 and p63 expression in leukoplakia and OSCC to investigate the possible correlation of both markers with grade of dysplasia and histological grade of OSCC.

Materials and Methods

The study included a total of 60 cases, of which 30 were diagnosed with OSCC and 30 with leukoplakia, that were evaluated immunohistochemically for p63 and cyclin D1 expression. Protein expression was correlated based on grades of dysplasia and OSCC.

Results

Out of 30 cases of OSCC, 23 cases (76.7%) were cyclin D1 positive and 30 cases (100%) were p63 positive. Out of 30 cases of leukoplakia, 21 cases (70.0%) were cyclin D1 positive and 30 (100%) were p63 positive (P<0.05).

Conclusion

The overall expression of cyclin D1 and p63 correlated with tumor differentiation, and increases were correlated with poor histological grades, from well-differentiated to poorly-differentiated SCC. Increased cyclin D1 and p63 expression was associated with the severity of leukoplakia. Based on these results cyclin D1 and p63 products can be a useful tool for improved leukoplakia prognosis.

Canalicular adenoma: A systematic review

OBJECTIVE

Canalicular adenoma (CA) is an uncommon but unique benign tumor of salivary gland origin. It is the third most common benign tumor of minor salivary glands, representing less than 1% of all salivary neoplasms. A systematic review is presented of reported cases of CA, to determine trends in presentation, diagnostic features, treatment, and patient outcome.

METHODS

Searches of specific databases, as reported, were carried out to identify papers reporting CA. The variables were patient symptoms, tumor location, histopathological findings, demographics, treatment, follow-up, and recurrence.

RESULTS

430 cases were identified; the most common location was in the upper lip (66.3%), followed by hard palate (14.5%). The most common clinical presentation was a nodule (46.5%), followed by asymptomatic (29.5%), and discomfort (28.7%). CA was most frequently seen in females (64%). The average age was 66.3 years. 97% of cases were treated surgically. The average follow-up was 136.3 months, and recurrence was reported in 3% of the cases.

CONCLUSION

CA shows a strong predilection for the upper lip. CAs are frequently asymptomatic, but the principal symptom was pressure.

Plasmacytoid-Type Cellular Differentiation in Polymorphous Low-Grade Adenocarcinoma

INTRODUCTION

Polymorphous low-grade adenocarcinoma (PLGA) occurs more frequently in minor salivary glands. The diagnosis of PLGA, in general, is not difficult but in occasional tumors showing limited invasion or in small biopsy specimens, PLGA may be confused with cellular pleomorphic adenoma (PA). Plasmacytoid cells, a usual component of PAs, have been considered helpful for correct tumor identification.

OBJECTIVE

The aim of this study was to verify the frequency (if any) of plasmacytoid-type cellular differentiation (PD) in PLGA.

MATERIALS AND METHODS

Thirty-two cases of PLGA were reviewed. PD was recognized in 2 cases (6.25%), in which immunohistochemical expression of AE1/AE3, CK7, CK14, vimentin, α-SMA, p63, S-100, calponin, GFAP, and Ki-67 was evaluated.

RESULTS

The 2 cases presented conventional areas of PLGA and variable quantities of cells with PD forming aggregates in the stroma and lining ductal structures. Cells with PD showed positivity for AE1/AE3, CK7, S-100, and vimentin and were negative for CK14, calponin, and GFAP in both cases. In case 1, cells with PD did not present α-SMA and p63 positivity whereas in case 2 they were positive, but for α-SMA such reactivity was restricted to cells forming solid aggregates.

CONCLUSION

Although PD in PLGA is rare, it is necessary to be aware of this possibility, particularly in small incisional biopsies and in PLGA with limited invasion, to avoid confusion with cellular PA.

Polymorphous low-grade adenocarcinoma of the epiglottis: A case report

Polymorphous low-grade adenocarcinoma is an uncommon malignant tumor derived from the terminal duct cells of the salivary glands. The present study described a rare case of polymorphous low-grade adenocarcinoma, T2N0M0 stage 2, in a 65-year-old man, who presented with a sore throat and painful dysphagia. Computed tomography revealed an infiltrative heterogenous enhancing mass involving the left aryepiglottic fold. He underwent a tumor removal with frozen section for evaluating the surgical margin. Subsequent supraglottic laryngectomy was performed. Polymorphous low-grade adenocarcinoma was diagnosed histologically, characterized by cytologic uniformly, morphologic diversity and an infiltrative growth pattern. Epiglottic cartilaginous invasion by the tumor is demonstrated. Clinical, radiological, endoscopic and pathological features with briefly reviewed relevant literatures are discussed. This is the first reported description in the literature, to the best of our knowledge, of an epiglottic polymorphous low-grade adenocarcinoma receiving successful supraglottic laryngectomy with 7 year disease free survival.

Ongoing challenges in the treatment of adenoid cystic carcinoma of the head and neck

BACKGROUND

Adenoid cystic carcinoma is a malignant tumour of major and minor salivary glands. Distant metastasis and poor survival are persistent in the literature, with recent publications aimed at understanding molecular pathogenesis and development of pharmaceutical therapeutic options.

AIM

Provide an update of recent studies in the management of adenoid cystic carcinoma of the head and neck.

METHODS

Literature search using Medline, Scopus, Google Scholar, the Cochrane Database of Systematic Reviews and the Cochrane central register of controlled trials for articles on adenoid cystic carcinoma from January 2005 to January 2015.

CONCLUSION

Adenoid cystic carcinoma is characterized by a slow growing mass, with distant metastasis independent of local or regional control. Primary tumour resection remains the preferred option with radiotherapy having an adjuvant role. Recent advances have been made with novel targeted therapies however, limited to clinical trials and advanced disease.

Review and Updates of Immunohistochemistry in Selected Salivary Gland and Head and Neck Tumors

Context

Immunohistochemistry is a useful tool for diagnosing salivary gland and head and neck tumors.

Objective

To review immunohistochemical markers, which can aid in the diagnosis of selected salivary gland and head and neck tumors.

Data Sources

Literature review and authors' personal practice experience.

Conclusions

Salivary gland and head and neck tumors include a large diverse group of tumors with complex and overlapping histologic features. Immunohistochemistry plays an important role in resolving the differential diagnosis of some salivary gland and head and neck tumors and can provide information for the prognosis of certain tumors.

Fatty Acid binding protein 7 is a molecular marker in adenoid cystic carcinoma of the salivary glands: implications for clinical significance

Adenoid cystic carcinoma (ACC) is an aggressive malignant neoplasm of the salivary glands. Its diagnosis is difficult due to overlapping features with other salivary tumors. Gene expression analysis may complement traditional diagnostic methods. We searched gene expression patterns in the Gene Expression Omnibus (GEO) database and in our tumor and normal samples. The biologic and prognostic potential of the identified genes was analyzed. The GEO data set of primary xenografted ACCs revealed that expression of five genes, engrailed homeobox 1 (EN1), fatty acid binding protein 7 (FABP7), hemoglobin epsilon 1, MYB, and versican (VCAN), was dramatically increased. mRNA expression of EN1, FABP7, MYB, and VCAN distinguished our sporadic ACCs from normal tissues and benign tumors. FABP7 expression appeared to be regulated differently from EN1 and MYB and was crossly correlated with poor prognosis in our ACC cohort. Immunohistochemistry showed that FABP7 protein was predominantly expressed in the nucleus of myoepithelial cells of both tubular and cribriform subtypes. In contrast, in the solid subtype, which is often associated with a lower survival rate, FABP7 protein was uniformly expressed in cancerous cells. One case with cribriform architecture and the highest level of FABP7 mRNA showed strong FABP7 staining in both duct-type epithelial and myoepithelial cells, suggesting that diffuse expression of FABP7 protein might be related to aggressive tumor behavior and poor prognosis. We propose FABP7 as a novel biomarker in ACC. The molecule may be useful in diagnosis and for identifying more effective therapies targeting this protein or upstream molecules that regulate it.

Canalicular adenoma: a clinicopathologic and immunohistochemical analysis of 67 cases with a review of the literature

There is a lack of a comprehensive immunohistochemical (IHC) analysis of canalicular adenoma (CanAd), especially when combined with a description of the unique histologic features. Given the usual small biopsies, IHC may be useful in distinguishing CanAd from other tumors in the differential diagnosis. Retrospective. The patients included 54 females and 13 males (4.2:1), aged 43-90 years, with a mean age at presentation of 69.9 years. Clinical presentation was generally a mass (n = 61) slowly increasing in size (mean 38.5 months), affecting the upper lip (n = 46), buccal mucosa (n = 17) or palate (n = 4), involving the right (n = 29), left (n = 24) or midline (n = 9), without any major salivary gland tumors. The tumors ranged in size from 0.2 to 3 cm (mean 1.2 cm). Most tumors were multilobular or bosselated (76 %), often surrounded by a capsule. Histologically, the tumors were characterized by cystic spaces, tumor cords with beading, tubule formation, and by the presence of luminal squamous balls (n = 41). The cells were cuboidal to columnar with stippled chromatin. Mitoses were inconspicuous. A myxoid stroma (n = 64), sclerosis (n = 42), luminal hemorrhage (n = 51), and luminal microliths (calcifications) (n = 33) were characteristic. Nine (13.4 %) were multifocal. CanAd showed the following characteristic immunohistochemistry findings: CK-pan and S100 protein (strong, diffuse reaction); peripheral or luminal GFAP reaction; CK5/6 and p16 luminal squamous ball reaction; SOX10 nuclear reaction; cytoplasmic p63 reaction. CanAd are unique minor salivary gland tumors showing a distinct architecture and phenotype. They predilect to older women, with the majority multilobulated and affecting the upper lip, multifocal in 13 %; no major salivary gland tumors were identified. S100 protein, CK-pan, GFAP and SOX10 are positive, with luminal squamous balls highlighted by CK5/6 or p16.

Expression and localization of osteopontin, homing cell adhesion molecule/CD44, and integrin αvβ3 in pleomorphic adenoma, polymorphous low-grade adenocarcinoma, and adenoid cystic carcinoma

OBJECTIVES

Osteopontin (OPN) plays a role in tumor progression. This study aimed to determine the expression of OPN, CD44, and integrin αvβ3 in pleomorphic adenoma (PA), polymorphous low-grade adenocarcinoma (PLGA), and adenoid cystic carcinoma (ACC).

STUDY DESIGN

Immunohistochemistry was used to semiquantify the level of expression of OPN and its receptors in normal salivary glands (NSG; n = 20), PA (n = 20), PLGA (n = 16), and ACC (n = 22).

RESULTS

OPN expression was increased in PLGA and intermediate-/high-grade ACC compared with PA and NSG (median scores, 6, 5, 4, and 4, respectively). CD44 expression was reduced in PA, PLGA, and ACC. OPN expression levels were moderately correlated with CD44 in PLGA. Integrin αvβ3 was not expressed in PA and ACC and was seen in only 1 case of PLGA.

CONCLUSIONS

OPN is expressed in salivary gland tumors but does not correlate well with CD44 and αvβ3.

Polymorphous low grade adenocarcinoma has a consistent p63+/p40- immunophenotype that helps distinguish it from adenoid cystic carcinoma and cellular pleomorphic adenoma

Polymorphous low grade adenocarcinoma (PLGA) is a tumor of minor salivary glands that exhibits considerable morphologic overlap with adenoid cystic carcinoma and cellular pleomorphic adenoma, especially in small biopsy specimens. Unlike these other tumor types. PLGAs do not harbor a myoepithelial component, yet their frequent positivity for p63 diminishes the usefulness of this particular myoepithelial marker as a discriminating immunostain. p40 is an antibody that recognizes ΔNp63, a p63 isoform that is more specific for true myoepithelial differentiation. As such, p40 immunostaining could help distinguish PLGAs from adenoid cystic carcinomas and pleomorphic adenomas. In this study, p63 and p40 immunohistochemistry was performed on paraffin embedded, formalin fixed tissue from 11 PLGAs, 101 adenoid cystic carcinomas, and 31 pleomorphic adenomas. All 11 PLGAs (100 %) were positive for p63 but completely negative for p40. Among adenoid cystic carcinomas, 91 of 101 (90 %) were positive for p63 and 90/101 (89 %) were positive for p40. The single discordant p63+/p40- adenoid cystic carcinoma exhibited solid architecture and high grade features not typically seen in PLGA. Among pleomorphic adenomas, 21/31 (68 %) were positive for p63 and 13/31 (42 %) were positive for p40. For the pleomorphic adenomas, the discordant p63+/p40- staining pattern was seen only in the overtly mesenchymal chondromyxoid stroma. The cellular epithelial component of the pleomorphic adenomas demonstrated concordant p63+/p40+ or p63-/p40- immunophenotypes. PLGA consistently exhibits a p63+/p40- immunophenotype that can help distinguish it from adenoid cystic carcinoma and cellular pleomorphic adenoma, tumors that characteristically demonstrate concordant p63 and p40 immunostaining patterns. A p63/p40 immunohistochemical panel can provide a valuable tool for making the distinction between these morphologically similar but clinically divergent entities.

Expression and localization of osteopontin, homing cell adhesion molecule/CD44, and integrin αvβ3 in mucoepidermoid carcinoma and acinic cell adenocarcinoma of salivary gland origin

OBJECTIVE

Osteopontin (OPN) plays a role in tumor progression. This study aimed to determine the expression of OPN, CD44, and integrin αvβ3 in pleomorphic adenoma (PA), acinic cell adenocarcinoma (ACA), and mucoepidermoid carcinoma (MEC).

STUDY DESIGN

Immunohistochemistry was used to semiquantify the levels of expression of OPN and its receptors in normal salivary glands (NSG) (n = 20), PA (n = 20), ACA (n = 11), and MEC (n = 29).

RESULTS

OPN expression was increased in ACA and MEC compared with PA and NSG (median scores, 6, 6, 4, and 4, respectively). CD44 expression was increased in ACA and reduced in MEC and PA compared with NSG (median scores, 8, 4, 3, and 5, respectively). Integrin αvβ3 median scores were 5 in ACA, 1 in MEC, and 0 in PA and NSG.

CONCLUSIONS

OPN is expressed in salivary gland tumors and is at higher levels in ACA and MEC.

Tubular variant of basal cell adenoma shares immunophenotypical features with normal intercalated ducts and is closely related to intercalated duct lesions of salivary gland

AIMS

The morphological criteria for identification of intercalated duct lesions (IDLs) of salivary glands have been defined recently. It has been hypothesised that IDL could be a precursor of basal cell adenoma (BCA). BCAs show a variety of histological patterns, and the tubular variant is the one that presents the strongest resemblance with IDLs. The aim of this study was to analyse the morphological and immunohistochemical profiles of IDLs and BCAs classified into tubular and non-tubular subtypes, to determine whether or not IDL and tubular BCA represent distinct entities.

METHODS AND RESULTS

Eight IDLs, nine tubular BCAs and 19 non-tubular BCAs were studied. All tubular BCAs contained IDL-like areas, which represented 20-70% of the tumour. In non-tubular BCA, IDL-like areas were occasional and small (<5%). One patient presented IDLs, tubular BCAs and IDL/tubular BCA combined lesions. Luminal ductal cells of IDLs and tubular BCAs exhibited positivity for CK7, lysozyme, S100 and DOG1. In the non-tubular BCA group, few luminal cells exhibited such an immunoprofile; they were mainly CK14-positive. Basal/myoepithelial cells of IDLs, tubular BCAs and non-tubular BCAs were positive for CK14, calponin, α-SMA and p63; they were more numerous in BCA lesions.

CONCLUSIONS

IDL, tubular BCA and non-tubular BCA form a continuum of lesions in which IDLs are related closely to tubular BCA. In both, the immunoprofile of luminal and myoepithelial cells recapitulates the normal intercalated duct. The difference between the adenoma-like subset of IDLs and tubular BCA rests mainly on the larger numbers of myoepithelial cells in the latter. Our findings indicate that at least some BCAs can arise via IDLs.

Pitfalls in the biopsy diagnosis of intraoral minor salivary gland neoplasms: diagnostic considerations and recommended approach

Among the more common types of intraoral minor salivary gland neoplasms are pleomorphic adenoma, basal cell adenoma, polymorphous low-grade adenocarcinoma, and adenoid cystic carcinoma. These minor salivary gland neoplasms share similar morphologic features and to a large extent immunohistochemical findings. Differentiation between these benign and malignant neoplasms is often predicated on the presence or absence of invasion. As such, in the presence of limited tissue sampling that typifies the initial testing modalities, including fine needle aspiration biopsy and/or incisional biopsy, it often is not possible to differentiate a benign from malignant minor salivary gland neoplasm. The diagnostic difficulties arise from the absence in needle or incisional biopsy of the tumor's periphery to determine whether infiltrative growth is or is not present. In this manuscript we discuss limitations and considerations associated with evaluation of incisional biopsies of intraoral minor salivary gland tumors. We offer a diagnostic approach to evaluating these biopsies, and suggest diagnostic terminology for biopsy specimens in which distinction between benignancy and malignancy is not feasible. The pathologist's approach to this distinction is critical, as treatment of benign neoplasms is generally conservative, whereas malignant lesions may warrant more aggressive management.

Canalicular adenoma immunoprofile: a case report

OBJECTIVES

To report a case of canalicular adenoma (CA) and discuss the use of immunohistochemistry to better address the diagnosis given some unusual characteristics in this patient.

BACKGROUND

CA is an uncommon benign neoplasm that can develop in minor salivary gland duct tissues throughout the oral cavity. At histology, it shares several features with other salivary tumors. Immunohistochemistry can be useful in the differential diagnosis.

MATERIALS AND METHODS

The clinical presentation consisted in a nodule on the left upper lip of an 85-year-old man. The patient's main complaint was upper denture instability secondary to soft tissue changes. The nodule was excised under local anesthesia and underwent histological and immunohistochemical examination to rule out any malignancy.

RESULTS

Histological findings, cytokeratin positivity and the absence of any reactivity to specific markers of myoepithelial differentiation confirmed the epithelial nature of the lesion.

CONCLUSION

The histological diagnosis of benign salivary tumors such as CA can be confirmed by immunohistochemistry.

Canalicular adenoma--search for the cell of origin: ultrastructural and immunohistochemical analysis of 7 cases and review of the literature

Canalicular adenoma (CA) is a rare, benign epithelial neoplasm of the salivary glands. Historically considered to be a variant of basal cell adenoma, this "monomorphic" adenoma has a distinct clinical, morphologic, and immunohistochemical profile. The putative cell of origin remains a topic of debate. A combination of morphology, immunohistochemistry, and ultrastructural analyses have been employed to determine histogenesis, but the interpretations of these studies have implicated multiple different cell types along the salivary gland duct as the cell of origin. The authors sought to further characterize CA using electron microscopy, immunohistochemistry, and special and immuno-stains on 7 cases. Their morphologic, immunohistochemical, and ultrastructural findings support a cell of origin demonstrating features of both the intercalated duct cells and the striated duct luminal epithelial cells.

P63 expression in papillary cystadenoma and mucoepidermoid carcinoma of minor salivary glands

OBJECTIVE

The aim of this study was to investigate the expression of p63 protein in mucoepidermoid carcinoma and papillary cystadenoma of the salivary glands, and to evaluate the usefulness of this protein in distinguishing these tumors.

STUDY DESIGN

Immunoexpression of p63 protein was studied and quantified in 9 formalin-fixed paraffin-embedded mucous retention cysts, 4 papillary cystadenomas, and 19 low-grade and 9 high-grade mucoepidermoid carcinomas.

RESULTS

All cases were positive for p63 immunoexpression; however, it was observed that p63 labeling in mucous retention cysts and papillary cystadenomas was limited to the basal layers of the cystic spaces, whereas in low-grade mucoepidermoid carcinomas, positive nuclear staining was also found diffusely in the suprabasal layers. Mucoepidermoid carcinoma presented increased immunoexpression of p63 compared with the other groups.

CONCLUSIONS

P63 immunohistochemical expression pattern can be helpful in distinguishing low-grade mucoepidermoid carcinoma from papillary cystadenoma of the salivary glands.

Asymptomatic nodules of the upper lip: report of a canalicular adenoma with immunoprofile presentation

Canalicular adenoma is an uncommon benign tumour that generally arises in the minor salivary glands of individuals over 60 years old. This study illustrates a case of canalicular adenoma in a 70-year-old female, presenting as two distinct asymptomatic nodules in the upper lip. Immunohistochemistry analysis was performed. Clinical features, management, histology and immunoprofile from this case and from the literature are discussed.

The Molecular Pathology of Salivary Gland Tumors with Translocations

Presented here are the salivary gland tumors now recognized to have significant and highly prevalent translocations. These include both common and uncommon malignancies: mucoepidermoid carcinoma, adenoid cystic carcinoma, mammary analog secretory carcinoma, and clear cell carcinoma. These mutations have potential diagnostic applications, particularly in difficult and challenging variant morphologies are unusually challenging differential diagnoses. Practical applications of the molecular pathology of these tumors is discussed. The mutational assessment may also prove to have therapeutic importance, as targeted therapies may be generated for these tumors in the future.

An unusual cribriform variant of salivary basal cell tumours: a clinicopathological study of 22 cases

AIMS

To clarify the clinicopathological characteristics of salivary basal cell tumours exhibiting cribriform architecture, and to discuss the differential diagnosis of these tumours with regard to adenoid cystic carcinoma (AdCC).

METHODS AND RESULTS

Eighteen basal cell adenomas (BCAs) and four basal cell adenocarcinomas (BcACs) with at least a 10% area of cribriform morphology were collected, and the histological and immunohistochemical features were evaluated. The majority of tumours showed the typical histological patterns of basal cell tumours, in addition to cribriform architecture. In some areas, the periphery of cribriform nests had a palisade arrangement. Focal capsular infiltration, but not invasion of surrounding normal tissue, was detected in 14 of 18 BCAs. The capsules were absent or incomplete and mainly accompanied by focal invasion in BcACs. Cystic degeneration was observed in 12 of 22 tumours. The Ki67 labelling index of basal cell tumours was significantly lower than that of cribriform AdCCs (P = 0.001). All patients had a good outcome after a follow-up of 15-96 months.

CONCLUSIONS

The cribriform variant shares most of the clinicopathological features of conventional basal cell tumours. Admixtures of cribriform and trabecular or tubulo-trabecular subtypes, peripheral palisading, cystic changes, non-invasive or low-grade invasive growth patterns and a low Ki67 labelling index may be useful for distinguishing basal cell tumours with a cribriform architecture from AdCCs.

Polymorphous low-grade adenocarcinoma: a case report

We present a case of de novo polymorphous low-grade adenocarcinoma (PLGA) arising in a minor salivary gland with a relatively large radiographic extent compared with that of most of the PLGAs reported. This paper describes the radiographic extent of the lesion and the findings of CT imaging.

Rare Malignant and Benign Salivary Gland Epithelial Tumors

Although at least 24 distinct histologic salivary gland carcinomas exist, many of them are rare, comprising only 1% to 2% of all salivary gland tumors. These include epithelial-myoepithelial carcinoma, (hyalinizing) clear cell carcinoma, basal cell adenocarcinoma, cystadenocarcinoma, low-grade salivary duct carcinoma (low-grade cribriform cystadenocarcinoma), oncocytic carcinoma, and adenocarcinoma not otherwise specified. Few tumors (clear cell carcinoma and basal cell adenocarcinoma) have unique molecular correlates. Benign tumors, although histologically less diverse, are far more common, with pleomorphic adenoma and Warthin tumor the most common salivary gland tumors. Many benign tumors have malignant counterparts for which histologic distinction can pose diagnostic challenge.

Development and characterization of xenograft model systems for adenoid cystic carcinoma

Adenoid cystic carcinoma (ACC) is one of the most common malignancies to arise in human salivary glands, and it also arises in the glandular tissue of other organ systems. To address the paucity of experimental model systems for this tumor type, we have undertaken a program of transplanting tissue samples of human ACC into immunodeficient nu/nu mice to create xenograft model systems. In 17 of 23 attempts (74%), xenograft tumors were successfully grown. In all cases, the histologic appearance of the donating tumor was recapitulated in the subsequent xenograft. Characterization of a subset of xenograft models by immunohistochemical biomarkers and by RNA transcript microarray analysis showed good fidelity in the recapitulation of gene expression patterns in the xenograft tumors compared with the human donor tumors. As ACC is known to frequently contain a t(6;9) translocation that fuses the MYB and NFIB genes, fluorescence in situ hybridization (FISH) of 12 ACC xenograft models was performed that assayed MYB locus break-apart and MYB-NFIB locus fusion. Of 12 xenograft models, 11 (92%) revealed MYB locus rearrangement and 10 (83%) showed evidence of fusion of the MYB and NFIB loci. The two related xenograft models (derived from primary and metastatic tumors, respectively, of the same human subject) were karyotyped, showing a t(1;6) translocation, suggesting MYB translocation to a novel fusion partner gene. Overall, our results indicate that ACC is amenable to xenografting and that ACC xenograft models recapitulate the molecular and morphologic characteristics of human tumors, suggesting utility as valid experimental and preclinical model systems for this disease.

Current concepts on dedifferentiation/high-grade transformation in salivary gland tumors

The concept of dedifferentiation had previously been used in salivary gland carcinomas. Recently, the term “high-grade transformation” was introduced for adenoid cystic carcinoma, acinic cell carcinoma, epithelial-myoepithelial carcinoma, and polymorphous low-grade adenocarcinoma and may better reflect this phenomenon, although transformation into moderately differentiated adenocarcinoma (i.e., not “high grade”) has also been described. Among the immunohistochemical markers, Ki-67 seems to be the only one that can help distinguish between the conventional and transformed components; however, the combination of morphological criteria is still sovereign. The overexpression of p53 was observed in the transformed component in all tumor types studied, despite few cases having been demonstrated to carry mutations or deletions in TP53 gene. Genetic studies in salivary gland tumors with dedifferentiation/high-grade transformation are rare and deserve further investigation. This paper aims at providing an overview on the recent concepts in histopathological classification of salivary gland tumors, complemented by immunohistochemical and genetic findings.

Expression and regulation of the ΔN and TAp63 isoforms in salivary gland tumorigenesis clinical and experimental findings

The TP63 gene, a TP53 homologue, encodes for two main isoforms by different promoters: one retains (TA) and the other lacks (ΔN) the transactivation domain. p63 plays a critical role in the maintenance of basal and myoepithelial cells in ectodermally derived tissues and is implicated in tumorigenesis of several neoplastic entities. However, the biological and regulatory roles of these isoforms in salivary gland tumorigenesis remain unknown. Our results show a reciprocal expression between TA and ΔN isoforms in both benign and malignant salivary tumors. The most dominantly expressed were the ΔN isoforms, whereas the TA isoforms showed generally low levels of expression, except in a few tumors. High ΔNp63 expression characterized tumors with aggressive behavior, whereas tumors with high TAp63 expression were significantly smaller and less aggressive. In salivary gland cells, high expression of ΔNp63 led to enhanced cell migration and invasion and suppression of cell senescence independent of TAp63 and/or TP53 gene status. We conclude the following: i) overexpression of ΔNp63 contributes to salivary tumorigenesis, ii) ΔNp63 plays a dominant negative effect on the TA isoform in the modulation of cell migration and invasion, and iii) the ΔN isoform plays an oncogenic role and may represent an attractive target for therapeutic intervention in patients with salivary carcinomas.

Spontaneous Basal cell carcinoma of the submandibular gland in a rat

At necropsy, a white nodule (about 5 × 3 mm in size) was observed in the right submandibular gland of a 10-week-old female GALAS rat. Histopathologically, oval to spindle-shaped and pale basophilic tumor cells proliferated closely, and formed variably sized foci. The nodule partially spread into or invaded the surrounding normal tissue, and necrotic foci were recognized in the tumor. Immunohistochemically, the nuclei of the tumor cells showed a diffusely positive reaction for p63, and the cytoplasm showed a diffusely positive reaction for cytokeratin and negative reaction for αSMA, vimentin, desmin and S-100. Many tumor cells were positive for PCNA. Ultrastructurally, the tumor cells contained many tonofilaments in the cytoplasm and a few desmosomes at the intercellular portion. Based on these findings, the tumor was diagnosed as a basal cell carcinoma originating from the duct in the rat submandibular gland.

Myoepithelial carcinoma of the parotid gland with bilateral thyroid involvement: A case report and review of the literature

A patient was admitted to hospital with enlarged lobes of the thyroid gland with bilateral cervical lymph node involvement, and surgical excision followed. Histological examination of this specimen revealed a lesion that showed myoepithelial cell differentiation. Primary thyroid and skin appendage tumors were excluded based on clinical examination, conventional histology and immunohistochemistry. A tumor of the right parotid surgically treated in June 2008, approximately 2 years previously, was originally classified as a basal cell adenocarcinoma with focal invasion, but was re-examined. Using immunohistochemistry, the parotid tumor was re-classified as a myoepithelial carcinoma. The thyroid tumor proved to be metastasis from a primary parotid tumor, which was not found in the updated review of the literature. The literature is reviewed, including current knowledge on the histological and immunohistochemical features of myoepithelial carcinoma, with limited data on treatment suggestions.

Prognostic value of quantitative p63 immunostaining in adenoid cystic carcinoma of salivary gland assessed by computerized image analysis

BACKGROUND

In a long-term retrospective immunohistochemical study of adenoid cystic carcinoma (ACC) of salivary gland, we investigated the relation of p63 immunodetection to prognosis. Although it is generally agreed that the solid pattern is the most aggressive pattern of growth, ACCs with predominantly cribriform or tubular patterns have an unpredictable clinical course, with a relatively favorable 5-year survival but a low 20-year survival.

METHODS

Formalin-fixed paraffin sections from 35 cases of ACC showing a predominantly better differentiated histopathology, ie, cribriform or tubular patterns of growth, were immunostained for p63. Automated image analysis was used to quantify p63 positivity, using a modification of a previously developed algorithm.

RESULTS

Patients alive for more than 10 years had a lower extent of p63 expression than those who died of disease. Kaplan-Meier analysis revealed that separation of patients with morbidity and mortality from those alive with no evidence of disease, could be achieved at a cutoff of 35% p63 positivity (P = .0031, log-rank test). Multivariate analysis using the Cox proportional hazard model revealed p63 and tumor stage to be independent predictors of survival (P = .012 and P = .0003, respectively).

CONCLUSIONS

To our knowledge, the present study is the first to report prognostic significance of p63 in salivary gland ACC and the first report of a robust and well-studied immunohistochemical stain performable on routinely fixed and processed tissue with prognostic utility.

Intercalated duct lesions of salivary gland: a morphologic spectrum from hyperplasia to adenoma

Intercalated duct lesions (IDLs) are rare, poorly understood and not well-studied lesions that have been associated with a small number of epithelial-myoepithelial carcinomas (EMC) and basal cell adenomas. To examine the nature of IDLs and their association with salivary gland tumors, we reviewed 34 lesions in 32 patients. The IDLs were stained with CK7, estrogen receptors (ER), progesterone receptors, lysozyme, S100, calponin, and CK14. The patients ranged in age from 19 to 80 years (mean 53.8) with a 1.7:1 female predominance. The majorities of IDLs were parotid lesions (82%), were small and nodular (average size 3.1 mm) and showed 3 architectural patterns: hyperplasia (20), adenoma (9), and hybrid forms (5). In 59% of cases, IDLs were seen in conjunction with another salivary gland tumor, most commonly basal cell adenoma (8 cases), followed by EMC (3 cases). One case showed a combination of intercalated duct hyperplasia and basal cell adenoma. The IDLs stained diffusely with CK7 (100%) and S100 (73%) and focally for ER (91%) and lysozyme (100%). Calponin and CK14 highlighted a thin myoepithelial cell layer around all ducts (100%). Normal intercalated ducts were also consistently positive for CK7 and lysozyme, and focally for ER, but were S100 negative. In summary, IDLs have a variety of patterns ranging from hyperplasia to adenoma with hybrid lesions and share morphologic and immunophenotypic features with normal intercalated ducts. There is an association with basal cell adenomas and EMC, which lends credence to their role as a putative precursor lesion.

Synchronous bilateral epithelial-myoepithelial carcinoma of the parotid gland: case report and review of the literature

Synchronous bilateral malignancy in the parotid glands is extremely rare. The English literature reveals nine case reports. The most common synchronous bilateral malignancies are acinic cell carcinoma. Epithelial-myoepithelial carcinoma is an uncommon neoplasm comprising 1% of all salivary gland tumours. In this case report, we describe, to our best of knowledge, the first case of a patient with a synchronous bilateral epithelial-myoepithelial carcinoma of the parotid gland. The clinical histopathological and immunohistochemical peculiarities are elucidated. Imaging studies like ultrasonography are mandatory for both parotid glands and upper necks in the clinical presence of a unilateral parotid gland tumour.

Hierarchical cluster analysis of myoepithelial/basal cell markers in adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma

Distinguishing adenoid cystic carcinoma from polymorphous low-grade adenocarcinoma of the salivary glands is important for their management. We studied the expression of several myoepithelial and basal/stem cell markers (smooth muscle actin, calponin, smooth muscle myosin heavy chain, metallothionein, maspin, and p63) by immunohistochemistry in 23 adenoid cystic carcinoma and 24 polymorphous low-grade adenocarcinoma, to identify the most useful marker or combination of markers that may help their diagnoses. The results were analyzed using hierarchical cluster analysis and chi(2) test for trend. We noted diffuse expression of smooth muscle actin in 20 adenoid cystic carcinoma vs one polymorphous low-grade adenocarcinoma (P<0.0001), calponin in 15 adenoid cystic carcinoma vs one polymorphous low-grade adenocarcinoma (P<0.0001), smooth muscle myosin heavy chain in 15 adenoid cystic carcinoma vs one polymorphous low-grade adenocarcinoma (P=0.001), metallothionein in 22 adenoid cystic carcinoma vs eight polymorphous low-grade adenocarcinoma (P<0.001), maspin in 22 adenoid cystic carcinoma vs 14 polymorphous low-grade adenocarcinoma, and p63 in 21 adenoid cystic carcinoma vs 14 polymorphous low-grade adenocarcinoma. Hierarchical clustering of smooth muscle actin, calponin, smooth muscle myosin heavy chain, and metallothionein was virtually identical (kappa< or =0.0035), suggesting no significant advantage to their use in combination than individually. Diffuse smooth muscle actin expression showed the highest accuracy (91.5%) and positive predictive value (95.2%) for adenoid cystic carcinoma. Thus, diffuse expression of smooth muscle actin, calponin, smooth muscle myosin heavy chain, and metallothionein was highly predictive of adenoid cystic carcinoma, whereas maspin and p63 were frequently expressed in both tumors. In differentiating adenoid cystic carcinoma from polymorphous low-grade adenocarcinoma, smooth muscle actin as a single ancillary test in support of the histological findings, appears to be as efficient as multiple immunohistochemical tests.