Epithelial membrane antigen and DOG1 expression in minor salivary gland tumours.

Epithelial membrane antigen (EMA) and DOG1 are used as marker of epithelial cells, particularly the luminal cells, of salivary gland tumours. The aim of this study was to compare the EMA and DOG1 expression in tumours of minor salivary glands. Cases of pleomorphic adenoma (PA), basal cell adenoma (BCA), canalicular adenoma (CA), adenoid cystic carcinoma (ACC), polymorphous adenocarcinoma (PAC), mucoepidermoid carcinoma (MEC) and epithelial-myoepithelial carcinoma (EMC) were submitted to immunohistochemistry for EMA and DOG1. In PA and BCA, EMA and DOG1 were observed in luminal cells, while in CA the tumour cells were negative for both proteins. The EMA and DOG1 pattern expression detected in EMC was similar to that one observed in benign tumours. In ACC, both myoepithelial e epithelial expressed EMA and DOG-1. PAC tumour cells were only positive for DOG1, whereas MEC were only positive for EMA. In conclusion, EMA and DOG1 expression in benign salivary gland tumours was similar to normal salivary gland tissue and can be used as good marker of tumoral cells derived from intercalated ducts or its progenitor cells, while in malignant salivary gland tumours EMA expression is, however, better used as an indicator of aggressive behavior than a marker of luminal cells.

[Adenoid cystic carcinoma cells produce exosomes that promote tumor cell proliferation].

OBJECTIVE: To observe the effect of exosomes released by adenoid cystic carcinoma (ACC) cell line SACC-83 on the proliferation of ACC cells. METHODS: Exosomes were isolated from SACC-83 cell culture supernatants using total exosome isolation reagents. The whole-mount exosomes were characterized using transmission electron microscope and Western blotting. The exosomes were labeled with green fluorescent dye PKH67 and co-cultured with SACC-83 cells for 48 h, followed by staining with Alexa Fluor 594 phalloidin and DAPI to observe exosome uptake by the cells using laser scanning confocal microscopy (LSCM). The cell proliferation was assessed using MTT assay and wound healing assay, and the expressions of ERK and P-ERK in the co-cultured SACC-83 cells were detected using Western blotting. RESULTS: The exosomes isolated from SACC-83 cells showed a size range of 30-100 nm and expressed the exosomal markers CD9, CD63 and TSG101. LSCM showed exosome uptake by SACC-83 cells, which exhibited accelerated proliferation and significantly enhanced P-ERK expression (P < 0.05) without significant changes in ERK expression. CONCLUSIONS: SACC-83 cells produce exosomes that promote the tumor cell proliferation and enhances the cellular expression of P-ERK, suggesting a potential role of MAPK/ERK pathway activation in exosome-mediated acceleration of ACC cell proliferation.

Mucoepidermoid carcinoma of the posterior-lateral border of tongue: a rare presentation.

Mucoepidermoid carcinoma (MEC) is the most common malignant tumour of the major and minor salivary glands. Minor salivary glands are scattered in different areas of the oral cavity such as palate, retromolar area, floor of the mouth, buccal mucosa, lips and tongue, but so far, only a few lingual MEC cases have been documented in the literature and most of the studies have shown a predilection for base and dorsum of the tongue. We report a rare case of MEC involving the posterior-lateral border of the tongue.

Ultrastructural Characterization of Mammary Analogue Secretory Carcinoma of the Salivary Glands: A Distinct Entity from Acinic Cell Carcinoma?

Mammary analogue secretory carcinoma (MASC) of the salivary glands is a recently described neoplasm of the salivary glands with a characteristic morphology complemented by a specific cytogenetic translocation and gene rearrangements. Although immunophenotypic and cytogenetic differences allow for a more reliable distinction, ultrastructural features can also provide important information about the relationship between MASC, classic acinic cell carcinoma (AciCC), and AciCC intercalated duct cell-predominant variant. Following approval from the hospital's institutional review board, 7 cases of MASC, 8 cases of classic AciCC, and 4 cases of AciCC intercalated duct cell-predominant variant were retrieved from the pathology files of Massachusetts General Hospital from 2012 to 2015. Electron microscopy was performed using formalin-fixed, paraffin-embedded tissue. Ultrastructural features of all 19 neoplasms of the salivary glands were recorded. The predominant cell-types observed in MASC are those with intercalated/striated duct cell differentiation. These features include prominent invaginations of the cell surface studded with microvilli, and some intra- and intercellular lumina also with a microvillous surface. Classic AciCC dominant cell-type recapitulates acinar cell differentiation. These cells contain large intracytoplasmic zymogen-like granules. AciCC intercalated duct cell-predominant variant showed both cell populations in various proportions with the intercalated/striated duct cell type usually being the dominant one. MASC presents with distinctive ultrastructural features that allows its proper differentiation from classic AciCC. However, significant ultrastructural features overlaps between both AciCC intercalated duct cells-predominant and classic AciCC and MASC. These findings indicate a very close proximity between these tumors.

Combined DOG1 and Mammaglobin Immunohistochemistry Is Comparable to ETV6-breakapart Analysis for Differentiating Between Papillary Cystic Variants of Acinic Cell Carcinoma and Mammary Analogue Secretory Carcinoma.

BACKGROUND: We investigated the reliability of combined DOG1 and mammaglobin immunohistochemistry compared with ETV6 fluorescence in situ hybridization (FISH) in the assessment of salivary tumors previously diagnosed as acinic cell carcinoma (ACC). Ultrastructural features of cases reclassified as mammary analogue secretory carcinoma (MASC) were assessed by transmission electron microscopy (TEM). METHODS: Immunohistochemical (IHC) reactivity to DOG1 and mammaglobin was validated against FISH targeting the ETV6 gene in all 14 cases. RESULTS: Three cases with papillary cystic histomorphology previously diagnosed as ACC were revised to MASC. TEM features of the ETV6 rearrangement-positive MASC cases showed large numbers of secretory granules with extrusion into the intercellular spaces, well-developed endoplasmic reticulum, lipid-laden vacuoles, well-formed microvilli, and large lining cystic spaces. CONCLUSIONS: Combined DOG1 and mammaglobin immunohistochemistry is comparable to ETV6 -breakapart analysis for differentiating between papillary cystic variants of ACC and MASC.

Primary ductal adenocarcinoma of the lacrimal gland, associated with abundant intracytoplasmic lumens containing some eosinophilic hyaline globules: cytological, histological and ultrastructural findings.

A primary ductal adenocarcinoma (PDA) of the lacrimal gland is a rare distinct subtype of an epithelial tumor arising in the lacrimal gland. PDA is the counterpart of salivary duct carcinoma (SDC) resembling an invasive ductal carcinoma (IDC) of the breast. In our case, PDA revealed histopathological and immunohistochemical results corresponding to SDC. Interestingly, the tumor cells showed intracytoplasmic vacuoles containing dense eosinophilic hyaline globules at light microscopy. Ultrastructurally, the tumor cells exhibited microvilli-lined intracytoplasmic lumen containing homogenous electron-dense secretory products. A previous study demonstrated that numerous intracytoplasmic lumens of tumor cells are favored breast malignant tumor, similar to the histopathology of PDA, rather than benign lesion. This characteristic finding may be meaningful to diagnose high grade epithelial tumors including PDA.

A perspective of comparative salivary and breast pathology. Part I: microstructural aspects, adaptations and cellular events.

This is the first part of a review comparing the pathology of salivary and mammary glands. Here, less obvious similarities and differences in functional histology and their influences on pathology are examined with emphasis on myoepithelial cells, stromal components, analogues of mucosa-associated lymphoid tissue, steroid receptors, and intraparenchymal cells of monocytic lineage. Particular cell phenotypes (oncocytic, apocrine, neuroendocrine and clear) are critically evaluated and responses to atrophy, infarction and fine-needle aspiration biopsy procedures are highlighted together with aspects of metaplasia, regeneration, ageing and microcalcification. Areas of controversy or uncertainty which may benefit from further investigations are also discussed.

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.

Preoperative assessment of salivary gland neoplasms with fine needle aspiration cytology and echography: a retrospective analysis of 357 cases.

Fine-needle aspiration cytology (FNAC) is a minimally invasive procedure usually well tolerated, easy to perform, quick, cheap and easy to repeat in case of doubts or non-diagnostic results. Echography is also a fast, cheap and non-invasive tool; however, the role of FNAC and echography in the diagnosis of salivary gland pathology is not universally recognised. Three hundred and fifty-seven patients with a cytological diagnosis at FNAC, and 247 of these who were also studied with echography, were enrolled for this retrospective study. The final histopathological diagnoses, obtained after surgery, were then compared to the preoperative FNAC diagnoses and echographic findings. From the analysis of our data, the overall FNAC specificity resulted 93 percent, sensitivity 83 percent, and diagnostic accuracy 92 percent. Echography sensibility was 57.1 percent specificity 98.2 percent, while positive and negative predictive value were respectively 80 percent and 94.8 percent. While echography can be useful in order to provide a better characterization of salivary gland lesions, FNAC can then be considered a safe diagnostic tool with reliable sensitivity and specificity for the assessment of salivary gland pathology and thus for selecting patients and indicating the best surgical treatment.

Establishment and characterization of METON myoepithelioma cell line derived from human palatal myoepithelioma: apical reference to the diverse differentiation potential.

Myoepithelioma is an extremely rare condition that accounts for 1-1.5 % of salivary gland tumors. It was formerly regarded as a subtype of pleomorphic adenoma, in which myoepithelial structural components predominated, but was listed as a separate disease entity in the 1991 World Health Organization classification (Seifert in Histological typing of salivary gland tumours. Springer, Berlin, 1991). Its histology is highly varied and recurrence is frequent (El-Naggar et al. in J Larygol Otol 103:1192-1197, 1989), with cases of malignant transformation having been reported (Seifert in Histological typing of salivary gland tumours. Springer, Berlin, 1991; Barnes et al. in Pathology and Genetics of head and neck tumours. IARC Press, Lyon, 2005), making this a difficult tumor to control in many cases. This is thought to be due to the multiple differentiation potential of myoepithelial cells, but the details are unknown. There have been a number of reports of the establishment of cell lines (Shirasuna et al. Cancer. 45:297-305, 1980; Jaeger et al. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 84:663-667, 1997), but numerous points remain unclear. We established a myoepithelial cell line designated METON, and investigated its characteristics. METON consists of cells with two different morphologies: spindle-shaped cells and epithelial-like cells. Then. we also used single-cell cloning method to establish various subclones (epithelial-like, spindle-like, and mixed epithelial-like/spindle-like cell lines). Among these, pluripotency markers were expressed by the mixed epithelial-like/spindle-like cell lines. The newly established cell line expressing these pluripotency markers will be extremely useful for elucidating the diverse histologies of salivary gland tumors.

Identificación de colágeno I y III con picrosirius red/ polarización en el estroma de tumores salivales / Identification of type I and III collagen by picrosirius red/polarization of tumoral salivary stroma

El estroma juega un rol importante en los procesos tumorales de invasión y metástasis. Las fibras de colágeno tipo I son el principal componente estructural del estroma en distintos tumores. Sin embargo, hay muy pocos estudios en los tumores de glándulas salivales. Basándonos en estos antecedentes el objetivo de la presente comunicación fue estudiar las características del colágeno con Picrosirius red/polarización en tumores benignos y malignos de glándulas salivales para evaluar su posible rol en los mecanismos de progresión tumoral. Cortes histológicos de adenoma pleomórfico, carcinoma adenoide quístico y carcinoma epitelial mioepitelial se colorearon con H/E y Picrosirius red y se examinaron con microscopio de polarización. La birrefringencia del colágeno con Picrosirius/polarización resultó diferente en el estroma de los tumores malignos (carcinoma adenoide quístico y carcinoma epitelial mioepitelial), con predominio de colágeno I, en comparación con el tumor benigno (adenoma pleomórfico), con predominio de colágeno III. El diferente perfil de coloración en las fibras colágenas producidas en el estroma de los tumores analizados podría relacionarse con diferentes mecanismos de expansión tumoral, los que fueron poco estudiados en los tumores de glándulas salivales. Más estudios son necesarios para obtener resultados más concluyentes que contribuyan al diagnóstico, pronóstico y tratamiento.

The stroma plays an important rol in tumoral invasion and metastasis. Type I collagen is the main structural component of the stroma in several tumors. However, there are few studies on salivary gland tumors. Based on this background the objective of the present communication was to study collagen characteristics with picrosirius red/polarization on malignant and benign tumors of salivary glands to evaluate its posible rol in the tumoral progression mechanism. Histological sections of pleomorphic adenoma, adenoid cystic carcinoma and epithelial/myoepithelial carcinoma were stained with H/E and picrosirius red and were studied with polarization microscope. Collagen birefringence with Picrosirius/polarization was different in the malignant tumor stroma (adenoid cystic carcinoma and epithelialmyoepithelial carcinoma), with predominance of type I collagen, compared with a benign tumor (pleomorphic adenoma), with predominance of type III collagen. The different staining profile in collagen fibers produced in the benign and malignant stroma tumors analized could be related with different tumoral expansion mechanism, which were scarce studied on the salivary glands tumors. More studies are needed to obtain more conclusive results to contribute to diagnosis, prognosis and treatment.

Primary oncocytic carcinoma of the salivary glands: a clinicopathologic and immunohistochemical study of 12 cases.

Oncocytic carcinoma (OC) of salivary gland origin is an extremely rare proliferation of malignant oncocytes with adenocarcinomatous architectural phenotypes, including infiltrative qualities. To help clarify the clinicopathologic and prognostic features of this tumor group, herein, we report 12 OC cases arising from the salivary glands, together with follow-up data and immunohistochemical observations. There were 10 males and 2 females with an age range of 41 to 86 years (median age: 61.3 years). Most occurred in the parotid gland (10/12) with one in the palate and one in the retromolar gland. The tumors were unencapsulated and often invaded into the nearby gland, lymphatic tissues and nerves. The neoplastic cells had eosinophilic granular cytoplasm and round vesicular nuclei with prominent red nucleoli. Ultrastructural study, PTAH, and immunohistochemistry staining confirmed the presence of numerous mitochondria in the cytoplasm of oncocytes. Cellular atypia and pleomorphism varied in the current series. Double nuclei and mitoses were observed in some cases, while one case that showed mild cellular pleomorphism but had local invasion following local recurrence was also identified as an OC. Of the 11 cases with follow-up information, 7 cases had local recurrence. Regional or distant metastases were found in 6 and 4 cases, respectively. Five-year disease-specific survivals were 54.9%. In summary, OC of salivary gland origin is a high-grade tumor, often with local recurrence, regional or distant metastasis, diagnosis of which based on a combination of clinical and histopathological features. Immunohistochemistry for mitochondria is considered as a practical and helpful adjuvant diagnosis. Complete surgical excision is the treatment of choice while the role of radiotherapy or chemotherapy is controversial, and careful follow-up is necessary.

Correlation between mucoepidermoid carcinoma grade and AgNOR count.

Mucoepidermoid carcinoma (MEC) is a malignant glandular epithelial neoplasm having an unpredictable behavior and a tendency to recur. Numerous parameters have been assessed to predict the outcome of this lesion, but have been deemed inadequate, with the exception of tumor stage and grade. In the present study, we attempted to correlate the proliferative activity of MEC with its histopathological grade, using argyrophillic nuclear organizer region (AgNOR) count. Thirty cases of MEC were included in the study. All the slides were stained using hematoxylin and eosin and silver nitrate techniques. Counting was performed at a magnification of x1,000 with an oil-immersion lens. Positive correlations were seen between AgNOR count and MEC grade (P < 0.05), with AgNOR count increasing in proportion with tumor grade. The AgNOR count in various grades of MEC indicates a relative progression in the proliferative activity of this tumor. This index is positively correlated with tumor grade, although there are some exceptions. The utility of AgNOR count in predicting the prognosis of MEC can be considered of importance; however, further assessment, such as survival studies, is necessary.

Clear cell carcinoma: review of its histomorphogenesis and classification as a squamous cell lesion.

In current classification schemes, clear cell carcinoma-including both the hyalinized and nonhyalinized variety--is now an accepted subtype of malignant salivary gland tumors. Despite this, the underlying cellular differentiation process leading to the typical histomorphology of this neoplasm remains unclear. This review summarizes and illustrates the histologic, ultrastructural, and immunohistochemical evidence for the underlying squamous cell nature of clear cell carcinoma. Squamous cell differentiation is not an uncommon feature of nonneoplastic and neoplastic lesions of the salivary glands. Clear cell carcinoma needs to be added to this list as a unique but specific variety of clear cell squamous carcinoma.

Ultrastructural immunolocalization of a cartilage-specific proteoglycan, aggrecan, in salivary pleomorphic adenomas.

A pleomorphic adenoma (PA) is the most common epithelial tumor in the salivary glands, but it frequently shows a mesenchyme-like histology, including the presence of myxoid and chondroid areas. Cartilage-specific matrix proteins are deposited in PA. Aggrecan is a major component of cartilage-specific proteoglycans. The present study examined the ultrastructure of the stromal areas in ten salivary PA specimens and investigated the distribution of aggrecan by immunoelectron microscopy. Aggrecan was deposited in the myxoid and chondroid stroma of PA. Ultrastructural observations revealed many proteoglycan cores and fibrils in the myxoid stroma and some spindle-shaped neoplastic myoepithelial cells with vacuoles and actin filaments in the myxoid areas. By immunoelectron microscopy, positivity for aggrecan was observed in the vacuoles of neoplastic myoepithelial cells, which coexisted with the viscous materials, and it was also frequently seen in electron-dense crystals in the myxoid stroma. These findings suggest that neoplastic myoepithelial cells produce aggrecan and release it from vacuoles, and aggrecan is then deposited in the myxoid stroma. Aggrecan deposition is therefore considered to play an important role in the formation of the mesenchyme-like stroma, especially the myxoid stroma.

Collagenous crystalloids in myoepithelial carcinoma: report of a case and review of the literature.

Since the first report of "tyrosine crystals" in a parotid mixed tumor by Bullock in 1953, authors have described several types of crystalloids in association with mixed tumor and related neoplastic and nonneoplastic entities. The principal classes of these include tyrosine-rich crystalloids, collagenous crystalloids, and one class variously referred to as tyrosine-rich crystals, nontyrosine crystalloids, and amylase crystalloids. We report a myoepithelial carcinoma of minor salivary gland origin containing numerous collagenous crystalloids. To our knowledge, this represents the first report of collagenous crystalloids in a case of myoepithelial carcinoma. In addition, we searched our institution's files for cases of pure myoepithelial tumors. No crystalloids of any form were identified in 27 myoepitheliomas and 15 myoepithelial carcinomas. We review the literature on salivary-related crystalloids, and we propose the term oncocyte/cyst-associated crystalloids to encompass the aforementioned third class of crystalloid. Given distinct morphologic and histochemical properties and given relatively limited disease associations, we conclude that in the appropriate clinical context, the identification of these crystalloids can be diagnostically useful.

Fine needle aspiration cytology of basal cell adenoma of the salivary gland.

OBJECTIVE: To formulate cytologic features for differential diagnosis of basal cell adenoma (BCA). STUDY DESIGN: The usefulness of 5 items for a cytologically definitive diagnosis of BCA was examined. The 5 items in 8 BCA and 22 non-BCA cases (adenoid cystic carcinoma [ADCC], basal cell adenocarcinoma, myoepithelioma, pleomorphic adenoma and polymorphous low-grade adenocarcinoma) that displayed mimicking cytology were examined cytologically. RESULTS: The useful items were < 5.1 microm in mean of epithelial nuclear short diameter; mild atypia on definitive diagnosis; stromal cell cluster combining smooth margin surrounding the epithelial cell cluster or containing the epithelial cell cluster; epithelial clusters surrounded by or adhered to a thick, hyalinized smooth margin without stromal cluster; and closely fastened, tight clusters with denser cytoplasm than ADCC, but an indistinct border, with oval nuclei and no hyaline cells. CONCLUSION: Five items are useful criteria for BCA.

Distinguishing adenoid cystic carcinoma from cylindromatous adenomas in salivary fine-needle aspirates: the cytologic clues and their ultrastructural basis.

The utilization of fine-needle aspiration (FNA) biopsy in salivary tumors is hindered by the reluctance of many cytopathologists to report adenoid cystic carcinoma (ACC) because its cylindromatous stroma is observed occasionally in pleomorphic adenoma (PA) and basal cell adenoma (BA), and a diagnosis of ACC results in radical surgery. The aim of this study is to identify dependable features to distinguish the look-alike entities and illustrate their ultrastructural base. We compared 20 cases of ACC to 15 cases of cylindromatous PA and 9 cases of BA. All were direct smears stained with Diff-Quik, hematoxylin and eosin, Papanicolaou, or Ultrafast Papanicolaou (UFP) stain. In addition to the presence of cylindromatous pattern, the amount of cytoplasm in the neoplastic cells and nuclear features were compared. Tissue was dissected from paraffin blocks and processed for electron microscopy in selected cases. The difference in nuclear features can be distinguished in UFP-stained smears and electron microscopy. The nuclei of ACCs were heterochromatic with coarse chromatin and irregular nucleoli, whereas the nuclei of PAs were euchromatic with fine chromatin and small compact nucleoli. The nuclei of BAs were hyperchromatic but finely textured. The cytoplasm of PAs was detectable with every stain at 40x objective, but the cytoplasm of BAs required UFP stain and 100x objective to be detected. The cytoplasm of majority of neoplastic cells of ACCs are invisible, because the thin rim of cytoplasm measured <1 microm ultrastructurally, well beyond the resolution of a light microscope. Rare cohesive fragment of epithelial cells in ACC have scanty blue cytoplasm in UFP stain and can be recognized as ductal cells. In conclusion, in our analysis of salivary tumors with a cylindromatous pattern, the seemingly naked nuclei of neoplastic cells with their coarse nuclear chromatin and irregular nucleoli, as revealed by the UFP stain, reliably distinguished ACC from cylindromatous adenomas.

The ultrastructural aspects of neoplastic myoepithelial cell in pleomorphic adenomas of salivary glands.

The purpose of this study has been to establish the major ultrastructural aspects of the myoepithelial cell and the myoepithelial-like cells proliferated in the pleomorphic adenomas of salivary glands. Thus, twelve benign pleomorphic adenomas of salivary glands have been studied by electron-microscopy transmission techniques. Our analysis has proved the proliferation of two major cellular populations, one of ductal type and one of myoepithelial type, which tried to reproduce the tubulo-acinar cytoarchitecture from the normal salivary glands. We have also noticed the key role of the so-called 'modified' myoepithelial cells from the periphery of the proliferating epithelial units in the genesis of the myxoid and chondromyxoid tumoral stromal areas. All these ultrastructural aspects have explained the great histological diversity of these salivary gland neoplasms as well as the key role of the myoepithelial cell in its histogenesis.