Morphological heterogeneity of oral salivary gland carcinomas: a clinicopathologic study of 41 cases with long term follow-up emphasizing the overlapping spectrum of adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma

We analyzed 41 oral salivary gland carcinomas from consecutive 290 salivary gland carcinoma database (14%) with emphasis on the histological spectrum and clinical outcome of adenoid cystic carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA). The cohort included 14 ACCs, 14 mucoepidermoid carcinomas (MECs), 8 PLGAs, 3 adenocarcinomas, not otherwise specified and 2 acinic cell carcinomas. Mean age was 48, 58 and 61 yrs for ACC, MEC and PLGA, respectively. Eight patients (19.5%) died of tumor at a mean interval of 66.5 months. ACC and PLGA showed similar mean age, gender distribution, predominant palatal localization, nodal metastasis, perineural invasion and MIB-1 index. However, ACC tended to show higher tumor stage and residual tumor (R1/R2) more frequently than PLGA, but this was statistically not significant. ACC and PLGA showed overlapping architectural patterns. However, ACCs displayed well organized basal-luminal differentiation, highlighted by CK5/CK7 immunostaining. In contrast, PLGA showed a disorganized histological and immunohistological pattern. C-Kit expression (CD117) was common in ACC, generally mirroring that of CK7 and virtually lacking in PLGA. Kaplan-Meier analysis demonstrated a similar clinical course for ACC and PLGA with 5 years survivals of 87% and 80%, respectively. Fluorescence in situ hybridization (FISH) performed on all 290 salivary carcinomas confirmed the specificity of the translocation t (11; 19) for MEC and its absence in all other carcinomas including ACC and PLGA. Our results emphasize the diversity of oral salivary gland carcinomas and the overlapping clinicopathological features of ACC and PLGA.     

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.     

Pleomorphic adenomas,adenoid cystic carcinomas and adenolymphomas of salivary glands analysed by a monoclonal antibody against myoepithelial/basal cells

Summary Myoepithelial and basal cells were identified by a monoclonal antibody raised against keratin. This antibody (CK B1) which detects myoepithelial cells in normal salivary glands, labels spindle shaped and polygonal cells in pleomorphic adenomas. Most cells in adenoid cystic carcinomas and some basal cells in adenolymphomas were also positive for this antibody. The oncocytic epithelium of adenolymphoma was negative.An inverse reaction was seen with an antibody against cytokeratin 18.The antibody CK B1 seems to be of interest for the detection of myoepithelial/basal cells in salivary glands and salivary gland tumours.Dedicated to Prof. Dr. G. Seifert on the occasion of his 65th birthdaySupported by the Deutsche Forschungsgemeinschaft and by the Hamburger Stiftung zur Förderung der Krebsbekämpfung     

The myoepithelial immunophenotype in 135 benign and malignant salivary gland tumors other than pleomorphic adenoma.

BACKGROUND: We have previously studied the immunoreactivity of 3 novel smooth muscle-specific proteins, alpha-smooth muscle actin, smooth muscle myosin heavy chains, and calponin, to assess myoepithelial differentiation in pleomorphic adenomas. OBJECTIVE: To further expand our knowledge of myoepithelial differentiation in other benign and malignant salivary gland tumors. DESIGN: Formalin-fixed paraffin sections of 135 salivary gland tumors with associated normal glands were stained with monoclonal antibodies using the avidin-biotin complex immunoperoxidase method and enzymatic and microwave heat-induced epitope retrieval. RESULTS: In adenoid cystic carcinomas and epithelial-myoepithelial carcinomas, all 3 markers exclusively highlighted the myoepithelial cell components and the epithelial cells were entirely negative. No immunostaining was detected in canalicular adenomas, oncocytomas, Warthin tumors, acinic cell carcinomas, mucoepidermoid carcinomas, squamous cell carcinomas, and polymorphous low-grade adenocarcinomas. Salivary duct carcinomas and adenocarcinomas, not otherwise specified had a distinctive pattern of uniform periductal staining of reactive myofibroblastic cells, and in salivary duct carcinomas some ducts retained a peripheral immunoreactive myoepithelial cell layer. CONCLUSION: Immunoreactivity for these 3 smooth muscle-specific proteins confirms the known neoplastic myoepithelial component of adenoid cystic carcinomas and epithelial-myoepithelial carcinomas. The consistently positive staining pattern in adenoid cystic carcinomas may be diagnostically useful in discriminating histologically similar but consistently negative polymorphous low-grade adenocarcinomas. Periductal linear staining in adenocarcinoma, not otherwise specified and salivary duct carcinomas is distinctive and appears to represent a tight cuff of myofibroblasts associated with the infiltrating glands.     

Immunophenotypical profiles of salivary gland tumours: a new evidence for their histogenetic origin

The histogenetic origin of salivary gland tumours is not clear. In normal tissues smooth muscle actin (SMA) is expressed in myoepithelial cells, CK14 immunoreactivity is seen in myoepithelial and basal cells and CK10 in keratinized squamous epithelium. In this study, we examine the immunophenotypic properties of salivary gland tumours in order to obtain further insight into their histogenesis. 30 cases of salivary gland tumours (18 pleomorphic adenomas, 8 Warthin's tumours, 2 basal cell adenomas, 2 acinic cell carcinomas) were included in our study. Cytokeratin (CK) 10, CKI4, CKI7, CK18, CK 19, and smooth muscle actin (SMA) immunostains were applied to the sections. Immunoreactivities were detected and the statistical significance was evaluated by chi square test. SMA was not detected in Warthin's tumour (p < 0.0001). CK14 was found in all tumours except acinic cell carcinomas (p < 0.0001). CK10 immunoreactivity was observed in 5 Warthin's tumour. In conclusion, pleomorphic adenomas and basal cells adenomas originate from stem cells. Immunophenotypic profile of Warthin's tumour is suggestive of an embryological remnant origin.     

Myoepithelial cell markers in salivary gland neoplasms

We compared the immunoexpression of 5 myoepithelial cell (MEC) markers (alpha-smooth-muscle actin, calponin, h-caldesmon, vimentin, and S-100-protein) using 16 pleomorphic adenomas (PA), 15 adenoid cystic carcinomas (ACC), and 3 epithelial-myoepithelial carcinomas (EMC) of salivary glands. The alpha-smooth-muscle actin was useful for identification of MECs, especially in cribriform and tubular ACC, followed by EMC. Calponin was similar to alpha-smooth-muscle actin, except for polygonal and plasmacytoid cells of PA and for solid ACC, which showed alpha-smooth-muscle actin negative and calponin positive. H-caldesmon was negative. Vimentin immunostained all MEC types, and was negative in luminal cells. S-100 protein was expressed both in the nuclei and cytoplasm of MECs and luminal cells, especially in PA. The best way to identify MEC is using alpha-smooth-muscle actin or calponin, plus vimentin, since in tumors MECs are hardly ever fully differentiated.     

Unique expression of MUC3, MUC5AC and cytokeratins in salivary gland carcinomas

The differential diagnosis of salivary gland carcinoma is often difficult because of the confusing histopathological features of the different types of salivary gland carcinomas. The expression of MUC3, MUC5AC, MUC6, cytokeratin (CK)7 and CK20 was studied in 20 mucoepidermoid carcinomas (MEC), 20 adenoid cystic carcinomas (AdCC), and 11 acinic cell carcinomas (ACC). All the cases (51/51, 100%) were positive for CK7, but they were not positive for CK20. All the cases (100%) of the MEC were positive for MUC5AC, while all MEC (100%) were negative for MUC3. Only two cases (10%) were positive for MUC6. All cases (100%) of AdCC were negative for MUC3, MUC5AC and MUC6. Eight cases (73%) of ACC were positive for MUC3, but all the cases (100%) were negative for MUC5AC and MUC6. It is concluded that the positive expression of MUC5AC is very unique to MEC, and that the positive expression of MUC3 is very unique to ACC. These findings will be very useful for the differential diagnosis of the salivary gland carcinomas.     

Salivary duct carcinoma in five cats.

Carcinomas of salivary gland ducts are described in five cats. The typical histological pattern was the formation of large cell aggregates resembling dilated ducts, often with central necrosis and a looping pattern. All tumours were labelled with antibody to cytokeratins (CKs) 5, 6, 8, 14, 17 and 19. Labelling of tumour cells with CK14 suggested basal cell differentiation. All tumours stained with Jack bean (Canavalia ensiformis) agglutinin (Con A); this is a feature of normal salivary gland ducts but is seen in other salivary gland tumours. Staining of tumour cells at the luminal surface of ductal structures with wheat germ (Triticum vulgaris) agglutinin (WGA) in the cat tumours was similar to that seen in ducts of normal cat salivary glands but occurs in other cat tumours. Other immunohistochemical staining results were unremarkable. 1999 Harcourt Publishers Ltd.     

Selected topics in salivary gland tumour pathology

The complexity of salivary tumours is largely due to the participation of neoplastic myoepithelial cells which exhibit remarkable phenotypic and secretory abilities. The proportions and morphologic appearances of ductal and myoepithelial cells, type of tumour matrix and relation of tumour cells with extracellular matrix is what defines entities such as mixed tumours, myoepitheliomas, adenoid cystic carcinomas, epithelial/myoepithelial carcinoma, and basal cell adenocarcinoma. Other lesions such as polymorphous low-grade adenocarcinoma, acinic cell carcinoma, and hyalinizing clear cell carcinoma show little or no myoepithelial differentiation. Understanding this so-called morphogenetic concept is quite important in the diagnosis of these tumours. Pathologic grading of salivary gland tumours is generally implied in the diagnosis; however, tumour grade provides significant prognostic information in mucoepidermoid carcinoma, carcinoma ex-pleomorphic adenoma, and adenoid cystic carcinoma.     

Adenoid cystic carcinoma of the ovary

We describe a case of ovarian adenoid cystic carcinoma (ACC) of the left ovary in a 23-year-old woman. The tumor had the typical cribriform pattern of ACC, lacked any component of surface epithelial carcinoma, and showed myoepithelial differentiation. The features of salivary gland-type tumor seen in this case are unusual and different from those of so-called ACC-like carcinomas of the ovary, which only resemble the salivary gland tumor histologically.     

CK7 expression in carcinomas of the Waldeyer's ring area

Primary carcinomas of the Waldeyer's ring area are typically nonkeratinizing squamous cell carcinomas (SCC). Their cervical lymph node metastases are not uncommonly cystic and filled with necrotic tumor cells. Some cysts, however, contain clear fluid. During the investigation of SCC producing "fluid-filled" cystic metastases, we evaluated hematoxylin and eosin (H&E) sections of 90 primary SCC for their site of origin. We analyzed the cytokeratin (CK) profile of primary and metastatic carcinoma with special focus on the expression of CK7, a putative marker for ductal differentiation. CK7 was expressed in submucosal minor salivary gland acini and ducts, but not in the squamous surface epithelium of the Waldeyer's ring. CK7 was expressed in 11 primary SCC (8 base of tongue/3 palatine tonsil). The CK7-positive SCC were deep-seated, arose from large excretory ducts of submucosal minor salivary glands, and showed only insignificant surface involvement. They were characterized by a solid infiltrative growth pattern of basaloid cells with focal ductal differentiation. Salivary ducts adjacent to the carcinoma showed extensive intraductal hyperplasia and metaplasia. All CK7-positive carcinomas produced CK7-positive cystic nodal metastases, most of which contained paucicellular fluid. No solid CK7-positive nodal metastases were identified. In summary, a subset of carcinomas occurring in the Waldeyer's ring area appear to arise from large excretory ducts of submucosal minor salivary glands with only limited surface involvement, express CK7, and produce CK7-positive cystic "fluid-filled" nodal metastases. The histomorphology and immunophenotype suggest that these carcinomas represent basaloid SCC arising from excretory ducts of the submucosal minor salivary glands.     

Basement membrane proteins in salivary gland tumours

Summary Immunohistochemical localization of type IV collagen and laminin in normal salivary glands and in salivary gland tumours of various types was studied using rabbit antisera. In normal salivary glands, type IV collagen and laminin were co-localized in basement membranes surrounding acini, ducts, fat cells and peripheral nerves. In salivary gland tumours, three main patterns of co-expression of these basement membrane proteins were distinguished. Linear basement membrane-like staining was detected in duct-cell-derived benign salivary gland tumours and in acinic cell carcinomas. In invasive lesions, however, these basement membrane proteins were distributed in an irregular, interrupted manner, and in many cases they were completely absent. Both benign and malignant salivary gland tumours which have a prominent myoepithelial cell component display a particular deposition of basement membrane molecules adjacent to the modified myoepithelial cells, and at the margins of extracellular matrix deposits within these tumours.     

Diagnostic role of DOG1 and p63 immunohistochemistry in salivary gland carcinomas

Background: The differential diagnosis of salivary carcinomas is always difficult and challenging. Salivary neoplasms often shows more than one growth pattern and significant morphologic variability may exist within a single tumor and between different tumors. The aim of this study was to examine the role of DOG1 (discovered on gastrointestinal tumor-1) and p63 immunohistochemistry in the diagnosis and differential diagnosis of salivary carcinomas. Methods: we examined the expression of DOG1 and p63 immunohistochemistry in 33 mucoepidermoid carcinomas (MEC), 9 acinic cell carcinomas (ACC), 10 adenoid cystic carcinomas (AdCC) and 4 myoepithelial carcinomas. Results: All ACC showed strong to moderate positivity for DOG1 (P=0.001) and all were totally negative for p63. All MEC expressed strong to moderate positivity for p63 (P=0.001) while only (9.1%) were weak to moderately positive for DOG1. (80%) AdCC were moderately positive for DOG1 in ductal and myoepithelial components and (100%) showed moderate positivity for p63 in myoepithelial cells only (P=0.001). All myoepithelial carcinomas were DOG1 negative, 2 (50%) were weakly positive for p63 while the other 2 were moderately positive (P=0.5). Conclusion: DOG1 is a sensitive marker in the diagnosis of acinic cell carcinoma, p63 is sensitive in the diagnosis of mucoepidermoid carcinoma, the combined use of both markers is helpful and statistically significant in the differential diagnosis of acinic cell carcinoma versus mucoepidermoid carcinoma, both markers can help in the diagnosis of adenoid cystic carcinoma but they have no role in the diagnosis of myoepithelial carcinoma.     

Cytologic diagnosis of adenoid cystic carcinoma of salivary glands.

The cytomorphologic features in fine-needle aspiration (FNA) biopsies from 31 primary and 33 recurrent adenoid cystic carcinomas (ACC) were investigated. The correct FNA diagnosis was established in 24 of 31 primary ACC (77%). The diagnostic clue in aspirates from ACC are large globules of extracellular matrix, partially surrounded by basaloid tumor cells. In FNAs with predominance of basaloid tumor cells, but lacking characteristic globules, all other benign and malignant salivary gland tumors of epithelial-myoepithelial differentiation should be considered in the cytologic diagnosis. Pleomorphic adenoma is most frequently confused with ACC, and therefore, the cytologic findings in FNAs from 50 pleomorphic adenomas were compared with those diagnosed as ACC. Furthermore, rare neoplasms of salivary glands with epithelial-myoepithelial cell differentiation, including basal-cell adenoma and carcinoma, epithelial-myoepithelial carcinoma, and polymorphous low-grade adenocarcinoma, as well as some nonsalivary gland neoplasms presenting an adenoid cystic pattern, must be considered. The cytologic features of these entities are discussed in detail with respect to the cytologic diagnostic criteria of ACC.     

Immunohistochemical investigation of vimentin, neuron-specific enolase, alpha 1-antichymotrypsin and alpha 1-antitrypsin in adenoid cystic carcinoma of the salivary gland

Fifty-four adenoid cystic carcinomas (ACC) arising in major and minor salivary glands as well as in normal salivary glands were studied by immunohistochemistry for the presence of vimentin, neuron-specific enolase (NSE), alpha 1-antichymotrypsin (alpha 1-ACT) and alpha 1-antitrypsin (alpha 1-AT). Five patterns of histological differentiation were found in ACC, and for the cellular components of each, it was possible to establish a special immunohistochemical profile. In ACC, vimentin-positive cells were observed in the outer tubular, cyst-lining and small angular cells. NSE was positive in the myoepithelial cells of normal salivary gland. Neoplastic cells of ACC showed NSE positivity mainly in the small angular cells and partly in the duct luminal cells. alpha 1-ACT was localized in the intercalated duct cells and serous acinar cells of normal salivary gland, and in the duct luminal cells of ACC. alpha 1-AT could not be detected in any of the epithelial cells of normal salivary gland. In ACC, eosinophilic hyaline material in the cribriform spaces was positive for alpha 1-AT, but no positivity was demonstrated in tumor cells. The present study showed that there are at least two populations of tumor cells in ACC: duct luminal cells that express alpha 1-ACT, thus indicating their ductal character, and small angular cells that express vimentin, characteristic of non-luminal cells. Moreover, our results indicate that alpha 1-AT is a useful marker of basement membrane-like material.     

IMMUNOHISTOCHEMICAL STUDY OF OVEREXPRESSION OF FIBROBLAST GROWTH FACTOR-1 (FGF-1), FGF-2, AND FGF RECEPTOR-1 IN HUMAN MALIGNANT SALIVARY GLAND TUMOURS

Fibroblast growth factor-1 (FGF-1) and FGF-2 are broad spectrum mitogens. The expression of FGF-1, FGF-2, and their receptor, FGF receptor-1 (FGFR-1), was examined in malignant salivary gland tumours and normal salivary glands, using immunohistochemical methods. In seven cases of adenoid cystic carcinoma (ACC), both duct-like cells and modified myoepithelial cells were apparently immunopositive for FGF-1, FGF-2, and FGFR-1. In five cases of mucoepidermoid carcinoma (MC), all three types of tumour cells including epidermoid cells, mucous cells, and intermediate cells expressed immunoreactive FGF-1, FGF-2, and FGFR-1. In these malignant salivary gland tumours, increased expression of FGFR-1 correlated with the intensity of both FGF-1 and FGF-2 immunoreactivity. In contrast to malignant salivary gland tumours, eight cases of normal salivary gland showed negative immunostaining for FGF-1, FGF-2, and FGFR-1 while four cases were weakly immunoreactive for FGF and its receptor. These results demonstrate that malignant salivary gland tumours overexpress FGF-1, FGF-2, and FGFR-1 compared with normal salivary glands and suggest that these growth factors may play an important role in facilitating neoplastic progression in human salivary glands.     

Distribution of p63, cytokeratins 5/6 and cytokeratin 14 in 51 normal and 400 neoplastic human tissue samples using TARP-4 multi-tumor tissue microarray

p63, cytokeratin (CK) 5/6 and CK 14 have been employed in diagnostic pathology as markers of basal, squamous and myoepithelial differentiation in several types of human neoplasms; however, there is scant data on the concurrent expression of these markers in large series of human neoplasms. We analyzed the distribution of these three immunohistochemical markers in 51 normal human tissue samples, 350 carcinomas, 25 malignant melanomas (MMs), and 25 glioblastomas using three serial sections of tissue array research program (TARP)-4 multi-tumor tissue microarray. Also, we performed double immunostainings to characterize the differential distribution of p63/CK 5/6 and p63/CK 14 in normal breast, salivary gland and skin. p63, CK 5/6 and CK 14 were expressed in basal cells of the prostate and respiratory epithelia and in breast and bronchial myoepithelial cells. p63 was also expressed in cytotrophoblast cells of human placenta and in scattered cells of lymph node germinal center. CK 5/6 and CK 14 also stained the cytoplasm of basal cells of esophageal stratified squamous epithelium and transitional epithelial cells of the bladder. No mesenchymal, neural, endothelial, smooth muscle or adipose cells were stained by any of the markers. p63, CK 5/6, and CK 14 were respectively expressed in 92.6%, 75.0%, and 52.9% of the squamous cell carcinomas of the lung, 10.2%, 20.0%, and 7.4% of the ductal carcinomas of the breast, 12.9%, 34.4%, and 11.8% of the serous and 25.0%, 0%, and 0% of the endometrioid carcinomas of the ovary. Lung, prostate and colonic adenocarcinomas, as well as MMs and glioblastomas were only rarely decorated by one of the markers. Only matched samples of 16 squamous cell carcinomas and two ductal carcinomas of the breast co-expressed these three markers. In double immunostainings, p63-CK 5/6, as well as p63-CK 14 were co-expressed by basal/myoepithelial cells of the salivary glands and basal cells of the epidermis. Our results demonstrate that p63, CK 5/6 and CK 14 may be used together in immunohistochemical panels to characterize squamous differentiation in poorly differentiated carcinomas or carcinomas of unknown origin.     

Immunohistochemical localization of vitamin B12 R-binder in salivary gland tumors. Implications for cell differentiation

Vitamin B12 R-binder, a specific binding protein for vitamin B12, was studied immunohistochemically in normal and 106 neoplastic salivary gland tissues with a monoclonal antibody against vitamin B12 R-binder (R-binder). In normal salivary glands, R-binder localization was restricted to the ductal systems and to mucous acinar cells; serous acinar cells, myoepithelial cells and stromal connective tissues were consistently negative. Among salivary gland tumors, R-binder was present in 87% of pleomorphic adenomas, 100% of monomorphic adenomas, and 40% of adenoid cystic carcinomas; positivity was observed only on luminal surfaces of small ductular elements, indicating that the components closely related to ductal differentiation were rather small in population. R-binder could be detected both in lacunar and non-lacunar cells within chondroid areas of pleomorphic adenomas, suggesting the possibility that chondroid regions arise from metaplastic changes in ductal epithelial cells. In mucoepidermoid tumors, mucous cells and focal squamous cells exhibited cytoplasmic staining. The staining pattern for R-binder in epithelial components of adenolymphomas showed close similarities to those found in normal large excretory ducts. Two acinic cell tumors and one case each of myoepithelioma and malignant myoepithelioma exhibited negative reactivity for R-binder, showing that these neoplasms are solely composed of tumor cells without the characteristics of ductular differentiation. The immunohistochemical examination of salivary gland tumors, employing a monoclonal anti-R-binder antibody, may have some implications for cellular heterogeneity and differentiation in various tumors.     

Immunohistochemical distribution of human epidermal growth factor in salivary gland tumours

Summary Immunohistochemical identification of human epidermal growth factor (hEGF) was carried out in a total of 152 cases of salivary gland tumours, consisting 107 pleomorphic adenomas and their variants, 13 adenolymphomas and 32 adenoid cystic carcinomas. A high percentage of pleomorphic adenomas revealed markedly positive hEGF staining of the luminal surface cells of tubuloductal structures and of modified or neoplastic myoepithelial cells. Clear cells of the tumour showed various reactivities from very slight to strong. Eosinophilic epithelial cells of adenolymphoma gave a positive reaction for hEGF in all the cases, whereas most adenoid cystic adenoma lacked hEGF staining; however some cases showed positive staining of the tumour cells. The immunohistochemical detection of hEGF in most salivary gland tumours suggests this factor to be a possible new marker of salivary glands tumours, and to have a biological role in tumour proliferation.