Immunofluorescence study of secretory epithelial markers in pleomorphic adenomas

Steroid hormone receptors in parotid gland cystadenolymphoma (Warthin's tumour)

The aetiopathogenesis of cystadenolymphoma is mostly unknown. Cystadenolymphomas have a significantly higher incidence in the male than the female population. This might be as a result of endocrine dependency in this kind of tumour. The purpose of the present study was to determine the sex hormone receptor status in cystadenolymphoma. Tissue samples of cystadenolymphoma, pleomorphic adenoma and normal samples of the parotid gland were examined immunohistochemically for oestrogen and progesterone receptors. Progesterone-positive cells could be found in the salivary duct system of normal glands and in the epithelial components of cystadenolymphomas. There was no evidence for the presence of oestrogen receptor in any sample studied. The evidence of progesterone receptors in cystadenolymphoma may implicate a potential role of endocrine factors in the development of this tumour.

Characterization of a novel cell line from pleomorphic adenoma of the parotid gland with myoepithelial phenotype and producing interleukin-6 as an autocrine growth factor

A cell line was obtained from a primary culture of a pleomorphic adenoma of the parotid gland in a 24-year-old woman. The cells of the line (PA 16/23) grew spontaneously in minimal culture conditions and showed stable morphologic characteristics over 30 passages. PA 16/23 cells had immunophenotypic and ultrastructural features similar to those of transformed myoepithelial cells, which are regarded as the precursors of pleomorphic adenomas. Furthermore, these cells have been demonstrated immunocytochemically to contain interleukin-6 (IL-6) on light and electron microscopic examination. IL-6 also has been found by enzyme-linked immunosorbent assay in the culture supernatant and has been proven to be capable of stimulating growth of the PA 16/23 cells.

Altered expression of ABO (H) carbohydrate antigens is seen in pleomorphic adenomas

Cell surface carbohydrate antigens show changes in relation to differentiation, maturation and malignant transformation. The expression of type 2 chain ABH carbohydrate structures of the ABO histo-blood group system was investigated in 28 pleomorphic adenomas (PA) and normal parotid glands in order to study possible changes in the glycosylation pattern. The distribution of carbohydrate structures was investigated by immunohistological stainings of formalin-fixed paraffin-embedded material using monoclonal antibodies (MAbs) with well-defined specificity. A strong interindividual variation was found in the normal tissue as well as in the tumors. In normal tissue, acinus and duct cells all expressed elongated carbohydrate structures. The yoepithelial cells did not stain with any of the MAbs investigated. In the PAs, staining was seen in the ductular structures and myoepithelial cells. In contrast to normal tissue, the tumors expressed the short precursor molecule sialylated N-acetyllactosamine. Furthermore, the PAs showed loss of H and A antigens, and a reduced expression of Le(y) compared to normal tissue. The ductular structures as well as the modified myoepithelial cells expressed binary N-acetyllactosamine, which in the normal tissue could only be found in the striated and excretory ducts. Thus our study has shown that aberrant glycosylation is not only a feature of malignant neoplasms but also occurs in pleomorphic adenomas.

An immunohistochemical study of the distribution of lysozyme, lactoferrin, alpha 1-antitrypsin and alpha 1-antichymotrypsin in salivary adenoid cystic carcinoma

The immunohistochemical expression of lysozyme (Ly), lactoferrin (La), alpha 1-antitrypsin (alpha 1-AT), and alpha 1-antichymotrypsin (alpha 1-Ach) was described, and their distributions were compared to each other in 28 cases of adenoid cystic carcinoma (ACC) of the salivary glands. ACC materials were obtained from the parotid gland (7), the submandibular gland (4), the sublingual gland (8), and minor oral salivary glands (9). Histopathologically, ACC was classified into cribriform (14), tubular (3), and basaloid or solid patterns (11). Positive staining for Ly was found in 1 case of solid ACC in the sublingual gland; La was found in 4 cases (2 cribriform, 1 tubular, 1 basaloid) in the sublinguals (3) and parotid glands (1); alpha 1-AT was found in 6 cases and alpha 1-Ach in 17 cases. The immunohistochemical localization of Ly and La was usually confined to luminal tumor cells of tubulo-ductal structures, irrespective of the pathologic types. Positive staining for alpha 1-AT and alpha 1-Ach appeared in tumor cells of cribriform, tubular and solid ACC. Tumor cells with positive La staining coincided with a positive reaction to alpha 1-AT and alpha 1-Ach, and tumor cells with alpha 1-AT positive deposition were also positive for alpha 1-Ach. The contents of pseudocysts in the cribriform pattern showed a positive reaction to La, alpha 1-AT, and alpha 1-Ach. Of the 28 cases of ACC, positive expressions for Ly, La, alpha 1-AT and alpha 1-Ach were found with a high frequency of alpha 1-Ach staining (17 in 28 cases were positive). In sublingual ACC (8), 7 cases were positive for immunohistochemical reactions. Co-expression or simultaneous expression for Ly, La, alpha 1-AT, and alpha 1-Ach in ACC suggest that tumor cells are protected from proteolysis or degradation.

Pleomorphic adenoma of the breast: a clinicopathologic and immunohistochemical study of 10 cases

Pleomorphic adenomas of the breast (PAB) are uncommon tumors. We studied the clinicopathologic features of 10 cases of PAB, seven of which were assessed immunohistochemically. Nine patients were women, with a median age at diagnosis of 65 years. Eight patients presented with a palpable mass; two had a nipple discharge. Nine of the tumors were periareolar. The latter epidemiologic findings, coupled with histologic observations, appeared to indicate a preferential origin for PAB within large intramammary ducts. These neoplasms histologically resemble their analogues in salivary glands. Moreover, a gradual histologic transition between different morphologic areas in PAB, especially between mesenchymal and epithelial regions, supported the contention that the neoplasm arises from a single cell type capable of divergent differentiation and thus should not be considered a "mixed" tumor. This contention was further substantiated by immunohistochemical findings, in which three intermediate filaments (cytokeratin, vimentin, and glial fibrillary acidic protein) and muscle-specific actin were expressed conjointly in tumor cells with a variety of morphologic appearances. In addition, cells differentiating along mesenchymal lines by conventional microscopy were found to express epithelial membrane antigen or gross cystic disease fluid protein-15 in five cases. The benign nature of PAB was supported by a lack of metastases in this series during a median follow-up period of 4.9 years. However, one lesion recurred locally. Regarding therapy, we believe that PAB can be excised successfully with only a narrow circumferential margin of uninvolved breast.

Immunohistochemical study of four histologic types of parotid gland pleomorphic adenoma

The immunohistochemical detection of lysozyme, lactoferrin, a1-antichymotrypsin and a1-antitrypsin was used to investigate the marker expression and histogenesis of each one of four histologic types of 20 parotid gland pleomorphic adenomas. Moreover, 10 adult and 20 neonate parotid glands were studied. The immunohistochemical analysis revealed that tumor types 1 and 2 are nearly identical immunohistochemically while types 3 and 4 differ from one another, as well as from types 1 and 2. The markers used failed to suggest that the tumor arises from epithelial cells of any specific anatomic part of the parotid gland.

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.

Two-colour immunofluorescence marker study of pleomorphic adenomas

Extensive use of two-colour immunofluorescence staining for various cell markers in pleomorphic adenoma, revealed three consistent phenotypic features: (1) keratin polypeptide No. 14, which was virtually restricted to myoepithelial cells (MEC) in normal salivary glands, appeared in a large fraction of the tumour cells, suggesting that the principal neoplastic element is derived from MEC or their immediate precursors; (2) a complex co-expression pattern of various cell markers was found, with extensive concurrence of keratin and vimentin in strands of MEC-like and myxoid tumour cells, probably reflecting different degrees of tumour cell differentiation; and (3) two phenotypically distinctive dendritic cell populations were identified, one consisting of keratin positive tumour cells and the other of HLA-DR positive but keratin negative stromal cells. The significance of these findings with regard to the histogenesis and complex morphology of pleomorphic adenoma is discussed.

Immunohistochemical characterization of epithelial cells in human lacrimal glands. II. Inflammatory and neoplastic lesions of lacrimal glands

The distribution of cytokeratins (CK), actin, lactoferrin (Lf), lysozyme (Ly), vimentin and S-100 protein was immunohistochemically investigated in paraffin-embedded specimens of five inflammatory and five neoplastic lesions of lacrimal glands (LGs). Atrophic acini in dacryoadenitis reacted with antibodies (ABs) KL1 and Pkk1 (CK 7, 8, 17, 18) in a manner similar to ducts. Apart from myoepithelial cells and some luminal-duct cells, the remaining epithelia in dacryoadenitis were negative with AB 34 beta E12 (CK 5). The number of AB HHF35 (actin)-positive myoepithelial cells was not altered in dacryoadenitis. Epithelia in dacryoadenitis reacted weakly but consistently with Lf while revealing weak and inconsistent staining for Ly. Vimentin was negative in epithelial cells in dacryoadenitis except in one case. S-100 protein was detected only in epithelia of inflammatory major LGs. Epimyoepithelial islands in lymphoepithelial proliferation reacted variably for CKs, Lf, Ly and vimentin and remained negative for actin and S-100. In pleomorphic adenomas, neoplastic cells showing duct-like differentiation (luminal) reacted consistently with CK 7, 8, 17, 18 and S-100 protein and inconsistently with CK 5, Lf and Ly but remained negative for actin and vimentin. Other neoplastic cells (ovoid/peripheral cells) stained consistently for CK 5, vimentin and S-100 protein and focally for CK 7, 8, 17, 18, actin, Lf and Ly. Spindle-form neoplastic cells found in the stroma exhibited vimentin and S-100 protein and, less frequently, actin. Determination of these antigens in pleomorphic LG adenomas may help to evaluate their prognosis.

Immunohistochemical demonstration of lysozyme and lactoferrin in salivary pleomorphic adenomas

Immunohistochemical identification of lysozyme and lactoferrin was made in salivary pleomorphic adenomas (147 cases) and the staining patterns were evaluated with respect to the histological features and histogenesis. In normal salivary glands, the intercalated duct cells gave positive staining for lysozyme in major glands, and serous acinar cells, demilune cells, and interlobular duct cells were positive in minor glands. Lactoferrin staining was irregularly positive in serous cells and ductal epithelium. In pleomorphic adenomas, the reaction for lysozyme was positive in 14% (21/147) of the cases, and was confined to luminal cells of tubulo-ductal structures. Lactoferrin in pleomorphic adenomas was distributed in luminal tumor cells (51%; 75/147), in outer tumor cells (3%; 4/147), and in both luminal and outer tumor cells (5%; 7/147) in tubulo-ductal structures; it was also detected in plasmacytoid myoepithelial cells (5%, 8/147). However, modified myoepithelial cells and other types of neoplastic myoepithelial participants were negative for lactoferrin staining. The occurrence of both lysozyme and lactoferrin in salivary pleomorphic adenomas suggests their participation in the local defense mechanism in the tumor.

Ultrastructural morphology of secretory granules in pleomorphic adenoma of human parotid and submandibular salivary glands

Secretory granules were found in some of the cells lining the lumina of typical epithelial structures in pleomorphic adenomas. They were small, of varied electron density, and were mostly unipartite, sometimes bipartite and occasionally tripartite. They most closely resembled secretory granules of intercalary ductal cells of normal salivary glands.

Immunohistochemical demonstration of steroid C-21 hydroxylase in normal and neoplastic salivary glands

The presence of steroid C-21 hydroxylase in normal and neoplastic salivary glands was investigated immunohistochemically with the use of antibody against cytochrome P-450 specific for steroid 21-hydroxylation (P-450C21). In normal salivary glands, P-450C21 was exclusively present in the excretory duct system (intercalating, striated and large excretory ducts), and not observed in acini. In salivary gland tumors, P-450C21 was observed in most epithelial cells of duct origin within pleomorphic adenomas including cells of amorphous groups scattered in myxoid areas, and in adenolymphoma. Some mucous cells in mucoepidermoid tumor also were positive for this enzyme. These findings in the normal and neoplastic salivary gland suggest that the expression of P-450C21 is closely related to ductal differentiation.

Pleomorphic adenoma with a predominantly myoepithelial proliferation of the vagina

A case of pleomorphic adenoma of the vagina in a 44-year-old woman was described. The tumor was a submucosal mass measuring 3.5 X 2 X 2 cm and located in the left lateral wall 1.5 cm inside the introitus. Histologically, it was predominantly composed of sheets and strands of spindle-shaped or polygonal cells focally dispersed in the myxoid tissue to form pseudomicrocysts. Ultrastructure demonstrated the basal lamina, desmosomes, variable amounts of filaments of both intermediate and microfilament, and occasionally microvilli in these tumor cells indicating that dominant cells were myoepithelial in nature. With immunohistochemical studies, keratin and cytokeratin were positive, whereas, S-100 protein, glial fibrillary acidic protein, vimentin, secretory component, and lysozyme were negative. The previously published cases were reviewed and compared with the present case.

Immunohistochemical localization of amylase in sialoadenitis and salivary gland tumors

Immunohistochemical demonstration of alpha-amylase has been made in sialoadenitis-involved tissue and salivary gland tumors, as well as in normal salivary glands. Immunoreactive alpha-amylase with trypsin pretreatment was confined to irregularly staining serous acinar cells in the parotid and submandibular glands, and to demilunes in sublingual glands. In obstructive adenitis, staining was irregular from high to negative in acini in early or intermediate stages. Dilated ductal segments contained cells positive for alpha-amylase in the early stage following obstruction. Pleomorphic adenomas were usually negative for alpha-amylase but in rare cases tumor epithelia stained variably positive; i.e., staining occurred throughout the cytoplasm or at the periphery or apical part of the tumor cells. Luminal cavities of tubular and duct-like structures contained alpha-amylase-positive material. Epithelia in Warthin's tumor were also negative in general; however, scattered single or grouped tumor cells containing alpha-amylase were found. Mucoepidermoid tumors were also negative, though slightly positive cells were found intermingled among the negative squamous and mucous tumor cells. Cystic lesions in mucoepidermoid tumor were sometimes positive in the wall cells together with material secreted into the lumen.

Immunohistochemical localization of alpha 1-antitrypsin and alpha 1-antichymotrypsin in salivary pleomorphic adenomas

Immunohistochemical identification of alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-ACh) in pleomorphic adenomas of salivary glands is reported in order to compare their distribution profiles with those of lysozyme and lactoferrin, already described elsewhere. Normal salivary glands indicated positive alpha 1-AT staining in ductal segments and had no alpha 1-ACh in any glandular cell. Pleomorphic adenomas displayed moderate positivity to alpha 1-AT staining in duct-like, tubular and glandular epithelia which was particularly intense in luminal cells. The limited number of tumour cells which showed duct-like structures with a single cellular layer arrangement, displayed the highest staining to alpha 1-ACh. Strongly alpha 1-AT positive tumour cells located on the inner side of luminal cavities were also markedly positive to alpha 1-ACh. Spindle shaped tumour cells existed outside tubular and ductal structures and were negative to alpha 1-AT and alpha 1-ACh. Distribution of alpha 1-AT in salivary glands was similar to that of lysozyme as is usual in ductal segments or their transformed cells, and occurrence of alpha 1-ACh localization rather resembled that of lactoferrin, with occurrence in acinar compartments and changed epithelia within acini. The biological role of a specific immunohistochemical distribution of alpha 1-AT and alpha 1-ACh in pleomorphic adenomas may be associated with a self regulating mechanism which inhibits degradation by tissue proteinases.