Multiple expression of keratins, vimentin, and S-100 protein in pleomorphic salivary adenomas

Study of minor salivary gland mucoepidermoid carcinoma differentiation based on immunohistochemical expression of cytokeratins, vimentin and muscle-specific actin

The expression of cytokeratins (CKs) 7,8,10,13,14,18,19, vimentin and muscle-specific actin (MSA) was investigated in 17 mucoepidermoid carcinomas (MEC) by the streptavidin-biotin technique. The results revealed that CKs 7, 8 and 18 were positive for intermediate, luminal columnar and mucous cells. For epidermoid cells, the expression was heterogeneous and discrete. The reaction with CK19 was similar to that seen for the above CKs, except for the fact that mucous cells were negative. CK 14 was preferentially expressed in the intermediate cells localised in basal, parabasal and epidermoid cells. CK13 was localised in intermediate, epidermoid and luminal columnar cells. In stratified epithelium, CK13 was expressed in intermediate cells and negative in basal cells. These findings were more expressive in cystic areas of the tumours. CK10 was negative for all the cases studied. MSA was positive only in stromal elements, and only two cases of CME were heterogeneously positive for vimentin. The result obtained showed that the immunoprofile of MEC, for the studied antigens, is similar to that exhibited by the excretory duct of normal salivary glands.

Expression of cytokeratins in Warthin's tumour (adenolymphoma) of parotid glands: specific detection of individual cytokeratin types by monoclonal antibodies

This study evaluated the distribution of cytokeratins detected by monoclonal antibodies directed against individual keratin proteins in normal human salivary glands and epithelial tumour cells of Warthin's tumour arising in parotid glands to determine a more precise mapping of their cellular distribution. The normal salivary ducts showed the presence of cytokeratin 7, 8, 18 and 19 in the intercalated, striated and excretory ducts, the primary keratins of stratified and simple epithelia with a profile very similar to the non-cornified epithelium of the oral mucosa. The basally located cells of salivary gland ducts other than myoepithelial cells were reactive for keratins 7 and 19 suggesting a close similarity in profile of keratin in the basal cells of the oral epithelium. In Warthin's tumour, keratins 7, 8, 18 and 19 were consistently detected in the epithelial cells of the tumour, a profile with a tendency to mimic the same in normal ductal epithelium. The distribution, however, was diverse and a heterogeneity was observed in the basal and luminal cells of Warthin's tumour which differed even in different areas of the same tumour specimen.

Expression of different keratins in salivary gland tumours

Twenty-four salivary gland tumours (six pleomorphic adenomas, two myoepitheliomas, five basal cell adenomas, six adenoid cystic carcinomas and five polymorphous low grade adenocarcinomas) were investigated by an immunocytochemical technique using monoclonal antibodies against cytokeratins (CKs) 7, 8, 10, 13, 14, 18 and 19. The luminal cells of ductal structures of the tumours reacted with all the CKs studied except for CK 13 and CK 10 and sometimes CK 14, showing an immunoprofile comparable to that of the intercalated segment of a normal salivary gland. The outer cells of the ducts rarely stained with CK 14, confirming that full differentiation of the myoepithelial cells is seldom achieved in tumours. Considerations were made regarding the intriguing expression of CK 14, the heterogeneous expression of CKs in the modified myoepithelial cells and the immunoprofile of the polymorphous low-grade adenocarcinoma.

Pulmonary myxoid leiomyosarcoma

A primary myxoid leiomyosarcoma arising from the peripheral bronchus of the right middle lobe was removed from a 20 year old man and examined by immunohistochemistry and electron microscopy. The tumor was well circumscribed, yellow-whitish focal polypoid growth into the bronchial lumen and consisted of spindle cells with abundant myxoid substance in the stroma. Intrapulmonary metastasis, invasion to the bronchial wall and a few mitotic figures were found. Immunohistochemically, several, but not all, tumor cells were positive against anti-vimentin, anti-S-100 protein, anti-myosin and anti-muscle specific actin. Ultrastructurally, tumor cells had thin filaments with dense bodies, pinocytic vesicles and discontinuous basal lamina. These findings indicate a myoxoid variant of leiomyosarcoma arising from mesenchyme in the peribronchial area.

Thomsen-Friedenreich (T) antigen as marker of myoepithelial and basal cells in the parotid gland, pleomorphic adenomas and adenoid cystic carcinomas. An immunohistological comparison between T and sialosyl-T antigens, alpha-smooth muscle actin and cytokeratin 14

Controversy centres on the role and identification of myoepithelial (MEC) and basal cells in salivary gland tumours, and recent studies suggest that both basal cells and myoepithelial cells participate in the formation of salivary gland tumours. We have correlated the expression of different well-known markers of normal MEC/basal cells (i.e. alpha-smooth muscle actin and cytokeratin 14) with T (Thomsen-Friedenreich) antigen and its sialylated derivative: sialosyl-T antigen,) in 17 normal parotid glands and in two tumour types with MEC participation (i.e pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC)) using immunohistology with well-defined monoclonal antibodies (MAbs). Paraffin-embedded/fresh frozen tissue sections were studied from 33/17 patients with PA and 15/7 patients with ACC. In normal parotid tissue coexpression of alpha-smooth muscle actin, cytokeratin 14, T and sialosyl-T antigens was found in all MEC and in some of the basal cells lining striated ducts. The remaining basal cells exclusively expressed cytokeratin 14, T and sialosyl-T antigens. In the tumours, cells believed to be modified myoepithelial cells showed two different staining patterns: 1) Coexpression of alpha-smooth muscle actin, cytokeratin 14, T and sialosyl-T antigens, and 2) Coexpression of cytokeratin 14, T and sialosyl-T antigens, but no alpha-smooth muscle actin. The epithelial ductular structures in the tumours showed aberrant expression of cytokeratin 14, T and sialosyl-T antigens, and cytokeratin 14 was the only marker of cells in solid undifferentiated areas of adenoid cystic carcinomas. Our study supports the view, that modified "myoepithelial" cells in the tumours consist of a mixture of basal cells and myoepithelial cells. None of the investigated structures was in itself an ideal marker in the identification of MEC/basal cells. The cells can be identified by a combination of markers (i.e. cytokeratin 14, alpha-smooth-muscle actin, T and sialosyl-T antigens).

S100 protein in oral biology and pathology

The demonstration of S100 protein is used extensively for both research and diagnostic purposes in oral biology and pathology. This article reviews the structure and putative function of S100, technicalities of S100 immunohistochemistry, the cells of the oral and perioral tissues which express S100 and the possible significance of S100 expression in disease.

Immunohistochemical evaluation of bone morphogenetic protein (BMP) in mixed tumor of skin

Immunohistochemical reaction of bone morphogenetic protein (BMP) was assessed in 19 cases of skin mixed tumor and 5 cases of skin appendage tumors by using monoclonal antibody raised against BMP. All cases of skin mixed tumor showed positive staining for BMP in modified myoepithelial cells located at the periphery of tubulo-ductal or solid structures, and in plasmacytoid or tumor cells in hyalinous structures. Chondroidally changed cells also showed a strong BMP immunoreactivity. Tumors originating from sweat glands were devoid of BMP immunoreactivity. It is concluded that BMP is synthesized and produced in modified or transformed myoepithelial cells in skin mixed tumor and participates in the process of chondroid changes in the tumor.

Histogenesis and possible mechanism of chondroid changes in mixed tumour of the skin: immunohistochemical evaluation of bone morphogenetic protein, glycosaminoglycans, keratin, vimentin and neuronal markers

The distribution of immunoreactivity of bone morphogenetic protein (BMP), the glycosaminoglycans chondroitin 4-sulphate (C4SPG), chondroitin 6-sulphate (C6SPG), dermatan sulphate (DSPG) and keratan sulphate proteoglycans (KSPG), cytokeratin (K8.12), vimentin, glial fibrillary acidic protein (GFAP), actin, desmin, S-100 protein and neuron-specific enolase (NSE) in mixed tumour of the skin was investigated using immunohistochemical methods using monoclonal (MoAb) and polyclonal antibodies (PoAb). A strong BMP immunoreactivity was found characteristically in outer tumour cells of tubuloductal structures and modified myoepithelial cells. Modified myoepithelial cells and chondroidally changed cells showed positive immunoreactivity for C4SPG, C6SPG and DSPG; and KSPG was more pronounced in the modified myoepithelial cells. Vimentin, S-100 protein, GFAP and NSE, but not actin and desmin, were distribute in the outer tumour cells and modified myoepithelial cells in chondroidally changed tissue. Two factors show that chondrogenesis in mixed tumour of the skin is associated with the modified myoepithelial cells through the activity of BMP and biosynthesis of glycosaminoglycans as matrix substance. First, outer or basal tumour cells in mixed tumour of the skin is characterized by the presence of positive immunoreactivity for BMP, KSPG, vimentin, cytokeratin K8.12, S-100 protein, GFAP and NSE, and second, there is a matrix of chondroidally changed tissue containing the reaction products of C4SPG, C6SPG, DSPF and KSPG.

Immunocytochemical localization of bone morphogenetic proteins (BMPs) in salivary gland pleomorphic adenoma

The localization of bone morphogenetic protein (BMP)-1, -2, -3 and transforming growth factor (TGF)-beta in normal salivary gland and pleomorphic adenoma of the salivary gland has been examined immunocytochemically. Tumor cells with BMP immunostaining in pleomorphic adenoma were associated with some solid cellular and tubuloglandular patterns, and with stellate cells in the myxoid area. In addition, in the chondroid area of three pleomorphic adenomas, chondrocyte-like cells were positive for BMPs. It is speculated that BMPs secreted by the tumor cells play a role in the formation of the chondroid component in pleomorphic adenoma by inducing some tumor cells, probably neoplastic myoepithelial cells, to differentiate to chondrocytes by metaplastic change. No tumor cells specifically immunostained with TGF-beta were found. TGF-beta was positive in fibrous and hyalinized stroma. In the submandibular gland, only anti-BMP-1 antibody specifically reacted to apical portions of degenerated serous acinar cells.

Chronotoxicological effect of methyl mercury in rat submandibular gland. Immunohistochemical changes of r-EGF, S-100 protein and keratin

The effect of toxicity of methyl mercury was investigated in the submandibular gland (SMG) of adult male rats subjected to 12 h light dark cycle (6 a.m. to 6 p.m. light/resting phase; 6 a.m. to 6 p.m. dark/active phase). Two groups of rats received a defined dose of methyl mercury hydroxide at seven different time points during the active (dark) and resting (light) phase over a 24 h period. After 10 d, the rats were killed at 9 a.m. and 9 p.m. in the resting and active phase, respectively. The immunohistochemical distribution pattern of epidermal growth factor (r-EGF), S-100 protein and K8.12 keratin were studied in granular convoluted tubules (GCT). Those rats which received injections during the active phase (6 p.m. to 6 a.m.), showed stronger reactivity for r-EGF; however, the reactivity for S-100 protein was unchanged. On the contrary, in both groups, GCT cells showed intense staining for K8.12 keratin. It is concluded that the detoxification mechanism of mercury appears to be dependent on the chronobiological oscillation pattern of the GCT and their substructures.

Immunohistochemical detection of S-100, S-100 alpha, S-100 beta proteins, glial fibrillary acidic protein, and neuron specific enolase in the prenatal and adult human salivary glands

Developing human fetal salivary glands of gestational age from 10 to 40 weeks (n = 100) and normal adult glands (n = 10) were examined for immunoreactivity to S-100 protein and its subunits S-100 alpha, S-100 beta, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE). In the early intermediate developmental stage (19-32 weeks) some acinar basal cells showed immunoreactivity to S-100 protein which rapidly disappeared in the late developmental stage (33-40 weeks). Adult salivary glands were negative for S-100 protein. The S-100 alpha subunit was strongly positive in the glandular ducts and acini of both fetal and adult glands. The S-100 beta, although present in some acini and ductal cells during the late intermediate developmental stage, was rarely seen in the adult glands. GFAP and NSE was positive at the developing salivary epithelium in the early developmental stage (15-18 weeks). The above findings indicated that the developing salivary epithelia showed transient appearance of the neuronal phenotype during active cytodifferentiation stage of glandular acini and ducts. Therefore, after evaluation of normal developmental and neoplastic transformation of the salivary glands a suggestion that neuronal differentiation of ductal reserve cells is responsible for the production of modified myoepithelial cells in both normal developmental salivary gland and neoplastic transformation is made.

An immunohistochemical study of bone morphogenetic protein in pleomorphic adenoma of the salivary gland

Bone morphogenetic protein (BMP) is a potent induction factor for new bone formation including heterotopic chondro-ossification in soft tissues. The immunohistochemical reaction for BMP was studied in 23 cases of pleomorphic adenoma of salivary gland by using a monoclonal antibody produced by hybridoma technique. Positive BMP immunoreactivity was seen in 87% of tumours. Immunohistochemical expression of BMP was observed in modified myoepithelial cells (88% cases), luminal tumour cells of tubulo-ductal structures (78% cases) and chondroid cells in hyaline tissue (22% cases). The authors concluded that the simultaneous presence of glycosaminoglycans as matrix substance with BMP-mediated cellular activity of modified myoepithelial cells in the formation of chondroid structures in pleomorphic adenomas of the salivary glands.

Vimentin expression in sweat gland tumours

Immunohistochemical localization of vimentin was studied in 93 cases of sweat gland tumours using a monoclonal anti-vimentin antibody. A strong immunoreactivity of vimentin was observed in modified myoepithelial or neoplastic myoepithelial cells of mixed tumour of the skin, syringoma, and sweat gland adenoma. Tumour cells in outer layers of tubular, ductal, and duct-like structures usually showed positive staining for vimentin, which coincided with modified myoepithelial cells. All tumour cells of clear cell hydroadenoma showed positive vimentin staining. Tumour cells of the luminal border of tubulo-ductal structures of mixed tumours were rarely immunoreactive for vimentin. Positive vimentin staining of tumour cells in the outer zone of tubulo-ductal structures in sweat gland tumours may be related to reactive proliferation of modified myoepithelial cells and simultaneous growth of luminal tumour cells.