Intermediate filaments cytokeratin and vimentin in ovarian sex cord-stromal tumours with correlative studies in adult and fetal ovaries

The expression of the intermediate filaments cytokeratin and vimentin were studied immunohistochemically in a series of ovarian sex cord-stromal tumours (26 adult and juvenile granulosa cell tumours, 11 thecomas, six fibromas, three Sertoli-Leydig cell tumours and 1 sex cord tumour with annular tubules). Contrary to previous reports, granulosa cell tumours expressed cytokeratins as well as vimentin. Thecomas and fibromas expressed vimentin only. In Sertoli-Leydig cell tumours and the sex cord tumour with annular tubules, both cytokeratins and vimentin were detected. Correlative studies in adult ovaries showed that patterns of expression in non-neoplastic granulosa, thecal and stromal cells correspond to their neoplastic counterparts. Investigation of fetal ovaries demonstrated that these patterns of intermediate filament expression exist from relatively early stages of development. Ovarian surface epithelium and rete ovarii, like granulosa cells, co-expressed cytokeratin and vimentin. The demonstration of cytokeratins in granulosa cells and the reported presence of desmosomes and tonofilaments, suggests the epithelial nature of these cells although not clarifying their histogenesis. The presence of both these intermediate filaments in granulosa and Sertoli-Leydig cell tumours as well as in some ovarian carcinomas which may mimic them, limits their value in differential diagnosis between these tumour groups.     

Expression of cytokeratins and vimentin in salivary gland carcinomas as revealed with monoclonal antibodies

Summary The expression and distribution of cytokeratins and vimentin in fifteen malignant salivary neoplasms were examined by immunocytochemical techniques using, five monoclonal antibodies (mAbs) against different epitopes of Cytokeratins (CKs) (mAbs PKK1, PKK2, and PKK3, identifying CKs 8, 18 and 19, CKs 7, 17 and 19, and CK 18, respectively) and Vimentin (mAbs V9 and V24). Antibody PKK1 gave strong reactions in all neoplasms showing the similarity of these tumours to other digestive system adenocarcinomas. Three general staining patterns of the neoplasms were recognized with respect to the reactivity of mAbs PKK2, PKK3, and V9. Mucoepidermoid cancer, salivary duct carcinoma and a clear cell carcinoma had a higher relative content of CKs 7, 17 and 19 than of CK 18. Adenoid cystic carcinoma showed the same CK pattern but in the periphery of the tumour cords vimentin was readily detected. In two acinic cell carcinomas, the relative content of CK 18 was higher than that of CKs 7, 17 and 19. Furthermore vimentin was expressed in the tumour cells. However, one mucoepidermoid carcinoma showed vimentin expression and two acinic cell carcinomas were vimentin negative and more reative for PKK2 than PKK3. Pecularities in CK expression were seen: squamous areas of mucoepidermoid carcinomas were stained by mAb PKK3 although CK 18 is not present in normal squamous epithelia or in squamous cell carcinomas of tongue and skin. In conclusion, the different salivary neoplasms can be distinguished on basis of IFP content. Such a differentiation fits with current theories of histogenesis, i.e. vimentin is seen in tumours presumed to arise from intercalated duct reserve cells, whilst the vimentin negative neoplasms would be expected to arise in excretory duct reserve cells.     

Expression of cytokeratins and vimentin in epithelial cells of normal and pathologic thyroid tissue

Summary The presence of intermediate filament proteins of the cytokeratin and vimentin type was evaluated in normal and pathologically changed thyroid tissue specimens. Using the indirect immunoperoxidase technique with 4 different cytokeratin monoclonal antibodies: RCK114 (broad spectred), K2080 (broad spectred), RGE53 (directed against component 18, present in simple epithelium) and RKSE60 (directed against component 10, associated with keratinization). Co-expression of cytokeratin and vimentin was evaluated with a double immunoenzyme staining technique.The results indicate that normal and transformed cells express cytokeratins of the non-epidermal type. Cytokeratins of the epidermal type are sometimes present in carcinomas. They do not differentiate in tumour type (i.e. papillary, follicular, anaplastic or medullary carcinoma).The co-expression of cytokeratins and vimentin is not restricted to carcinomas: in a small percentage of cases it is also present in normal epithelial cells of the thyroid gland. Moreover, the distribution pattern of cytokeratins and vimentin within the cell is changed in malignant transformed epithelial cells of the gland and seems to be inversely related to the degree of differentiation of these cells. The implications of our findings for the possible use of cytokeratins and vimentin in diagnostic pathology are discussed.     

The distribution pattern of cytokeratin and vimentin immunoreactivity in testicular biopsies of infertile men

Testicular biopsies of infertile patients are often characterized by a mixed atrophy, in which different types of spermatogenic lesions are found in adjacent tubules. In order to evaluate a possible involvement of the state of differentiation of the Sertoli cells, the distribution pattern of cytokeratin and vimentin intermediate filaments within the seminiferous epithelium of 228 biopsy specimens with normal spermatogenesis (n=10), mixed atrophy (n= 206) or Sertoli Cell Only Syndrome (n=12) were investigated by means of immunohistochemical techniques. Sertoli cells were regularly found to show vimentin expression in tubules with normal spermatogenesis as well as in tubules with any kind of spermatogenic impairment including SCO. Cytokeratin expression as a marker showing lack of differentiation was common in Sertoli cells of tubules with arrest of spermatogenesis at the level of spermatogonia, and was occasionally associated with arrest at the level of primary spermatocytes or with SCO. Ultrastructural examination of tubules with spermatogonial arrest revealed Sertoli cells with features of typical fetal or prepubertal Sertoli cells, such as round to ovoid nuclei without indentations, stacks of rough ER and spot desmosomes. These data suggest that spermatogenic arrest at the level of spermatogonia might be due to functional impairment of the associated Sertoli cells, which have maintained or regained an undifferentiated state and are not able to initiate or trigger the process of spermatogonial differentiation.     

Investigating differentiation mechanisms of the constituent cells of sex cord-stromal tumours of the ovary

SOX-9, an essential factor for male sexual development, can be induced by prostaglandin D2 in a Sry-independent mechanism. Recent data suggest that the hedgehog pathway is involved in the differentiation of normal Sertoli and Leydig cells. The purpose of our study was to investigate the mechanisms involved in the differentiation of ovarian sex cord-stromal tumour (SCST) cells. Two Sertoli-Leydig cell tumours and two granulosa cell tumours with a minor Sertoli element were studied using immunohistochemistry on paraffin-embedded tissue sections. Sertoli cells expressed anti-Mullerian hormone (AMH), SOX-9, prostaglandin D synthase (Pgds) and bcl-2 (in four of four cases); sonic hedgehog (Shh) and p53 (in three of four cases) and androgen receptors (AR; in one of four cases). Ki-67 index ranged from 10% to 50%. Leydig cells expressed Shh and AR (two of two cases), while they showed no expression of p53, bcl-2 and 0% Ki-67 index. Granulosa cells expressed AMH, Pgds, Shh, estrogen receptors, progesterone receptors, AR and bcl-2 (in two of two cases) and p53 (in one of two cases). Ki-67 index was 10% and 40%, respectively. Further investigation is required to clarify the role of the molecules outlined above in the histogenesis of ovarian SCST, as Pgds-mediated SOX-9 upregulation could provide a reasonable explanation for the presence of testicular differentiation in ovarian SCST.     

Immunohistochemical demonstration of cytokeratins in endocrine cells of the human pituitary gland and in pituitary,adenomas

Summary Ten non-neoplastic pituitary glands and 22 pituitary adenomas producing different hormones were studied by immunofluorescence microscopy as well as peroxidase-antiperoxidase and biotin-avidin techniques on frozen sections and formalin-fixed, paraffin-embedded material using antibodies to cytokeratin, vimentin, GFAP, neurofilament protein and different pituitary hormones. The endocrine cells in non-neoplastic pituitary glands as well as in most pituitary adenomas were cytokeratin-positive. The cytoplasmic cytokeratin distribution patterns of non-neoplastic and tumor cells were similar and typical of the type of hormone produced: GH-producing normal cells showed a paranuclear condensation of cytokeratin-reactive intermediate filaments; this accumulation was even further accentuated in GH-producing adenomas resulting in fibrous bodies (Kovacs and Horvath 1978) decorated by cytokeratin antibodies. Prolactin-producing cells showed a less intense cytoplasmic cytokeratin-specific staining with focal paranuclear accentuation in non-neoplastic as well as in neoplastic glands. ACTH-producing cells in normal pituitary glands as well as in adenomas exhibited a strong and more uniform cytoplasmic cytokeratin staining. The cytokeratin reactivity in glycoprotein hormone-producing cells of non-neoplastic tissue and adenomas was weak. Vimentin and GFAP reactivity was confined to agranular folliculo-stellate cells. The specific and different distribution patterns of cytokeratins in pituitary cells can, therefore, provide an (indirect) indication to the production of a specific hormone if immunocytochemistry fails to demonstrate hormone production.Dedicated to Prof. Dr. J.H. Holzner on the occasion of his birthday     

Keratin and vimentin distribution patterns in the epithelial structures of the cannie anal region

The intermediate filament labeling pattern of the epithelial structures of the canine anal region was studied with different polypeptide specific keratin monoclonal antibodies (MoAbs) and with a monoclonal and polyclonal vimentin antibody. The epithelial structures in this region could be discriminated and characterized by differences in their keratin staining pattern. The basal cells in the different epithelial structures showed a similar staining pattern characterized by reactivity with MoAbs staining keratins 5, 8, 14, and 17. Columnar epithelial cells showed a completely different phenotype mostly characterized by reactivity with MoAbs staining keratins 7, 5, 8, 18, and 19. A restricted number of differentiated perianal gland cells showed perinuclear vimentin staining. Myoepithelial cells did not stain for vimentin, but, as other basal cells, were positive for MoAbs staining keratins 5, 8, 14, and 17.© Willey-Liss, Inc.     

Coexpression of cytokeratin,neurofilament and vimentin in carcinoid tumors

Summary The immunohistochemical expression of intermediate filaments was investigated in 56 carcinoid tumors from 50 cases including 31 rectal and 25 non-rectal sites. Cytokeratin was the most frequently expressed in 55 of the tumours. Only one tumour of the stomach was negative for cytokeratin. Neurofilament (68 kd and 160 kd) was positive in 25 (44.6%) tumours with no preferential pattern of expression in particular tumours. Vimentin was positive in 18 out of the 31 rectal carcinoids (58%), and 3 of the 25 non-rectal carcinoids (12%). There was a significant difference in vimentin immunoreactivity between rectal and non-rectal carcinoids. The coexpression of cytokeratin and neurofilament was 44.6% and that of cytokeratin and vimentin was 37.5%. The coexpression of all three types of intermediate filament was 35.5% in rectal carcinoids, but 8% in non-rectal carcinoids. The present study revealed coexpression of cytokeratin, neurofilament and vimentin in carcinoids and an especially high incidence of vimentin expression in those of rectal origin.     

Immunohistochemical studies of steroidogenic enzymes (aromatase, 17 alpha-hydroxylase and cholesterol side-chain cleavage cytochromes P-450) in sex cord-stromal tumors of the ovary

Aromatase, 17 alpha-hydroxylase, and cholesterol side-chain cleavage P-450 cytochromes (P-450AROM, P-450(17 alpha,) and P-450SCC, respectively) were immunohistochemically localized in nine granulosa cell tumors, 15 thecomas, ten Sertoli-Leydig cell tumors, two steroid cell tumors, five fibromas, and five sclerosing stromal tumors. In the thecomas, P-450SCC and P-450(17 alpha) were positive in luteinized theca cells and in cells with vacuolated cytoplasm, while P-450AROM was not observed. In the steroid cell tumors, all the P-450 cytochromes were intensely stained. P-450SCC and P-450(17 alpha) were present in cells with vacuolated cytoplasm in two cases of sclerosing stromal tumor. P-450AROM was weakly demonstrated in one of the granulosa cell tumors. P-450(17 alpha,) P-450SCC, and P-450AROM were all faintly stained in the Sertoli-Leydig cell tumors. No P-450 cytochrome immunoreactivity was observed in any fibroma.     

Uterine tumors resembling ovarian sex cord-stromal tumors: synchronous uterine tumors resembling ovarian sex cord-stromal tumors and ovarian sex cord tumor

Uterine tumors resembling ovarian sex cord-stromal tumors (UTROSCTs) are very rare. In this article, we present 3 cases that manifest classical histomorphological features alongside diverse immunohistochemical findings. As a distinctive finding, one of the patients had UTROSCT in the uterus and an ovarian sex cord tumor, called granulosa cell tumor, in the left ovary, simultaneously. Problems in diagnosing such pathologic condition generally arise because of the variable histologic picture of UTROSCT and may cause problems for general and other nongynecologic surgical pathologists. Immunohistochemically, these tumors express different markers that indicate their polyphenotypic origins.     

Structures mimicking sex cord-stromal tumours and gonadoblastomas in the ovaries of normal infants and children

A chance finding of structures resembling gonadoblastomas in the ovaries of a child with lissencephaly prompted a detailed review of all ovarian histology obtained at autopsy over a 12 month period. Fifty-five stillbirths, infants and children were studied ranging from 20 weeks gestational age to 2.5 years post-natal age. In 19 infants structures mimicking gonadoblastomas and sex cord tumours with annular tubules were seen. In all but one case these structures were found in association with follicular cysts and they closely resembled the atretic follicles often seen in the stroma surrounding the follicular cysts. They differed from the atretic follicles only by virtue of their being larger. In addition, in several infants structures resembling Sertoli cell tubules or clusters of Leydig cells were found. When present, these structures always co-existed with sex cord tumours with annular tubules and gonadoblastoma-like lesions. The abnormal stromal lesions and follicular cysts were found most frequently at the stage of development when a massive 'physiological' reduction of oocytes occurs. It is suggested that the 'abnormal' structures identified in this report represent the 'first hit' of oncogenesis and could serve as the precursor of many of the sex cord-stromal tumours, and possibly germ cell neoplasms, seen in childhood.     

Co-expression of cytokeratin and vimentin intermediate-sized filaments in renal cell carcinomas

Summary The expression of intermediate-sized filaments (IF) was examined by immunocytochemical methods in 40 primary renal cell carcinomas and compared with the IF distribution in the normal adult human kidney. All tumours stained positively with cytokeratin IF antibodies. Co-expression of cytokeratins and vimentin was observed in 21/40 (52,5%) renal carcinomas. Double immunofluorescence labelling demonstrated that in most of these cases tumour cells contained both cytokeratin and vimentin type IF. In normal human kidneys, cells of the various tubular segments disclosed a positive reaction with cytokeratin antibodies in a different intensity and intracellular localization. Co-expression of cytokeratin and vimentin IF in normal adult human kidneys has never been observed. From a histogenetic point of view, co-expression of cytokeratins and vimentin in renal cell carcinoma obviously represents an atavistic phenomenon since vimentin is re-expressed by these tumour cells during neoplastic transformation. This finding indicates the metanephric origin of the renal parenchyma. In surgical pathology the possibility of very rare co-expression of cytokeratin and vimentin IF within tumour cells should be considered, particularly in the differential diagnosis of clear cell carcinomas.Dedicated to Prof. Dr. K. Goerttler on the occasion of his 60th birthday     

Immunohistochemical study of rhabdomyosarcoma. Unexpected staining with S100 protein and cytokeratin

The immunohistochemical study of 60 cases of rhabdomyosarcomas made it possible to test eight different antibodies currently used in tumour pathology: i.e., antisera to vimentin, desmin, myoglobin, cytokeratin, epithelial membrane antigen, S100 protein, neurofilaments, and leukocyte common antigen. Vimentin was found in 58 cases (97 per cent), desmin in 49 cases (82 per cent), myoglobin in 23 cases (38 per cent), S100 protein in 7 cases (12 per cent), and cytokeratin in 3 cases (5 per cent). Other markers were negative. S100 protein was present in large round tumour cells with abundant eosinophilic cytoplasm (round rhabdomyoblasts), whereas cytokeratin was present in small tumour cells similar to those observed in rhabdoid sarcoma. This unexpected staining should become common knowledge for the correct interpretation of the immunohistochemical study of small cell tumours in the young.     

The differentiation of the skin and its appendages. I. Normal development of papillary ridges

In the present study, the normal development of papillary ridges was studied in the volar pads of both fore and hindpaws of the opossum, Monodelphis domesticus. At birth, the developmental state of the opossum's paws is equivalent to that of a six-week human embryo. The development of papillary ridges in the opossum occurs entirely postnatally and the hindpaw lags behind the forepaw by at least four days in most developmental parameters. Papillary ridge formation is preceded by four events: skin innervation, Merkel cell differentiation, mesenchymal condensation, and epidermal proliferation. The apical pads at the tips of the digits and the interdigital pads between the heads of the metacarpals (or metatarsals) have a unique pattern of innervation and mesenchymal content as compared to the non-pad skin. Each pad is innervated by a prominent nerve trunk and axons ascend towards the epidermis providing a density of innervation that exceeds that in the non-pad epidermis. Merkel cells are absent in non-pad epidermis but present in the pads prior to the onset of formation of papillary ridges. A loose aggregation of mesenchyme forms the core of the pads and the superficial dermis is more cellular in the pads as compared to the equivalent dermis in surrounding non-pad skin. Developing papillary ridges always contained Merkel cell-axon complexes. Merkel cell axon complexes serve as the anatomical substrate of slowly adapting (SA) mechanoreceptors. The presence of these complexes during early skin differentiation is consistent with the use of the opossum's forepaw in climbing to the nipple, but also suggests other possible functions. We hypothesize that the nervous system might play a role in the timing or patterning of the formation of papillary ridges.     

The utility of calretinin, inhibin, and WT1 immunohistochemical staining in the differential diagnosis of ovarian tumors

Calretinin has been proposed as a novel marker of ovarian sex cord-stromal tumors (SCST); this study aims to determine whether calretinin can complement or supplant the established utility of inhibin in the differential diagnosis of SCST. WT1 has been shown to be expressed in ovarian serous, but not mucinous neoplasms; its expression in a variety of ovarian tumors is also examined. Formalin-fixed, paraffin-embedded archival tissues from 111 primary ovarian tumors were analyzed with commercially available antibodies using semi-automated immunohistochemistry. Results were graded on a 4-tiered scale with staining of more than 0 but less than 5% of cells considered focal. Of 27 SCST, 56% were calretinin and 56% inhibin positive overall; 90% of granulosa cell tumors, 57% of Sertoli-Leydig cell tumors, 33% of thecomas, and 14% of fibromas were calretinin positive. Inhibin was expressed in 60% of granulosa cell tumors, 71% of Sertoli-Leydig cell tumors, 43% of fibromas, and 33% of thecomas. Of 35 surface epithelial tumors (SET), 8% of serous papillary tumors were calretinin positive, whereas 8% of serous papillary tumors and 13% of poorly differentiated carcinomas expressed inhibin. WT1 was expressed in 29% of all endometrioid carcinomas, 10% of borderline mucinous tumors, and no mucinous carcinomas; however, most of the other SETs were positive (77% serous papillary and 88% poorly differentiated carcinomas). Among the SCST, WT1 stained only granulosa cell tumors (75%), though often weakly or variably. Calretinin has only slightly greater sensitivity (76% versus 65%) and equal specificity to inhibin (92%) in the differential staining of granulosa or Sertoli-Leydig cell tumors, that is, nonstromal SCST. Hence, calretinin cannot replace but could complement inhibin as part of an immunohistochemical panel used for diagnostically challenging SCST. Although WT1 should be reliably positive in non-mucinous SET, staining of granulosa cell tumors and lack of expression in a sizable subset of endometrioid carcinomas may confound interpretation.     

Mediastinal Tumors: Ultrastructural and Immunohistochemical Evaluation of Intermediate Filaments as Diagnostic Aids

The histogenesis of six mediastinal tumors was investigated ultrastructurally and immunohistochemically using monospecific antibodies against intermediate filament proteins. Four of the tumors, showing different appearances by light microscopy, displayed desmosomes and cytoplasmic tonofilaments, by electron microscopy, compatible with an epithelial thymoma. These cases also showed keratin positivity by immunofluorescence microscopy. One spindle cell tumor showed zonula adherens-type junctions, prominent collections of intermediate filaments, and abundant cytoplasmic neurosecretory granules consistent with a neuroendocrine tumor. In this tumor, neurofilaments could be demonstrated by immunofluorescence microscopy, a feature also consistent with a neuroendocrine tumor. One malignant tumor, lacking tonofilaments and desmosomes but showing a few primitive junctions, did not contain keratin but showed vimentin positivity. This suggests a mesenchymal origin and a diagnosis of primitive sarcoma. These cases illustrate the diagnostic usefulness of electron microscopy and immunohistochemical evaluation of intermediate filaments.     

Distribution of cytokeratin filaments and vimentin in developing human taste buds

 Taste buds in humans originate from approximately the 8th postovulatory week under the influence of ingrowing nerve fibers. Since they develop from local epithelium, it is of interest whether or not prospective taste cells maintain or develop characteristics of epithelial cells that are different from those of the adjacent epithelium during differentiation. The aim of this study was to monitor changes of the distribution of the cytokeratin filaments (CKs) 8, 18, 19 and 20 (”gastrointestinal” type), CK 7 (”ductal” type), and CK 13 (maturation ”mucosa type”), as well as vimentin in developing human taste buds and adjacent squamous epithelium. With the exception of CK13, which remains negative in taste bud anlagen and adult taste buds, all cytokeratins tested were present in taste cells. With the progress of development, the distribution of CKs becomes more and more restricted to taste cells and salivatory ducts as well as Ebner gland cells. Only CK20 is exclusively specific to taste bud anlagen and sometimes to individual bipolar cells occurring in early stages (week 8–9). Vimentin was located mainly in mesodermal derivatives but also in perigemmal epithelial cells during all stages of development. The occurrence of vimentin in ”borderline” epithelia that interface with underlying connective tissue, i.e., in a region of discontinuity, may be associated with particular events in development, cell migration or even dedifferentiation. Accepted: 17 September 1998     

Intermediate-sized filament proteins (prekeratin,vimentin, desmin) in the normal parotid gland and parotid gland tumours

Summary Antibodies to different intermediate-sized filament proteins can distinguish cells and tissues of epithelial, mesenchymal, muscle, astrocytic and neural origin. Antibodies to prekeratin, vimentin and desmin have been used to distinguish cells of epithelial, mesenchymal and muscle origin in the normal human parotid gland, and in addition to study some common tumors of this gland. Prekeratin-positive and vimentin-positive cells are found among the tumor cells in the pleomorphic adenomas. In contrast the tumor cells of the mucoepidermoid tumors and squamous cell carcinomas are prekeratin-positive but vimentin-negative.Supported by the Deutsche Forschungsgemeinschaft (Ca 93/1-1) and by the Hamburger Stiftung zur Förderung der Krebsbekämpfung