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R Moll

Publications and source records attributed to R Moll.

At least 181 records · Page 10Linked to original sources

[Primary larynx carcinoid. Case report and review of the literature].

Neuroendocrine tumours of the larynx are extremely rare. Only 20 cases of laryngeal carcinoid tumours have been reported. Since histological diagnosis is difficult, this unusual neoplasm was often misdiagnosed as an undifferentiated carcinoma. The case of a 72-year old man is reported, who was admitted to hospital after suffering from hoarseness and left-sided otalgia for 4 weeks. Indirect laryngoscopy showed a tumour at the left ary region. The tumour was removed endoscopically. The light and electron microscopic characteristics and the results of the histochemical examinations are reported. In a review of the literature, the data of the 19 previously published cases are discussed together with those of the present case.

Aged↗

Immunocytochemical study of an endometrial diffuse clear cell stromal sarcoma and other endometrial stromal sarcomas.

Intermediate filament composition was studied in the following endometrial stromal tumors: low-grade stromal sarcoma (endolymphatic stromal myosis), high-grade stromal sarcoma with an associated adenocarcinoma (collision tumor), diffuse clear cell stromal sarcoma and a mesodermal mixed tumor (carcinosarcoma). The tumor cells of the stromal tumors as well as the mesenchymal elements of the mixed mesodermal tumor were decorated exclusively with antibodies to vimentin. Desmin was not demonstrated in these tumor cells. A biochemical study of the cytoskeletal filaments present in the low-grade stromal sarcoma revealed, in addition to vimentin, beta and gamma actin as seen in normal endometrial stroma. Cytokeratins were only identified in epithelial components which were present in some of these tumors. Intermediate filament typing in these endometrial neoplasms contributes to the elucidation of histogenetic problems, may delineate mesenchymal from epithelial elements, may separate muscle from stromal lesions and in one instance helped to define a hitherto unreported diffuse clear cell stromal sarcoma.

Actins↗

Intermediate filaments and desmosomal plaque proteins in testicular seminomas and non-seminomatous germ cell tumours as revealed by immunohistochemistry.

Seminomas and non-seminomatous testicular germ cell tumours were studied for the presence of cytokeratin and vimentin filaments and desmosomes using immunohistochemical methods. In the majority of the classical seminomas and in seminomatous area of mixed tumours most tumour cells appeared to lack cytokeratin filaments. Some seminomas contained a focally variable proportion of cells exhibiting cytokeratin-positive structures while other cases contained only few seminoma cells with a well developed fibrillar cytokeratin network. Gel electrophoresis of cytoskeletal proteins from microdissected regions revealed cytokeratin polypeptides nos. 8 and 18 typical of simple epithelia. In one seminoma, however, all, or almost all, tumour cells contained cytokeratin filaments. This finding is in line with the assumption of transitional forms between seminoma and embryonal carcinoma. Despite the lack - or variable expression - of cytokeratin filaments most seminoma cells contained desmosomes, although often few in number and irregularly distributed at the circumference of the cells. Loosely arranged and often very sparse vimentin fibrils were found in many, but not all seminoma cells. Double label immunofluorescence microscopy suggested that the majority of desmosomes was associated with intermediate filaments of the vimentin type. In contrast, in carcinoma cells of malignant teratomas, in well differentiated epithelial cells of intermediate-type malignant teratomas and in trophoblastic cells present in trophoblastic-type malignant teratomas cytokeratin filament bundles as well as desmosomes were decorated. The arrangement and density of the cytokeratin filament skeleton and of desmosomes varied with degree of maturation of the tissue. The most regular distribution and intensive staining of cytokeratin filaments and desmoplakin was found in "mature" tissues. Vimentin was demonstrated in mesenchymal areas and stroma cells. The results show that seminomas are distinguished from most other germ cell and non-germ cell tumours by the presence of true desmosomes together with scanty vimentin filaments in most tumour cells. In addition, they indicate that seminoma cells can be heterogeneous in their cytoskeletal complement and may include cells with cytokeratin expression, indicative of a multipotential character of the initially transformed cell(s).

Adolescent↗

The establishment of two rat colonic carcinomas in tissue culture. A basic prerequisite for standardized experiments on the biology of colonic carcinomas in vivo.

Two rat colonic carcinomas (DMH-Co-1 and DMH-Co-2) derived from dimethyl-hydrazine-induced metastasizing adenocarcinomas were established as permanent cell lines. By means of electron microscopy, immunofluorescence microscopy and biochemical analysis of cytoskeletal components, it has been shown that both tumor cell lines retain in vitro the phenotypic characteristics of the primary tumors. The in vitro growth properties revealed only minor differences between the two cell lines. After retransplantation in vivo, DMH-Co-2 gave rise to moderately differentiated adenocarcinomas, whereas the tumors arising from DMH-Co-1 exhibited a continuum of differentiation encompassing adenocarcinomas, undifferentiated carcinomas and squamous cell carcinomas. These permanent cell lines offer the opportunity for isolating divergent subpopulations by in vitro cloning and facilitate standardized experiments on their biological behaviour in vivo.

Adenocarcinoma↗

Characterization of subcolumnar reserve cells and other epithelia of human uterine cervix. Demonstration of diverse cytokeratin polypeptides in reserve cells.

We have analyzed the expression of cytokeratin polypeptides in subcolumnar reserve cells of the human uterine endocervical mucosa and the other epithelial cells using immunoperoxidase and immunofluorescence microscopy as well as by applying two-dimensional gel electrophoresis to microdissected cytoskeletal preparations. Endocervical columnar cells were uniformly positive for antibodies directed against the simple epithelium-type cytokeratins nos. 7, 8, 18, and 19, while a variable proportion of these cells was stained by an antibody against cytokeratin no. 4. Reserve cells were not only positive for cytokeratins nos. 8 (weakly and variably) and 19 but were also decorated by antibody KA 1, which reacts with cytokeratins present in stratified squamous epithelia. This last antibody selectively decorated reserve cells even when they were flat and inconspicuous. Antibody KA 1 uniformly stained the ectocervical squamous epithelium, the basal cells of which were also decorated by antibodies directed against cytokeratins nos. 8 (weakly and variably) and 19. Ectocervical suprabasal cells were positive, to a variable extent, for antibodies against cytokeratins nos. 4, 10/11, and 13. Gel electrophoresis revealed the presence of squamous-type cytokeratins nos. 5 and 17 in reserve cell-rich, but not in reserve cell-free, endocervical mucosa. We also analyzed the distribution pattern of these cells, as revealed by antibody KA 1, in the endocervical mucosa of 26 uteri. In all the specimens examined reserve cells were present, but their numbers exhibited considerable variation. In some cases these cells were confined to small islets localized deep within the cervical canal and lacked any continuity with the squamous epithelium. The expression of cytokeratins nos. 5 and 17 in reserve cells indicates that these cells have undergone a low level of squamous differentiation. The additional expression of cytokeratins nos. 8 and 19 in these cells points to a relationship with simple epithelial cells. The present data would seem to favor the view that reserve cells originate in situ from the columnar epithelium; however, this would imply an acquisition of new differentiation properties.

Adult↗

Villin: a cytoskeletal protein and a differentiation marker expressed in some human adenocarcinomas.

We studied the expression of villin, a microfilament-associated, actin-binding protein typical of brush-border microvilli, in a variety of human carcinomas by applying immunofluorescence microscopy to frozen sections and immunoblotting methods to tissue extracts using a rabbit antiserum and a monoclonal antibody specific for villin. All of the 24 primary and metastatic colorectal adenocarcinomas tested were uniformly and strongly positive for villin, with the immunocytochemical labeling concentrated at the luminal cell margin. In poorly differentiated tumor areas, rudimentary tubules were stained. All of the six tubular adenocarcinomas of the stomach studied as well as two adenocarcinomas of the gall bladder and a hepatocellular carcinoma were also villin-positive. Villin was detectable in 12 of 14 adenocarcinomas of the pancreas; in some of these cases, its distribution was heterogeneous. Among 21 renal cell carcinomas investigated, positivity for villin was seen in nine of 13 clear cell tumors (especially those of grade II), and in all four chromophilic cell tumors; however, all four chromophobe cell tumors studied were negative. Four of 11 endometrial but none of nine ovarian carcinomas were (uniformly or focally) villin positive. Of 18 adenocarcinomas of the lung studied, one was uniformly and four focally positive for villin, while the remainder were negative. All of the other epithelial tumors studied, including 12 adenocarcinomas of the breast and seven epithelial or biphasic pleural mesotheliomas, were villin negative. Our results show that the expression of villin in intestinal epithelial cells is consistently maintained in their corresponding carcinomas, even when the organized brush-border structure has been lost. The presence of villin in some endometrial and pulmonary adenocarcinomas--in contrast to its absence in the respective normal epithelia--suggests that this protein is newly expressed during hyperplasia, dysplasia, or carcinogenesis. Determining the presence or absence of villin and its immunocytochemical staining pattern in metastatic adenocarcinomas may be of some help in determining the type and site of the primary tumor.

Adenocarcinoma↗

[Merkel cell carcinoma of the upper eyelid].

Case report of a rare eyelid tumor in an 83-year-old woman. The excised lesion was classified as a neuroendocrine Merkel cell carcinoma on the basis of histologic, ultrastructural, and immunohistochemical examination. Detection of neurosecretory granules by electron microscopy and the characteristic cytokeratin and neurofilament pattern supported the diagnosis. The patient developed a local recurrence, which was successfully removed. There is no evidence of regional or distant metastases.

Aged↗

Synaptophysin expressed in the bronchopulmonary tract: neuroendocrine cells, neuroepithelial bodies, and neuroendocrine neoplasms.

Synaptophysin is an integral membrane glycoprotein with an Mr of 38,000 that occurs in the small, clear vesicles present in neuronal cells and tumors as well as in pancreatic islet cells and various neuroendocrine (NE) carcinomas. We found that synaptophysin is also expressed in normal NE cells of the lungs of newborn rabbits and mice as well as of human fetuses. In bronchial ganglion cells and in nerves, synaptophysin is coexpressed with neurofilament proteins (NFPs), whereas in solitary NE cells and in at least some of the neuroepithelial bodies (NEBs) of the bronchial mucosal lining, synaptophysin coexists with cytokeratins. We also studied a series of NE neoplasms of the lung covering the entire spectrum of differentiation (i.e., from carcinoids to small-cell NE carcinomas), and found that synpatophysin was present in the majority of them. In these tumors, synaptophysin was invariably coexpressed with cytokeratin filaments and desmoplakin, as well as, occasionally, with NFP. Synaptophysin was identified throughout, the whole range of these NE neoplasms, i.e., from benign to low-grade to aggressive and rapidly metastasizing carcinomas; its presence was unaffected by the highly variable expression of serotonin and/or neuropeptides in these neoplasms, and was unrelated to the presence or absence of associated endocrine syndromes. Our findings indicate that synaptophysin occurs in the neural as well as in the epithelial components of the dispered NE system of the lung as well as in the majority of NE neoplasms of this organ, and that the expression of this protein is therefore independent of the cytoskeletal characteristics and other differentiation features of both normal and transformed NE cells of the lung. We emphasize the value of synaptophysin as an immunocytochemical marker of NE differentiation.

Animals↗

Cytoskeletal components of lymphoid organs. I. Synthesis of cytokeratins 8 and 18 and desmin in subpopulations of extrafollicular reticulum cells of human lymph nodes, tonsils, and spleen.

Using light and electron microscopic immunolocalization with antibodies to cytoskeletal proteins, we have characterized the nonlymphoid cells of various human lymphoid organs (lymph nodes, tonsils, spleen). In all these tissues, the lymphoid follicles contain a three-dimensional meshwork of "dendritic reticulum cells" which are characterized by the presence of desmosomal junctions, as demonstrated by positive punctate staining with antibodies to the desmosome-specific proteins desmoplakin I and desmoglein, and by intermediate-sized filaments (IFs) of the vimentin type only. In contrast, the extrafollicular regions are characterized by an extended meshwork of other types of reticulum cells, which also contain vimentin IFs but lack desmosomal proteins. In addition, a considerable, although variable proportion of these extrafollicular reticulum cells forms IFs containing cytokeratins 8 and 18 and/or desmin-containing IFs. The occurrence of cytokeratins 8 and 18 in lymph nodes has also been shown by gel electrophoresis and immunoblotting. Results of double-label immunolocalization indicate that some of the extrafollicular reticulum cells coexpress all three kinds of IF protein. A large proportion of these cells also synthesizes another marker of myogenic differentiation, i.e., the isoform of alpha-actin specific for smooth muscle. This proportion includes some cells that are negative for desmin. Comparison of the distribution of cells expressing cytokeratins and/or desmin with that of reticulum cells showing strong alkaline phosphatase activity (as a marker for the so-called "fiber-associated (fibroblastic) reticulum cells") suggests that the former represent a subset of the latter. The biological meaning of these different patterns of expression in reticulum cells and of the resulting cell-type heterogeneity as well as possible implications of these observations for tumor diagnosis, notably of lymph-node metastases and lymphomas, are discussed.

Adult↗

Distribution of a special subset of keratinocytes characterized by the expression of cytokeratin 9 in adult and fetal human epidermis of various body sites.

Biochemical analyses have previously shown that palmar and plantar epidermis, unlike the epidermis of other body sites, contain cytokeratin 9 (Mr 64,000), an unusually large acidic (type I) cytokeratin. Guinea-pig antibodies that specifically and selectively react with bovine and human cytokeratin 9 were used for the immunocytochemical identification of cytokeratin 9 in adult and fetal human epidermis from various body sites. In the epidermis of palms and soles, antibodies against cytokeratin 9 stained a high proportion of the keratinocytes in suprabasal locations. These suprabasal cytokeratin-9-positive keratinocytes were often arranged in vertical columns and concentrated around intraepidermal sweat-gland ducts, but they sometimes also formed extended continuous sheets. In contrast, another type-I component, cytokeratin(s) 10/11, was uniformly distributed among suprabasal keratinocytes. By double-labeling immunofluorescence microscopy using a monoclonal antibody against cytokeratin(s) 10/11, we found that cytokeratin 9 usually appears in cells located one or two layers above the cells in which cytokeratin(s) 10/11 is detected, indicating that most keratinocytes expressing cytokeratin 9 also express cytokeratin(s) 10/11. At other body sites, cytokeratin 9 was only detected in sparsely distributed keratinocytes localized in upper epidermal layers; these cells were scattered or formed small clusters, and often exhibited a conspicuous association with the epidermal portion of eccrine sweat-gland ducts. During human fetal development, cytokeratin 9 was first detected at week 15 of gestation in some suprabasal cells of the foot-sole epidermis and, occasionally, in basal cells. At later fetal stages, most of the cytokeratin-9-positive cells appeared in clusters that were mainly concentrated in glandular ridges and interridges. Our results show that two major types of terminally differentiating keratinocytes can be distinguished in human epidermis, i.e. those that do and those that do not express cytokeratin 9. This special program of keratinocyte differentiation identified by the presence of cytokeratin 9 appears to be related to the morphogenesis of palm and sole epidermis, where this protein is expressed early in fetal life. Possible biological functions of this subset of cytokeratin-9-positive keratinocytes are discussed.

Adult↗

Immunocytochemical analysis of Ewing's tumors. Patterns of expression of intermediate filaments and desmosomal proteins indicate cell type heterogeneity and pluripotential differentiation.

Examples of classical Ewing's tumors ("Ewing's sarcomas") of both skeletal and extraskeletal locations were analyzed for the expression of intermediate filament (IF) and cell junction proteins, with the use of immunofluorescence and immunoelectron microscopy as well as gel electrophoresis. In all 11 tumors examined vimentin filaments were abundant. A type of plaque-bearing small cell junction, which is common in these tumors but difficult to classify by morphologic criteria, was identified by antibodies to desmoplakins as true desmosomes. These were found in all cases, although in a very variable proportion of cells. Some of these junctions were associated with vimentin IFs. In addition, 9 of the cases examined showed scattered or clustered cells expressing the simple-epithelium type cytokeratins 8 and 18. Moreover, 3 cases displayed dispersed or clustered cells producing neurofilaments. The value of these observations, notably the cell type heterogeneity, for the diagnosis of tumors of this group is discussed. The results further indicate that Ewing's tumors are derived from a primitive, pluripotential cell that may differentiate, in variable proportions, into cells with mesenchymal, epithelial, and, more rarely, even neural features, suggesting that this tumor should be regarded as a blastoma, rather than as a true sarcoma.

Adolescent↗

Expression of intermediate filament proteins in subtypes of renal cell carcinomas and in renal oncocytomas. Distinction of two classes of renal cell tumors.

We examined the expression of the diverse cytokeratin (CK) polypeptides as well as vimentin in human renal cell carcinomas of various subtypes and in renal oncocytomas by applying both two-dimensional gel electrophoresis and immunocytochemistry by using polypeptide-specific monoclonal antibodies. The tumors were classified according to the guidelines of the World Health Organization, with some modifications based primarily on recently proposed cytomorphological criteria. All clear cell carcinomas (G I, G II; N = 20) co-expressed CKs nos. 8 and 18, and vimentin, with CK no. 19 being present in 13 of the 20 cases and exhibiting a heterogeneous distribution. Dedifferentiated carcinomas (G III; N = 8) also co-expressed CKs nos. 8 and 18 as well as vimentin, but in addition, exhibited CK no. 19 and, in many cases, CK no. 7; in 1 case, only vimentin was expressed. Both eosinophilic-granular (N = 3) and basophilic (small cell cuboidal; N = 6) carcinomas contained CKs nos. 8 and 18, and the co-expression of vimentin was a consistent feature of these tumors; CK no. 19 was found in all of these cases, while CK no. 7 was present in the majority. In chromophobe cell carcinomas (N = 8), in contrast to all of the other carcinoma types, no vimentin was detected in the tumor cells, with only CKs nos. 8, 18, and to a variable extent 7, being present. Similarly, oncocytomas (N = 8) lacked vimentin and exhibited only CKs nos. 8 and 18. Conspicuous scattered CK no. 19-positive cells were found in these two last tumor types. No CK polypeptides other than simple-epithelium-type CKs (nos. 7, 8, 18, and 19) were detected in any of the tumors studied. These results indicate that, in renal cell tumors, the expression of intermediate-filament proteins is strikingly correlated with the specific morphologic appearance. While the co-expression of CKs nos. 8 and 18 and vimentin was a surprisingly consistent feature of the most common subtypes of renal cell carcinomas, CK no. 19 exhibited remarkable heterogeneity of expression both within individual tumors and between different tumors, the expression patterns of this CK being correlated to the tumor subtypes. The consistent absence of vimentin in chromophobe cell carcinomas and oncocytomas makes it possible to define these as a separate class of renal cell tumors. This finding supports the view that chromophobe cell carcinomas represent a distinct tumor entity and points to their close phenotypic relationship to benign oncocytomas as well as to normal renal tubules.

Adenoma↗

Synaptophysin expression in neuroendocrine neoplasms as determined by immunocytochemistry.

Synaptophysin is an integral membrane glycoprotein originally isolated from presynaptic vesicles of bovine neurons. The authors have studied a wide spectrum of neuroendocrine (NE) neoplasms by immunofluorescence microscopy on cryostat sections of freshly frozen tissues using a monoclonal antibody to this protein (SY 38). Without exception, they found the identical--or a very similar--protein expressed in all neuroblastomas, ganglioneuroblastomas, ganglioneuromas, pheochromocytomas, and paragangliomas studied. In these "neural" type NE neoplasms, synaptophysin was coexpressed with neurofilament proteins. Synaptophysin was also demonstrated in NE neoplasms of "epithelial" type in which it was predominantly coexpressed with cytokeratins and desmoplakin. It was invariably found in all variants of islet cell neoplasms and in all medullary thyroid carcinomas. Synaptophysin was also demonstrated in several adenomas of the hypophysis and parathyroids, in the majority of carcinoids of the bronchopulmonary and gastrointestinal tracts, and in many, though not all, NE carcinomas of the same sites, and of the skin. Conversely, SY 38 did not immunostain any of a large number of benign and malignant non-NE epithelial neoplasms; nor was any immunostaining obtained in a group of mesenchymal tumors. It is remarkable that SY 38 did not immunostain a number of malignant melanomas, including several that were immunostained for neuron-specific enolase (NSE) and several neuropeptides. Parallel studies conducted on conventionally fixed, paraffin-embedded tissue sections immunostained by the use of the avidin-biotin complex technique yielded very similar results. The findings indicate that synaptophysin is expressed in the whole range of NE neoplasms without detectable relation to the expression of other NE markers such as NSE, serotonin, and neuropeptides. Nor could the expression of synaptophysin by these tumors be correlated with their epithelial and/or neural cytoskeletal characteristics, their clinical aggressiveness, or the presence or absence of endocrinologic abnormalities. While the consistent expression of synaptophysin by the "neural" type of NE neoplasms would seem predictable its presence in diverse benign and malignant NE tumors of "epithelial" type is remarkable. It is concluded that synaptophysin is a significant as well as novel NE marker, and the use of antibody SY 38 as a broad range marker for the study and diagnosis of NE neoplasms is proposed.

Endocrine System Diseases↗