Estudio inmunohistoquímico en rabdomiosarcoma / Immunohistochemical study in rhabdomyosarcoma

Se realizó el estudio inmunohistoquímico de 32 rabdomiosarcomas haciendo uso de diversos marcadores del tejido conectivo empleando la técnica de PAP, método que ofrece una mayor precisión en la caracterización morfológica de los tumores de origen mesenquimatoso, con el fin de brindar una información que contribuya a un mejor diagnóstico y clasificación de esta entidad estudiada. Se destaca la importancia de la desmina como un marcador que se expresa en estadios muy tempranos de la diferenciación en los tumores de origen muscular. Además se discute el origen de la variante histología del Rabdomiosarcoma pleomórfico a partir de una célula madre capaz de expresar los diferentes marcadores que identifican las estirpes celulares de los 4 tejidos básicos.

Combined treatment of rat rhabdomyosarcoma R1H with mitomycin C and X-rays.

The effects of mitomycin C (MTC) alone and in combination with radiation on R1H rhabdomyosarcomas in WAG/Rij rats were studied. Growth delay was determined from tumor volume growth curves and proportion of tumor and host cells from flow cytometry measurements. Only minor growth delays were obtained with MTC at doses near the toxic level while irradiation applied in three fractions of 10 Gy in three weeks yielded growth delays of 27, 44, and 51 days measured at volumes of 2, 5, and 10 cm3, respectively. The combination of 1 micrograms/kg b.w. MTC and 10 Gy irradiation given in three weekly fractions resulted in 21, 28, and 29 days growth delay for the above tumor volumes. The lower effect of combination as compared to irradiation alone is discussed with the flow cytometry data. These data show that early after start of treatment the proportion of tumor cells remains constant in contrast to radiation alone where the fraction of tumor cells decreases because of influx of granulocytes and macrophages into the tumor. In contrast to the reduced effect on tumors the combination treatment was considerably more toxic for the animals than the single treatments.

12-O-tetradecanoylphorbol-13-acetate-induced differentiation of a human rhabdomyosarcoma cell line.

The effect of 12-O-tetradecanoyl phorbol-13-acetate (TPA) on proliferation and differentiation of the human embryonal rhabdomyosarcoma cell line RD was investigated. The proliferation of RD cells is drastically and reversibly inhibited by 100 nM TPA. The effect is evident after 24 h of treatment and is maximal after 50-70 h. The reduction of proliferation in treated cells is followed by increased expression of differentiative characters such as a large increase in muscle myosin expression and in the binding of 125I-alpha-bungarotoxin. Moreover TPA induces the appearance of myotube-like structures, which contain bundles of thick and thin myofilaments along with Z bodies. The described effects are not observed if the TPA-containing medium is replaced daily, thus suggesting that these effects might be related to substances secreted by treated cells. The phosphorylation of three proteins is significantly stimulated by TPA within minutes of its administration to RD cells. Although with a different pattern, the stimulation of protein phosphorylation is still clearly detectable after 6 days of incubation with TPA. These results on human rhabdomyosarcoma cells are, to our knowledge, the first evidence for a growth-inhibiting and a differentiative effect of TPA on a solid tumor of mesodermal origin.

Rabdomiosarcoma en el adulto / Rhabdomyosarcoma in the adult

Se hace un análisis clinicopatológico e inmunoquímico de 23 rabdomiosarcomas en adultos, diagnósticados en el INOR en el período de 1971 a 1987. En ninguno de ellos se encontraron estriaciones transversales y las reacciones con desmina y mioglobina resultaron negativas. Los marcadores de histiocitos son positivos en las células tumorales de los 6 casos estudiados. Se rechaza el diagnóstico de rabdomiosarcoma pleomórfico y se admite el de histiocitoma fibroso maligno. Se comentan los criterios contemporáneos para el diagnóstico del rabdomiosarcoma y la posible relación entre éste y el histiocitoma fibroso maligno

Hyaluronate-binding proteins in weakly and highly metastatic variants of rat rhabdomyosarcoma cells.

Weakly (RMS8) and highly (RMS0) metastatic rat rhabdomyosarcoma cells were assayed for their interaction with hyaluronate. The cells in subconfluent cultures were incubated with 35S methionine, the cells were fractionated and the labelled proteins were separated by affinity chromatography on hyaluronate-Sepharose and by HPLC. The RMS8 cells expressed about twice the amount of labelled hyaluronate-binding proteins seen in the RMS0 cells. The molecular sizes of the main hyaluronate-binding proteins were similar in both cell types. Unlike the RMS0 cells, the RMS8 cells took up exogenous, radioactively labelled hyaluronate at 4 degrees C in a saturable and specific way with high affinity. Cells were also incubated with 3H glucosamine. The isolation of the glycosaminoglycans from these cultures by ion-exchange chromatography indicated that the RMS8 cells retained more endogenous 3H hyaluronate in their pericellular domain than did the RMS0 cells. The attachment of trypsinized cells could be inhibited with exogenous hyaluronate, indicating that the proteins with affinity for hyaluronate may act as hyaluronate-binding sites on these cells.

The diagnostic utility of desmin. A study of 584 cases and review of the literature.

The diagnostic utility of several antibodies against desmin and their optimal staining conditions have not been systematically evaluated. Sections of paraffin-embedded tissues from 584 cases were stained with a monoclonal antibody against desmin (Clone DER 11 from DAKO), using an avidin-biotin-peroxidase technique. The results were tabulated and compared with those from previous reports. The following observations were made: (1) When pronase digestion was performed before staining, desmin was equally demonstrable in tissues fixed in formalin, Zenker's, Bouin's, or B5 fixative; however, desmin staining was lost or significantly diminished in tissues fixed in absolute ethyl alcohol. In contrast, when pronase was not used, a positive staining was demonstrated only in tissue fixed in absolute ethyl alcohol. (2) Positive staining was found in normal muscle (92 of 92 cases), leiomyoma (12 of 13), rhabdomyoma (6 of 6), rhabdomyosarcoma (31 of 31), leiomyosarcoma (18 of 26). (3) Desmin was never found in epithelia, normal mesenchymal tissue other than muscle, tumors stimulating rhabdomyosarcoma, and epithelial tumors. (4) A positive staining was documented in 1 tumor (a fibrous histiocytoma) of 42 benign predominantly spindle cell tumors and in 8 of 89 predominantly spindle cell sarcomas. (5) Desmin was never documented in myoepithelial cells but stained myofibroblasts in 2 of 12 examples of granulation tissue and in 29 of 67 samples containing tumor-associated desmoplasia. The authors' data on the diagnostic sensitivity and specificity of the evaluated antibody should improve the use of desmin in diagnostic pathology.

Tumores malignos de partes blandas estudio-clinico-patologico de 99 casos / Maling tumour of softhy parts: clinic patologic-study of 99 cases

Se presenta una revision de los tumores malignos de partes blandas en tres hospitales de la ciudad de La Paz, en un periodo de cinco a diez años. Las neoplasias mas frecuentes son el rabdomiosarcoma, el fibrosarcoma y el liposarcoma. Se presenta la frecuencia por sexo, edad, localizacion anatomica y, en algunos casos, el subtipo histologico. Se discuten los pocos casos diagnosticados como mesenquimoma maligno y del sarcoma indiferenciado. Los resultados se comparan con casuisticas de exterior

Rabdomiossarcoma ocular: estudo clínico de 12 casos / Ocular rabdomiossarcoma: clinical study of 12 cases

Foram avaliados 12 pacientes com rabdomiossarcoma ocular em relaç*o aos seguintes dados: sexo, idade, raça, tempo de história, localizaçäo do tumor, exame ocular e estudo anatomopatológico. Os resultados mostraram-se concordantes com a literatura. 8 casos tiveram um seguimento adequado tendo sido analisados em relaçäo ao tratamento, evoluçäo e complicaçöes. Os 2 pacientes que foram a óbito tinham sido submetidos a radioterapia isoladamente. A paciente que recebeu radioterapia e quimioterapia associada a exenteraçäo respondeu bem à terapêutica e pode ser considerada curada. Os demais pacientes foram tratados com quimioterapia e radioterapia, näo tendo apresentado recorrências até o momento, sendo que os autores concluem ser este o melhor esquema terapêutico

Immunohistochemical study of uterine stromal sarcoma and rhabdomyosarcoma.

The cytoplasmic filament composition of two pure high-grade endometrial stromal sarcomas and five pure endometrial rhabdomyosarcomas was studied using the immunoperoxidase avidin-biotin method. Ultrastructural correlates were performed on the same tissues. While four of the seven tumors presented as high-grade undifferentiated neoplasms, they were readily categorized on the basis of immunocytochemical findings in which the five rhabdomyosarcomas were positive for muscle-specific actin (HHF 35) and the two stromal sarcomas were positive for vimentin only. Ultrastructure on the HHF 35-positive cases showed the presence of thick filaments and Z-band material, whereas the other tumors showed no cytoplasmic differentiation. Muscle-type actin differs stromal cells, and is useful when used in conjunction with a panel of antibodies in the categorization of undifferentiated endometrial sarcomas.

Expression of actin isoforms and intermediate filament proteins in childhood orbital rhabdomyosarcomas.

The diagnosis of orbital rhabdomyosarcoma (RMS) in childhood gives rise to several clinical and anatomo-pathological problems. Antibodies recognizing structural proteins and cytoskeletal components have been shown to increase the diagnostic accuracy of different neoplastic lesions. In this study we examined anatomo-clinically and, where possible, by means of immunohistochemistry and electron microscopy, a series of 14 cases of orbital RMS in childhood. In the 12 cases studied by immunohistochemistry, desmin was always present, although showing variable patterns, and alpha-sarcomeric actin was found in 10 cases. alpha-Smooth muscle actin was always absent. The other markers tested (myoglobin, polyclonal actin, vimentin and enolase) proved unreliable for several reasons. We conclude that antibodies against desmin and alpha-sarcomeric actin are useful for the diagnostic definition of RMS. In addition, immunohistochemical analysis supplies data regarding the degree of tumor differentiation and may be applied to monitor radio- and chemotherapy.

Rhabdomyosarcoma in middle-aged and elderly individuals.

In a review of a national series of malignant tumors in middle-aged and elderly individuals (over 40 years of age), in all 107 cases primarily diagnosed and reported to the Swedish Cancer Registry as rhabdomyosarcomas during the period 1972-1981, 4 cases were accepted as botryoid, embryonal or alveolar rhabdomyosarcoma, using light-microscopic criteria for the diagnosis. An electron-microscopic and immunohistochemical analysis was performed on the 4 cases along with 7 cases of botryoid, embryonal and alveolar rhabdomyosarcoma in patients of over 40 years of age obtained from our own files. Rhabdomyoblastic differentiation was established ultrastructurally by the presence of myofilaments and Z-like densities in 10 of these 11 cases. There were tumor cells in the formaldehyde-fixed, paraffin-embedded material which were positively stained for desmin in all cases, for myoglobin in 7/11 cases, for vimentin in 5/11 cases and for actin in all cases, using monoclonal antibodies. The demonstration of desmin by the monoclonal antibody which was used on the formaldehyde-fixed, paraffin-embedded material is of particular value in the diagnosis of rhabdomyosarcoma. Another tumor, located in the minor pelvis, lacked the light-microscopic features of botryoid, embryonal or alveolar rhabdomyosarcoma, but presented ultrastructural and immunohistochemical evidence of a rhabdomyoblastic differentiation. This tumor was epithelioid in appearance and shared features with alveolar soft part sarcoma. The label epithelioid rhabdomyosarcoma is proposed for this tumor. Nine pleomorphic sarcomas were selected from the national series as possible pleomorphic rhabdomyosarcomas because of the presence of ribbon-shaped tumor cells with an eosiniphilic cytoplasm. There was no electron-microscopic or immunohistochemical evidence of a myogenic differentiation in any of these 9 tumors. The present investigation indicates that a pleomorphic type of rhabdomyosarcoma, indistinguishable from embryonal, botryoid and alveolar rhabdomyosarcoma, is extremely rare or non-existent.

Immunohistochemical spectrum of rhabdomyosarcoma and rhabdomyosarcoma-like tumors. Expression of cytokeratin and the 68-kD neurofilament protein.

Twenty-five rhabdomyosarcomas (RMSs), including 12 alveolar and 13 embryonal types, were immunohistochemically studied for the presence of different classes of intermediate filament proteins and muscle actins (MAs). For the most part, formaldehyde-fixed and paraffin-embedded tissue was used in immunostaining. All RMSs showed desmin and MAs, usually in a major portion of tumor cells. The number of MA-positive cells was sometimes higher than that of desmin-positive cells. Vimentin was present in all tumors studied in frozen sections. Eight of 12 alveolar RMSs showed small number of cytokeratin-positive neoplastic cells. Cytokeratin-positive cells were present less commonly in embryonal RMS (3/13 cases). The 68-kD neurofilament protein was found in frozen sections of two embryonal RMSs. The cytokeratin and neurofilament immunostaining could be reproduced by immunofluorescence technique. In addition, we studied three childhood sarcomas, which showed abundant desmin and MA immunostaining but did not conform to the ultrastructural criteria of RMS. Scattered cytokeratin-positive cells were found in two of these tumors, and neurofilaments were found in the two cases for which frozen sections were available. The results show that typical RMS may demonstrate immunohistological pleomorphism with cytokeratin and neurofilament immunoreactivity suggesting the presence of multidirectional differentiation. In addition, there are tumors that by morphology look like RMS and have muscle cell markers but cannot be verified as RMS by electron microscopy; also, these tumors seem to show immunohistological pleomorphism. The presence of nonmyoid markers in RMS should be considered when making immunohistological diagnosis of soft tissue sarcomas.

[Malignant peripheral neuroectodermal tumors. Histological and immunohistological conditions in 41 cases]. / Maligne periphere neuroektodermale Tumoren. Histologische und immunohistochemische Befunde an 41 Fällen.

In view of the personal observation that malignant peripheral neuroectodermal tumours (MPNT) can present different histological growth patterns, 41 cases of MPNT were histologically and immunohistochemically studied. The median age of the 41 patients was 15 years (range: 9 months - 23 years). There were 27 males and 14 females. Most tumours (23/41) were located in the thoracopulmonary region. In 31/41 cases there was bone as well as soft tissue involvement. The following histopathological patterns were found: Ewing's sarcoma-like (n = 7), atypical Ewing's sarcoma-like (n = 4), neuroblastoma-like (n = 8), rhabdomyosarcoma-like (n = 8), and hemangiopericytoma-like (n = 1). In 2 cases combined patterns were noted, one tumour being characterized by neuroblastoma-like and Burkitt's lymphoma-like features. Most cases of MPNT differed from the cytological features of typical Ewing's sarcoma in that they contained hyperchromatic nuclei with distinct nucleoli. Some reticulin fibrils were found in between the cells of some cases. Immunohistochemically, 19/23 cases reacted positively to vimentin, 29/32 to neuron specific enolase (NSE), 16/28 to protein S-100, and 1/9 to glial fibrillary acidic protein. 12/24 cases reacted positively to NSE and protein S-100. Neurofilaments and desmin were not found in the formalin fixed material of the present study. The results show that most cases of MPNT can be distinguished from typical Ewing's sarcoma by cytological and histological findings. Differential diagnosis from atypical Ewing's sarcoma, neuroblastoma, and rhabdomyosarcoma is possible by immunohistochemistry.

Myoglobin: an evaluation of its role as a marker of rhabdomyosarcomas.

Tumour markers now have an established role in tumour diagnosis and patient management. However, antibodies used to detect these tumour markers have in some instances proved unreliable, with a low rate of sensitivity and specificity. In this study we wished to evaluate the role of a commercial antibody to myoglobin as a marker of rhabdomyosarcomas. The purpose of this investigation was to assess the sensitivity and specificity of myoglobin antiserum as a marker of rhabdomyosarcomas. This was performed by reacting a large number of tumours (sarcomas, carcinomas and melanomas) with a polyclonal anti human myoglobin antiserum. Staining was demonstrated in 60% of rhabdomyosarcomas. Only two tumours from a total of 226 non-skeletal muscle tumours showed a positive reaction (0.88%). One was a leiomyosarcoma and the other had been classified as an undifferentiated sarcoma but a rhabdomyosarcoma was included in its differential diagnosis. It is of interest that both had been earlier irradiated. This antiserum was therefore a specific but not a very sensitive tumor marker. Its rate of staining of rhabdomyosarcomas is compared with the results in the literature. A great disparity is found and the reasons for this are discussed.

[Variability and inheritability of the "level of endogenous SH groups" trait in cell and clone populations of transplantable rat tumors]. / Izmenchivost' i nasleduemost' priznaka "uroven' éndogennykh SH-grupp" v populiatsiiakh kletok i klonov transplantiruemykh opukholei u krys

Heterogeneity of cell and clone populations in various histogenesis of rat tumours has been studied by the content of the endogenic SH-groups. The distribution of the ovary tumour cells and their clone lines, as well as lung clones of the sublines of rat rhabdomyosarcoma RA-2 as to the content of endogenic SH-groups is of persistent and monopeak character. Modal classes are well expressed, in several clone lines variability of the cell composition is higher than in the initial population. In this case the distribution of cells as to the SH-group content differs from the normal (asymmetrically). The level of SH-groups in the RA-2 rat subclone in 71 lung clones positively correlates with the level in hypodermic transplants. So, the heterogeneity of the clone populations as to the amount of SH-groups depends on both the genetic interclonal differences and fluctuations of the environmental factors.

Lectin histochemistry of experimental murine rhabdomyosarcomas.

Methylcholanthrene-induced murine rhabdomyosarcomas and skeletal muscle of 10 and 18 d old murine embryos were investigated by lectin histochemistry (WGA, RCA-I, LCA, Con-A, PSA, UEA-I, PNA) and by immunohistochemistry (vimentin, desmin, myoglobulin). In rhabdomyosarcomas as well as in the developing skeletal muscle a clear trend was visible. A decrease of vimentin positivity and an increase of desmin positivity were associated with a diminution of binding sites for WGA, RCA, and LCA. No binding moieties for these lectin could be demonstrated in myoglobin positive normal and neoplastic rhabdomyomatous cells at all. The homologous expression or absence of markers reflected the cellular variability in rhabdomyosarcomas and may be explained as a phenomenon of different tumor cell maturation. The results show that rhabdomyosarcomatous cells are imitating the normal skeletal muscle development.

[Protein S-100 in spontaneous soft tissue and peripheral nerve neoplasms in rats]. / Belok S-100 v spontannykh opukholiakh miagkikh tkanei i perifericheskikh nervov krys.

16 spontaneous tumors of the peripheral nerves and 18 spontaneous tumors of mesenchymal origin in BDVI rats were studied by peroxidase-antiperoxidase method using anti-serum (DAKOPATT) against protein S-100. The majority of spontaneous peripheral nerve tumors were of cystic histological structure identical to that of cystic neurinomas induced in rats by ethylnitrosourea and almost all of these tumors were S-100 protein positive. The incidence of spontaneous neurinomas in BDVI rats was in some experiments as high as 5%. All tumors of mesenchymal origin (except one lipoma) were S-100 protein negative: 2 fibromas, 6 fibrosarcomas, 3 malignant fibrous histiocytomas, one rhabdomyosarcoma and one hemangioendothelioma. S-100 protein is found, as in human pathology, useful for distinguishing tumors of schwann cell and mesenchymal origin in rats.