Cerebral granular cell tumor: immunohistochemical and electron microscopic study.

A rare intracerebral granular cell tumor (GCT) was studied by immunocytochemical and ultrastructural methods. The tumor was composed of two cell types--filament-rich and granular cells. Granular cells contained PAS-positive, diastase-resistant granules that ultrastructurally corresponded to autophagic cytosegresomes. Glial fibrillary acidic protein, the intermediate filament protein specific for astrocytes, was demonstrated in the filament-rich and, to a lesser extent, in the granular cells. Unlike noncerebral GCT, neither S-100 protein nor vimentin was detected in the tumor cells. On the other hand, both cerebral and noncerebral GCT were labeled immunocytochemically with peanut lectin (Arachis hypogaea). The results suggest that cerebral GCT share some features with noncerebral GCT, but differ in other respects. They further suggest that GCT may be derived from different cell types depending on the tissue of origin, and that cerebral GCT may be derived from astrocytes.

Myofibroblastoma of the breast. Sixteen cases of a distinctive benign mesenchymal tumor.

The clinical and pathologic findings of 16 examples of a distinctive stromal tumor of the breast designated as "myofibroblastoma" are reported. Eleven of the 16 patients were men, and the average age at presentation was 63 years. Fourteen were treated by local excision and two by simple mastectomy. None of the lesions recurred or metastasized. The tumors were grossly nodular and well-demarcated from the surrounding mammary tissue. Ducts and lobules were not engulfed by the neoplasm. Microscopically, the lesions were formed by uniform, slender, bipolar spindle cells haphazardly arranged in fascicular clusters separated by broad bands of hyalinized collagen. Ultrastructural examination of four lesions identified a predominance of myofibroblasts. Immunoreactivity for S-100 protein and cytokeratin was absent in the 10 tumors examined, but desmin immunoreactivity was focally present in three lesions. The differential diagnosis of myofibroblastoma includes reactive processes and benign neoplasms such as nodular and proliferative fascititis, fibromatosis, spindle-cell lipoma, neurofibroma, neurilemmoma, and leiomyoma. Malignant neoplasms such as stromal sarcoma, malignant fibrous histiocytoma, and spindle-cell or metaplastic carcinoma should not be confused with a myofibroblastoma. The clinical significance of this entity lies primarily in its recognition as a distinctive benign neoplasm.

Localization of myoglobin in normal and neoplastic human skeletal muscle cells using an immunoperoxidase method.

Using an immunoperoxidase method, myoglobin is localized in the cytoplasm of normal and neoplastic human skeletal muscle. The staining intensity is variable in individual cells. This can be explained by the variable concentration of myoglobin in the different fiber types of normal muscle or the different degree of differentiation in neoplastic muscle cells, respectively. A potential application of this method in tumor pathology is discussed in connection with myoglobin as a tissue-specific marker for skeletal muscle neoplasms.

The immunohistochemistry of gastrointestinal stromal tumors. Evidence supporting an origin from smooth muscle.

To study the histogenesis of gastrointestinal stromal tumors, 79 cases were evaluated for desmin (DES), vimentin (VIM), and S-100 protein immunoreactivity by the avidin-biotin immunoperoxidase procedure on paraffin-embedded, Bouin's-fixed tissue sections. All tumors showed weak vimentin positivity. Trapped non-neoplastic smooth muscle and nerve twigs were often noted, particularly at the tumor periphery. Significant tumor S-100 positivity was not identified in our series. Similarly, glial fibrillary acidic protein (GFAP) immunoreactivity (performed in 11 desmin-negative tumors) was not detected within either gastrointestinal stromal tumors or enteric glial cells. Fifty-three percent (53%) of all gastrointestinal stromal tumors (GIST) displayed positive tumor cell desmin immunoreactivity. All 10 esophageal and all four colorectal tumors were diffusely desmin positive and unequivocal smooth muscle lesions. In contrast, only 17 of 37 (46%) benign and six of nine (67%) malignant gastric tumors were desmin positive. Similarly, four of 10 (40%) benign and one of nine (11%) malignant small-bowel tumors expressed desmin. Several gastric neoplasms with prominent nuclear palisading resembling schwannian Antoni A regions were nonetheless desmin positive. Epithelioid gastric tumors were more frequently desmin positive than nonepithelioid tumors; however, this positivity did not attain statistical significance. Two gastrointestinal stromal tumors that were desmin negative in paraffin-embedded material had detectable antigen in frozen sections. Gastric and small-bowel tumors measuring less than 3 cm were significantly more often desmin positive than those 3 cm or greater. We conclude that the method of fixation, tissue preparation, and immunostaining may significantly affect the expression of desmin. Although the histogenesis of gastrointestinal stromal tumors remains controversial, most of these tumors show evidence of smooth muscle differentiation.

An immunoperoxidase investigation of S-100 protein in granular cell myoblastomas: evidence for Schwann cell derivation.

Five cases of granular cell myoblastoma have been studied for detection of the neuroectodermal protein S-100. Immunoperoxidase staining on paraffin sections, using an antibody raised against calf brain S-100 protein, was utilized to demonstrate positive cytoplasmic and nuclear reactivity in all cases. Negative staining in adjacent muscle and connective tissue elements was contrasted to in situ control staining of Schwann cells in peripheral nerves and staining of Langerhans cells and melanocytes in overlying stratified epithelia. These observations are interpreted as support for possible Schwann cell origin of granular cell myoblastomas.

Immunohistochemical study of granular cell tumour.

Immunoperoxidase studies were performed on 8 granular cell tumours using various intermediate filament proteins, as well as lysozyme, S-100 protein, and lectins. All the lesions gave negative results to cytokeratin, vimentin, desmin, myoglobin, neurofilament protein, glial fibrillary acidic protein and lysozyme. One was positive for alpha-1-antitrypsin and alpha-1-antichymotrypsin. S-100 protein and lectins (Concanavalin ensiformis and Triticum vulgaris) were uniformly positive in all the lesions. S-100 protein positivity would indicate that granular cell tumours are of neural or neuroectodermal origin, although the cell type involved is not clear. There is no obvious explanation for the lectin-binding properties of granular tumour cells. It is hoped that further studies will evaluate the usefulness of lectin histochemistry in defining the nature of granular cell tumours.

Immunohistochemical observation of S-100 protein and neuron specific enolase in the tumour cells of granular cell tumour.

An immunohistochemical technique for the detection of S-100 protein, neuron specific enolase (NSE), carcinoembryonic antigen (CEA) and muramidase (lysozyme) was applied to a case of the granular cell tumour. S-100 protein was detected both in the nuclei and cytoplasma of the granular cells, and NSE was weakly positive in their cytoplasms. CEA and lysozyme were negative in the tumour cells. Our results supports the concept that granular cell tumours are derived from Schwann cells.

[Actomyosin preparations obtained from a skeletal muscle tumor of low differentiation using the traditional methods of muscle biochemistry]. / Aktomiozinovye preparaty, poluchennye iz nizkodifferentsirovannoi skeletno-myshechnoi opukholi s pomoshch'iu traditsionnykh metodov myshechnoi biokhimii.

Tumor actomysion preparations isolated by three different extracting solutions are very similar in composition. A characteristic feature of the preparations obtained is a very rapid presumably proteolytic degradation of their components. It is shown that the major polypeptides of freshly prepared samples are not products of proteolysis. The major protein components of these preparations are identified.

[Isolation of actomyosin from a skeletal muscle tumor of low differentiation]. / Vydelenie aktomiozina iz nizkodifferentsirovannoi skeletnomyshechnoi opukholi.

A method of actomyosin (AM) isolation from low-differentiated rhabdomyocarcoma (LD RMS) has been worked out. The preparations obtained are sufficiently pure to be used for determination of the composition and some properties of major contractile proteins. Data on the composition of AM preparations isolated from LD RMS by traditional muscular biochemical methods (Matveyev, 1984) and morphological peculiarities of LD RMS cells, which help to distinguish them from definitive skeletal muscle cells and to relate them to non-muscle and low-differentiated muscle cells (mitotic myoblasts), served the main prerequisite to developing the method. Thus, this method may be regarded as a rational basis for isolation of non-muscle and embryonic contractile proteins, but it can be used, probably, for such purposes without special any adjustment to non-muscle or embryonic cells. The cytoplasmic localization has been shown for the tumor myosin.

[Granular cell tumor. Unusual location]. / Tumor de células granulares. Localización unusual.

The myoblastoma or Abrikossoff' tumor is a kind of harmless tumor that concerns to adult people and whose origin remains being a controversy. We report a new case of Abrikossoff' tumor with a unusual localization and emphasizing on its histogenesis.

[Immunohistochemical localization of S-100 protein in granular cell myoblastoma]. / Localización inmunohistoquímica de la proteína S-100 en el mioblastoma de células granulares.

Three cases of granular cell myoblastoma have been studied in order to determine the presence and distribution of the S-100 specific protein in the neoplastic cells, using immunocytochemical staining techniques, through the modified avidin-biotin method. Positive immunostaining was observed in the three cases studied. The comparative study of various control cases histogenetically originating from neuroectoderm (melanoma) and specifically from Schwann cells, as also the presence of strongly positive staining in Schwann cells of peripheral nerve fibres situated inside and outside the tumor, support the concept of the neurogenic origin of this interesting tumor.

Granular-cell tumours of the skin do not express carcino-embryonic antigen.

Granular-cell tumour (GCT) of the skin is an uncommon tumour of disputed histogenesis, that has been subjected to several immunohistochemical studies. The controversy existing in the literature concerning the expression of carcinoembryonic antigen (CEA) by GCT prompted us to study a series of 17 cases of cutaneous GCT by using an avidin-biotin-immunoperoxidase technique on routinely-processed tissue sections. No CEA activity was detected in any of the tumours screened. The reasons for this controversy are discussed.

Malignant granular cell tumor: immunocytochemical and ultrastructural observations.

Malignant granular cell tumor is an exceedingly rare tumor and only a few cases are documented in the literature. We report a malignant granular cell tumor of the subcutaneous tissue of the thigh in a 59-year-old man, and discuss the ultrastructural and immunocytochemical findings and their diagnostic value.

[Cerebral granular cell tumor in the rat after intraperitoneal application of aflatoxin b1 during pregnancy (author's transl)]. / Granularzelltumor des ZNS bei der Rate nach intraperitonealer Applikation von Aflatoxin B1 während der Tragezeit

On a rat, which has spontaneous died 12 months after 4 times i.p. application of aflatoxin during pregnancy, there has been found a frontal tumor barely of the size of a pepper-corn which came out from the leptomeninx. A comparison to the Abrikossoff tumor concerning the light- and electron-microscope as well as the nucleic-acid concentration is justified. The protein content of the granula of the tumor cells is higher than the values known in the granular-cell myoblastoma of man.

Myoglobin content of granular cell tumor of the tongue. An immunoperoxidase study.

Myoglobin is a protein with a molecular weight of 16,900 daltons that is normally found in adult and fetal striated and cardiac muscle cells. Its synthesis relates to the total ATP requirements of the muscle cell. The histogenesis of the granular cell tumor is controversial, but an origin from striated muscle has been postulated. Seven cases of tongue GCT were evaluated for the presence of myoglobin using the unlabeled antibody (PAP) technique. Normal human striated muscle was used for both positive and negative controls. None of the tumors showed positive staining of the granular cells. Positive controls showed specificity of staining for skeletal muscle. The negative controls did not stain. Granular cell tumors of the tongue do not appear to contain myoglobin. This suggests that either the GCT is not of muscle origin or that, if it is, there may be a metabolic change in the granular cells so that myoglobin is not synthesized. It may be possible that a change in the antigenic determinant has occurred.

Granular cell tumors contain myelin-associated glycoprotein. An immunohistochemical study using Leu 7 monoclonal antibody.

An immunohistochemical staining procedure using Leu 7 (HNK-1) monoclonal antibody was used to study the distribution of myelin-associated glycoprotein in granular cell tumours. Positive reactions were noted in 10 of the 13 tumours investigated. This observation supports the concept that granular cell tumours are of Schwann cell origin.

Fast and slow myosins as specific markers of muscle: an immunocytochemical study.

Slow and fast myosins are specific markers of skeletal muscle. The specificity of anti-fast and anti-slow myosin antisera been verified on frozen and paraffin embedded tissues. The optimal fixative useful for routine histopathological purposes has been investigated. It is suggested that these two antisera can be used in the diagnosis of rhabdomyoblastic tumours substituting for or complementary to myoglobin, a well known marker of striated muscle.

Minute esophageal granular cell tumor: a case report with immunohistochemical and ultrastructural examination.

A small granular cell tumor (GCT) of the esophagus, which developed in a 44-year-old Japanese man and was removed by endoscopic polypectomy, is presented. Histopathologically, the tumor, located in the submucosa, was composed of uniform neoplastic cells with nuclei and abundant round or oval cytoplasm containing eosinophilic granules. An immunohistochemical examination showed positive reactions with S-100 protein, especially the beta subunit, and neuron specific enolase in the neoplastic cells. Electron microscopic observation revealed abundant electron-dense or light granules and myelin-like structures in the cytoplasm. These findings support the concept that esophageal GCT is derived from Schwann cells.

Granular cell tumor of the orbit.

An 18-year-old woman had a 3-month history of increasing proptosis and visual loss secondary to an inferior orbital mass. Surgical exploration revealed an encapsulated mass in the orbit. After this mass was excised good vision was restored. The diagnosis of granular cell tumor was made as a result of various microscopic studies. The location of the tumor within the orbit is unusual and its histologic origin is uncertain. Immunohistochemistry by peroxidase-antiperoxidase method revealed that this tumor had S-100-protein-positive cells and negative results for lysozyme and alpha-1-antitrypsin. This fact suggests that the origin of the granular cell tumor may be due to the Schwann cell.