Characterization of glycoconjugates found in granular cell tumors, with special reference to keratan sulfate.

Nine granular cell tumors (GCTs) were studied using the immunoperoxidase technique with a mouse monoclonal antibody to keratan sulfate and a polyclonal antibody to S-100 protein. Various lectins and basic dye stains were also employed. Schwannomas benign and a malignant, a neurofibroma, a leiomyoma, two examples of nevus pigmentosus and a congenital epulis were similarly examined to compare the histochemical reactivities. Tumor cells of all the GCTs reacted intensely with the antibodies to keratan sulfate and S-100 protein. Peripheral nerve bundles and other neurogenic tumors showed stained for S-100 protein but not for keratan sulfate. Basic dye stain indicated the presence of sulfated glycoconjugates in GCTs. Lectin stains demonstrated that GCTs were rich in glycoconjugates but the reactivity patterns for 14 lectins differed between GCTs and normal tissue components. None of the lectins used in this study was specific for GCTs. These results indicate that GCTs contain abundant glycoconjugates and that the monoclonal antibody to keratan sulfate may be an immunohistochemical marker for GCT.

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.

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.

[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 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.

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.

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.

Intermediate filament proteins and actin isoforms as markers for soft tissue tumor differentiation and origin. I. Smooth muscle tumors.

A series of 3 benign and 10 malignant smooth muscle (SM) neoplasms and of 2 malignant fibrous histiocytomas was examined by light microscopy, transmission electron microscopy, two-dimensional gel electrophoresis (2D-GE) and indirect immunofluorescence, using polyclonal monospecific or monoclonal antibodies to desmin, vimentin, cytokeratin, alpha-SM and alpha-sarcomeric (alpha-SR) actins. Benign neoplasms displayed typical light-microscopic features of SM, whereas leiomyosarcomas demonstrated variations in their histologic pattern. In 6 sarcomas, light microscopy suggested a SM differentiation, whereas in the other 4, a predominant nondistinctive spindle-cell pattern was observed. By transmission electron microscopy, all 13 neoplasms showed the minimal essential features of SM differentiation. Immunofluorescence disclosed heterogeneity of cytoskeletal protein expression: 5 neoplasms (3 benign and 2 malignant well-differentiated) expressed desmin, vimentin, and alpha-SM-actin; 2 malignant neoplasms expressed desmin and vimentin; 1 malignant neoplasm expressed desmin, vimentin and alpha-SR actin; 1 malignant neoplasm expressed vimentin and alpha-SR actin; and 4 malignant neoplasms expressed vimentin alone. By 2D-GE, 3 benign and 4 malignant SM neoplasms expressed alpha, beta, and gamma actins, and the remaining expressed only beta and gamma actins. The presence of alpha-SM actin in all benign neoplasms and in 2 well-differentiated leiomyosarcomas suggests that this actin isoform reflects a high degree of cellular differentiation. In 2 leiomyosarcomas, alpha-SR actin was detected by immunofluorescence, which suggested a skeletal muscle differentiation of these neoplasms. This study supports the assumption that leiomyosarcomas represent a heterogeneous group of neoplasms and furnishes new criteria for their characterization.

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.

Granular cell tumor of the ascending colon: a case report.

A granular cell tumor (granular cell myoblastoma) of the ascending colon in a 48-year old male is reported. The tumor was detected by barium enema study as a sessile polyp, and colonofiberscopy revealed submucosal tumor. It was removed by endoscopic polypectomy. Macroscopic examination showed the characteristic features of granular cell tumor. The avidin-biotin-peroxidase complex (ABC) method for detection of S-100 protein demonstrated that the cytoplasm of tumor cells and the pleomorphic nuclei were strongly stained with anti-S-100 protein serum, which supports the concept of the Schwann cell origin of granular cell 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.

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.

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.

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.

[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.

The pattern of distribution of laminin in neurogenic tumors, granular cell tumors, and nevi of the oral mucosa.

Oral tumors of presumably neuroectodermal origin were stained with anti-laminin antibody by a double layered immunofluorescence technique. A marked positive staining for laminin was found in neurofibromas and neurilemmomas although the pattern of laminin distribution was slightly different. Accentuated staining was seen in Verocay bodies. In granular cell myoblastomas (GCM), small groups of tumor cells were encircled by laminin-positive material, whereas individual tumor cells were unstained. In nevi, diffusely spread nevus cells were surrounded by a rim of laminin, whereas when arranged in nests whole groups of cells were encircled by laminin as seen in the GCM. Ordinary oral fibromas included as controls were negative except for the expected positive staining of basement membranes normally occurring in the tissues. Immunohistochemical demonstration of laminin seems to be a valuable aid in differential diagnosis of soft tissue tumors and may provide useful information about the pathogenesis of various lesions.

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.