RESUMEN

Neurofibromas are often clinically, as well as histologically, indistinguishable from completely neurotized melanocytic nevi. We tested the hypothesis that immunologic markers would differentiate the perineural fibroblasts and Schwann cells of neurofibromas from the neurotized cells of melanocytic origin. We examined eight partially neurotized acquired melanocytic nevi, three partially neurotized congenital melanocytic nevi, and five neurofibromas, with antibodies directed against S-100 protein, Leu-7(HNK-1), glial fibrillary acid protein (GFAP), and myelin-basic protein (MBP). A histologic diagnosis of neurofibroma was based on identification of a dermal proliferation of spindle-shaped cells with wavy nuclei, in a background of loose reticulated collagen. Neurotized nevi were diagnosed upon recognition of scattered nests of type A or B nevus cells, surrounded by basement membrane, present in the papillary dermis of lesions otherwise indistinguishable from neurofibromas. The congenital nevi were all large melanocytic nevi known to be present at birth. S-100 stained the majority of neoplastic cells in all neurofibromas, neurotized acquired nevi, and neurotized congenital nevi. Neurofibromas showed focal staining for Leu-7, GFAP, and MBP. In contrast, neurotized acquired and congenital nevi failed to express these markers. We believe that Leu-7, GFAP, and MBP may be helpful in differentiating neurofibromas from completely neurotized melanocytic nevi. The differences in the immunohistochemical profiles of neurofibromas and neurotized nevi support the concept that these neoplasms are histogenically distinct, despite their similar histologic appearance.

Asunto(s)

RESUMEN

We have examined the cytoplasmic distribution of actin and fibronectin in cultured neurofibroma cells (NF cells) derived from a patient with von Recklinghausen's disease by using phase contrast and indirect immunofluorescence microscopy. NF cells were larger in size and more dendritic in shape compared to normal human dermal fibroblasts. NF cells also showed abundant granular staining of actin and a decrease in the linear staining pattern of fibronectin. Furthermore, employing a colony-formation assay on the top of an agar-gel in the presence of fibroblast growth factor (FGF), normal fibroblasts showed a significant number of colonies, whereas NF cells did not demonstrate colony formation even after addition of FGF. These findings suggests that NF cells from patients with von Recklinghausen's disease may have different characteristics when compared with normal fibroblasts, and that NF cells are similar to transformed cells with regard to their actin and fibronectin distribution.

Asunto(s)

RESUMEN

Neurofibromas, schwannomas, and neurotized melanocytic nevi may closely resemble one another at the light microscopic level. We studied 10 neurofibromas, 10 schwannomas, and 10 partially neurotized melanocytic nevi immunohistochemically using an antibody directed against factor XIIIa to determine if this antibody might provide a useful method of differentiating these lesions. The cases were also stained with S100 protein. All of the neurofibromas stained intensely for factor XIIIa. The proportion of cells staining within the tumors varied from 30% to 70%. In contrast, none of the schwannomas and neurotized nevi studied demonstrated staining of tumor cells with this antibody. S100 protein was expressed by 100% of neurofibromas, schwannomas, and melanocytic nevi. Our findings suggest that factor XIIIa may provide a reliable and practical means of differentiating cutaneous neurofibromas from neurotized nevi and cutaneous schwannomas. Distinguishing between these different tumor types may be important in some clinical situations, particularly with respect to rendering a diagnosis of von Recklinghausen's neurofibromatosis. The differences in the immunohistochemical profiles of neurofibromas and neurotized nevi support the concept that these tumors are histogenetically distinct, despite their similar histologic appearances.

Asunto(s)

Asunto(s)

RESUMEN

Formalin-fixed, paraffin-embedded sections of 59 ultrastructurally confirmed nerve sheath tumors (NSTs) that included 27 benign schwannomas, five neurofibromas, and 27 malignant schwannomas were studied by the avidin-biotin-peroxidase complex method using antibodies directed against glial fibrillary acidic protein (GFAP), keratin, S-100 protein, vimentin, and desmin. GFAP was expressed by 33% of the benign schwannomas, 40% of the neurofibromas, and 7% of the malignant schwannomas. Keratin was expressed by 7% of the benign schwannomas and 4% of the malignant schwannomas. S-100 protein was expressed by 100% of the benign NSTs and by 40% of the malignant schwannomas. Vimentin was observed in 100% of the benign NSTs and in 85% of the malignant schwannomas. None of the cases stained for desmin. GFAP and cytokeratin expression could not be predicted on the basis of tumor light microscopy or ultrastructure. These findings are of practical importance in routine surgical pathology, particularly with respect to the differential diagnosis of gliomas located in the central nervous system and in immunohistochemical studies of peripherally located, poorly differentiated neoplasms.

Asunto(s)

RESUMEN

We examined the cellular distribution of lipocortin-1 (L-1), a major physiologic substrate for the epidermal growth factor receptor/kinase, in 122 central nervous system (CNS) and peripheral nervous system (PNS) neoplasms using the peroxidase-antiperoxidase technique with a polyclonal antibody specific for L-1. Extensive L-1 immunoreactivity was demonstrated in many CNS tumors; in 11 of 21 glioblastoma multiformes, in five of 12 anaplastic astrocytomas, and in five of 14 astrocytomas. Significant numbers of immunoreactive ependymocytes or astrocytes were also seen in six of 13 ependymomas. In contrast, no immunostaining was detected in the oligodendrocytes in any of ten oligodendrogliomas. PNS tumors, found in two of five malignant nerve sheath tumors, 13 of 15 schwannomas, 13 of 17 neurofibromas, and 14 of 15 traumatic neuromas, also contained considerable L-1 immunoreactivity in Schwann cells or mast cells. These findings raise the possibility that L-1 may participate in the proliferation or subsequent differentiation of neoplastic astrocytes, ependymocytes, and Schwann cells.

Asunto(s)

RESUMEN

Forty-two nevus cell nevi excised surgically from 40 patients were processed for primary culture. The characteristic features of cultured nevi were compared with those of neurofibroma reported previously. 1) Based on phase-microscopic findings, S-100 protein staining, and slow motion picture, most of the cultured macrophage-like cells or cells with dendrites were considered to be nevocytes. 2) The emigration of nevocytes was observed in 31 of the 42 nevus cultures (73%). Nevocytes classified histologically as the intradermal type with fatty degeneration and nevi obtained from the face and aged patients exhibited higher tendencies to ward emigration when they were cultured. 3) The cultured Schwann cells in neurofibroma and the nevus cell nevus, mainly c-type nevocytes, are both of neural crest origin. They were observed to have closely similar morphological and S-100 protein staining features.

Asunto(s)

RESUMEN

Immunoreactivity of glial fibrillary acidic protein (GFAP) in 38 schwannomas and 18 neurofibromas was evaluated and compared with the reactivity of vimentin, S-100 protein, and neurofilament protein. All cases were positive for vimentin and S-100 protein. GFAP was positively stained in the neoplastic cells of 15 of 38 schwannomas (38%) and in two of 18 neurofibromas (11%). The extensively stained GFAP-positive tumors tended to be deeply situated in the body. The GFAP-positive cells were usually spindle-shaped and appeared preferentially in the perivascular region of hyalinized, thick blood vessels.

Asunto(s)

RESUMEN

The collective expression of five antigens produced in immature or mature myelin-producing glia was evaluated in nerve sheath tumors and spindle cell sarcomas with histologic features of schwannomas. Myelin-associated glycoprotein (Leu-7), myelin basic-protein (MBP), S100-protein, and, in most cases, glial-fibrillary acidic-protein (GFAP) and HLA-DR/Ia (LN3) immunoreactivity were evaluated immunohistochemically using commercially available antibodies on 53 benign nerve sheath tumors and 12 sarcomas. Leu-7 immunoreactivity was detected by a monoclonal antibody in 12 of 16 schwannomas, 12 of 20 neurofibromas, and 17 of 17 traumatic neuromas. No Leu-7 positivity was seen in the sarcomas. Distinct heavy MBP immunoreactivity, assessed using polyclonal antibodies, was identified only in all 17 traumatic neuromas. Extensive S100-protein positivity was seen in 15 of 16 schwannomas, 17 of 20 neurofibromas, and 17 of 17 traumatic neuromas. Extensive LN3 immunoreactivity was seen in Schwann cells of 50% of the nerve sheath tumors analyzed; however, it was also present in associated interdigitating reticulum cells; GFAP immunoreactivity was not detected. These data suggest that Leu-7 is an important marker of Schwann cell neoplasms, although it is not superior to S100 protein. Moreover, combined immunohistochemical evaluation of potential Schwann cell markers including Leu-7, MBP, GFAP, and LN3 using commercially available antibodies offers no advantage over analysis of S100-protein immunoreactivity alone.

Asunto(s)

RESUMEN

We studied glial fibrillary acidic (GFA) protein immunoreactivity in 30 schwannomas, including two intracerebral examples, 26 neurofibromas and 12 neuromas using the immunoperoxidase method with a polyvalent antiserum (PVAS) and three well-characterized monoclonal antibody (MAb) preparations. Twelve of the schwannomas, including both intracerebral tumors, two of the neurofibromas and none of the neuromas immunostained with PVAS. Except for one schwannoma, all the PVAS-positive tumors were positive with two of the MAb preparations. While both of the intracerebral schwannomas were positive with the third MAb, none of the extracerebral tumors were. Our results suggest that: 1) human nerve sheath tumors contain cells having polypeptides that share epitopes with GFA protein, but 2) these polypeptides differ from astrocytic GFA protein by at least one epitope, and 3) the location of the tumors in relation to the central nervous system may influence GFA protein immunoreactivity.

Asunto(s)

RESUMEN

A case of solitary appendicular neurofibromatosis is presented. The neurogenous nature of the lesion was emphasized by the positive reaction for S-100 protein. Attention is directed towards the morphological differences between neurogenous hyperplasia, which is a reactive common place feature in the elderly, and the present example of neoplastic nerve growth, which produced a gigantic appendix. A review of the literature failed to disclose any previous case unassociated with von Recklinghausen's disease.

Asunto(s)

RESUMEN

A periurethral neurofibroma presenting as a midline perineal mass was removed in a three-year-old boy. An immunohistochemical study of S-100 protein distribution within the tumor tissue was performed.

Asunto(s)

Asunto(s)

RESUMEN

The intermediate filament complement of the spectrum of nerve sheath neoplasms including 12 typical benign schwannomas, 1 ancient schwannoma, 2 cellular schwannomas, 6 neurofibromas and 4 malignant schwannomas was investigated by immunofluorescence microscopy, two dimensional electrophoresis, and immunoblot analysis. Studies were performed on freshly frozen tumor tissue samples; a broad spectrum of antibodies against all classes of intermediate filaments was utilized. Samples were also studied by electron microscopy, and immunohistochemically for S-100 protein and desmoplakins. By immunofluorescence microscopy, all nerve sheath neoplasms revealed intense positivity for vimentin throughout the cytoplasm while 2 benign schwannomas displayed co-expression of vimentin and glial filament proteins. Two-dimensional gel electrophoresis and immunoblot analysis confirmed the presence of vimentin and showed that it was the predominant protein in all tumors. Electrophoretic analysis of the 2 benign schwannomas that immunostained for glial filament proteins confirmed the presence of this protein which was shown to comigrate with a known human control sample. Neither immunofluorescence microscopy nor biochemical analyses revealed cytokeratin polypeptides, neurofilament proteins, desmin, or desmoplakin in any of the tumors. We conclude that while vimentin is the predominant intermediate filament expressed by the entire spectrum of nerve sheath neoplasms, at least occasional benign schwannomas are capable of co-expressing glial filament proteins. It remains to be determined whether the subgroup of nerve sheath neoplasms that co-expresses vimentin and glial filament proteins is otherwise distinguishable from their more frequent counterparts that express vimentin exclusively.

Asunto(s)

RESUMEN

The histological and immunohistochemical features of 3 cases of cellular neurothekeomas of skin are presented. Based on the findings in these cases and comparisons made with others reported in the literature, it is proposed that neurothekeomas may be divided into two distinct types: the myxoid and cellular variants. The relationship between these variants and a related entity, the Pacinian neurofibroma, is discussed.

Asunto(s)

RESUMEN

Morphological characteristics of tactile-like corpuscles (tactoid bodies, pseudomeissnerian corpuscles) which are occasionally present in neurofibromas have already been detailed. However, there has yet been controversy on the cytogenesis of these lamellated structures. Probably, one of the most important problems is whether tactile-like corpuscles are composed of Schwann cells or of perineurial cells. In this study, seven cases of neurofibromas with tactile-like corpuscles were examined by rabbit or mouse polyclonal antisera to S-100 protein which could be regarded, at least in the peripheral nervous system, as a specific marker for Schwann cells. Since recent extensive studies have revealed that S-100 protein is a mixture of two predominant dimeric components with S-100 alpha and S-100 beta subunits, and the S-100 alpha subunit is absent from Schwann cells, tactile-like corpuscles were also examined by a mouse monoclonal antibody (ASA-1) specific for the S-100 alpha subunit. For immunohistochemical analysis, peripheral nerves, Meissner corpuscles and epidermal melanocytes were also examined in parallel. By the immunoperoxidase method using rabbit or mouse polyclonal antisera to S-100 protein, tactile-like corpuscles were intensely stained in sections from all seven cases. Both the flattened cell bodies and the eccentrically located nuclei of their constituent cells were stained. In the background neurofibroma tissue surrounding the tactile-like corpuscles, spindle-shaped cells were stained variably. In three of the seven cases, numerous melanin-containing cells which often surrounded the tactile-like corpuscles were also stained. In normal peripheral nerves, positive staining was confined to Schwann cells and their processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Asunto(s)

RESUMEN

The present study was undertaken to clarify the ploidy patterns of peripheral nerve sheath tumors by determining nuclear DNA content of the individual tumor cells using PI-DNA cytofluorometry (NIKON SPM-RF1-D), and to investigate the relation between the ploidy patterns and histopathological findings. Most of the solitary neurilemmomas and neurofibromas studied were found to be associated with euploid-polyploidization, almost without DNA synthetic cells. It was also shown that the number of polyploid cells increased in accordance with an increase in the frequency of cells having large, atypical nuclei in histological picture, regardless of the natures of cellular arrangements. Malignant schwannomas, however, were composed of many polyploid and aneuploid cells with an increase of DNA synthetic cells, indicating their active cell proliferation. Thus, the ploidy patterns of nerve sheath tumors were remarkably different between benign and malignant ones. Furthermore, a case of multiple schwannoma suspected to be a variant of von Recklinghausen's disease, showed euploid-polyploidization with many DNA synthetic cells, indicating a ploidy pattern intermediate between benign and malignant tumors. This tumor thus appears to be a premalignant tumor or in the early stages of malignancy.

Asunto(s)

RESUMEN

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.

Asunto(s)

RESUMEN

A rare case of solitary neurofibroma located in the esophagus is reported. A large (4.2 X 4.0 X 3.0 cm) submucosal tumor was surgically removed from the midportion of the esophagus of a 64-year-old woman. Light and electron microscopic examination, and immunohistochemistry of S-100 protein in the tumor tissue confirmed neurofibroma. The patient had no evidence of von Recklinghausen's neurofibromatosis. A review of literature failed to find other reports of solitary neurofibroma of the esophagus with reliable histological diagnosis.

Asunto(s)

RESUMEN

Two pelvic benign neural tumors, a neurofibroma and a neurilemmoma, were found to have high levels of cell nuclear estrogen receptors and both cytoplasmic and nuclear progestin receptors. A review of the literature reveals that neurogenic tumors occur predominantly in young women. This observation together with the recent findings of elevated sex steroid receptor proteins in meningiomas supports a hypothesis for the common hormonal dependence of neoplasms arising from the neural supporting tissues.

Asunto(s)