1/67. Low-grade malignant perineurioma of the paravertebral column, transforming into a high-grade malignancy.A demarcated 6 x 5 cm right paravertebral tumor at the level of T6 in a 39-year-old male was removed surgically. Histologically, the tumor consisted of monomorphous benign-looking, low-cellular spindle cells embedded in desmoplastic stroma. Ten years later, the tumor recurred locally with metastasis to systemic organs, including the occipital skin. Malignancy was histologically evident by the increased cellularity, cellular atypia and mitotic activity. The patient died of respiratory failure at the age of 49. Retrospectively reviewed, the primary lesion was low-grade fibrosarcoma-like spindle cell tumor, with secondary transformation into a highly malignant form. The differential diagnoses included sclerosing epithelioid fibrosarcoma, low-grade fibromyxoid sarcoma and malignant peripheral nerve sheath tumor. Immunohistochemically, the spindle cells in the primary and recurrent tumors consistently expressed epithelial membrane antigen, vimentin, type 4 collagen and laminin. The tumor cells in the present case showed a differentiation toward perineurial cells, which are normally positive for these immunohistochemical markers. Hence, the appropriate diagnostic term should be 'malignant perineurioma', a subtype of malignant peripheral nerve sheath tumor.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/67. Benign glandular peripheral nerve sheath tumor of the seventh and eighth cranial nerve complex.A unique, deep-seated, benign, glandular peripheral nerve sheath tumor (PNST) of the cerebellopontine angle is described. The tumor arose from the seventh and eighth cranial nerve complex in a 15-year-old boy without neurofibromatosis. Histologically, benign glands were embedded in a bland spindle cell stroma. The epithelial cells were immunoreactive for CAM 5.2, and focally for chromogranin. The spindle cells were positive for S100P. The benign glandular PNST unassociated with neurofibromatosis is a controversial entity. The superficial location of most reported cases has made it difficult to exclude entrapped adnexae as a source for the glands. This tumor was separate from the internal auditory meatus on MRI scan, the most likely source of entrapped glands at this site. This case is the first report of a deep-seated, benign, glandular peripheral nerve sheath tumor. It suggests that glandular differentiation in PNSTs, while unusual, is not synonymous with neurofibromatosis or malignancy.- - - - - - - - - - ranking = 0.66666666666667keywords = spindle cell, spindle (Clic here for more details about this article) |
3/67. Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study.A rare example of malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. immunohistochemistry would be useful as an ancillary technique in such a setting.- - - - - - - - - - ranking = 1.0837682465995keywords = spindle cell, spindle (Clic here for more details about this article) |
4/67. Malignant peripheral nerve sheath tumor with a t(X;18).We describe an ankle tumor arising in a 16-year-old girl. The tumor demonstrated histology typical of a malignant peripheral nerve sheath tumor (MPNST), but exhibited a variant form of the (X;18) translocation associated with synovial sarcoma. Immunohistochemical stains were positive for vimentin, CD57, collagen type iv, and Bcl-2. Routine and molecular cytogenetic studies showed an unbalanced 3-way chromosomal translocation that involved chromosomes X, 18, and 1. Electron microscopic findings were noncontributory. This unusual tumor raises the following questions and possibilities: (1) As the t(X;18) suggests, could this tumor be a monophasic synovial sarcoma with the histologic features of an MPNST? (2) Or, as the histology suggests, is this tumor an MPNST that has a t(X;18)? (3) Finally, could MPNST histology, a t(X;18), and no defining immunohistochemical or electron microscopic features represent an as yet unrecognized part of a spectrum that spans from synovial sarcoma to MPNST or other spindle cell tumors?- - - - - - - - - - ranking = 0.33333333333333keywords = spindle cell, spindle (Clic here for more details about this article) |
5/67. Intraneural perineurioma involving the median nerve.Intraneural perineurioma is a rare clinical entity, which tends to affect major nerve trunks in the upper extremities. On light microscopy, numerous pseudo-onion-bulb structures having a central clear area are surrounded by concentric layers of eosinophilic elongate cells having spindled nuclei. immunohistochemistry of concentric cells stains positive for epithelial membrane antigen but negative for S100 protein. Because of the small number of cases, no consensus has been made on proper treatment of this entity. Although none of the patients who have had excision of tumor with nerve grafting have had sensory nerve recovery, we believe each patient should be individualized until more data are available regarding this tumor.- - - - - - - - - - ranking = 0.083768246599489keywords = spindle (Clic here for more details about this article) |
6/67. Glandular malignant peripheral nerve sheath tumor: an unusual case showing histologically malignant glands.In this report, we describe a highly unusual case of glandular malignant peripheral nerve sheath tumor presenting as a neck mass in a previously healthy 29-year-old man. Grossly, the tumor was found to arise from a swollen peripheral nerve trunk. The tumor was largely composed of spindle cells that demonstrated marked nuclear pleomorphism and numerous abnormal mitotic figures. In addition, histologically malignant glandular structures lined by simple nonciliated columnar cells with goblet cells were found clustered in the center of the tumor. Examination of the swollen peripheral nerve trunk revealed the presence of a plexiform neurofibroma. The spindle cells were positive for S100. The glands were negative for S100 but positive for keratin, epithelial membrane antigen, and neuroendocrine markers (somatostatin, chromogranin, Leu-7, and calcitonin). This patient was subsequently diagnosed as having von Recklinghausen disease and died of tumor metastasis to the lungs 34 months after the presentation. To our knowledge, only 3 similar cases have been previously described in the literature.- - - - - - - - - - ranking = 0.66666666666667keywords = spindle cell, spindle (Clic here for more details about this article) |
7/67. Primary extracranial meningioma of the foot: a case report.We present a rare case of primary extracranial meningioma in a 36-year-old man, who had a solitary multinodular mass located in the plantar muscle of the foot. The histology of specimens from simple excision was typical of meningioma, showing bland spindle cell proliferation with a whorl pattern. Immunohistochemical analysis demonstrated that the tumor cells showed diffuse and strong positivity for epithelial membrane antigen as well as moderate reactivity for cytokeratin and vimentin. Ultrastructurally, the tumor cells were characterized by thin bipolar cytoplasmic processes and joined by multiple small desmosomes. There were frequent pinocytotic vesicles and a distinct external lamina on the cell surface. These findings suggest that this primary ectopic meningioma, arising in the soft tissue, may have been derived from perineurial cells of the peripheral nerve, but was morphologically distinguishable from perineurioma. Primary extracranial meningioma should be included in the differential diagnosis of soft-tissue spindle cell tumors, especially those of peripheral nerve origin.- - - - - - - - - - ranking = 0.66666666666667keywords = spindle cell, spindle (Clic here for more details about this article) |
8/67. Fine-needle aspiration cytology and core biopsy of malignant peripheral nerve sheath tumor of the uterus: a case report.Malignant peripheral nerve sheath tumor (MPNST) is an uncommon mesenchymal neoplasm of neural origin. MPNST arising in the uterus is extremely rare. Its histologic appearance on this anatomical location has been only rarely reported. A 62-yr-old woman with a previous history of partial hysterectomy presented with a large pelvic mass in the uterine stump. Fine-needle aspiration (FNA) and core biopsy were obtained under ultrasonographic guidance, and the diagnosis of MPNST was established. The cytologic and histologic findings were consistent with a spindle-cell neoplasm suggestive of MPNST. The tumor cells were focally positive for S-100 protein immunostain, thus providing further support for the neoplasm's nerve sheath differentiation. The patient had no history of von Recklinghausen's disease. Resection of the mass confirmed the diagnosis of MPNST. To our knowledge, the FNA cytology of MPNST in this unusual location has not been previously reported. FNA cytology, along with core biopsy and immunochemistry, is a reliable tool in the diagnosis of MPNST.- - - - - - - - - - ranking = 0.083768246599489keywords = spindle (Clic here for more details about this article) |
9/67. Non-neoplastic glandular structures in a benign peripheral nerve sheath tumor.It is a recognized fact that glandular structures sometimes occur in peripheral nerve sheath tumors (PNST). Reports indicate that epithelial potential could be expressed in malignant PNST, while the glands in most benign PNST could be trapped skin adnexa. We present a case of spindle cell tumor with glandular structures. The patient was a 55-year-old man who had a subcutaneous tumor excised. The spindle cell tumor had histological characteristics of neurofibroma. The glandular structures had a pattern of immunohistochemical staining that was similar to that of the secretory coils and excretory ducts of normal eccrine glands. Therefore, the glands were thought to be naturally existing eccrine glands. The glands were completely enclosed within the tumor and not connected to one another; a cluster formation was not observed. The upper portion of tumor included some glands of skin adnexa. The spindle cell tumor may have originated from the nerves distributed around the skin adnexa, and grown to the subcutaneous tissue. The glands may have been left behind rather than have been trapped in the tumor.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
10/67. Sclerosing perineuriomas affecting bilateral hands.Sclerosing perineurioma is a rare, recently described variant of perineurioma that tends to affect the fingers and palms of adolescents or young adults. The process typically presents as a painless, well-circumscribed, unencapsulated nodule involving subcutis or reticular dermis. To our knowledge, all of the previously reported sclerosing perineuriomas were solitary. Hence, we report a 16-year-old boy, without stigmata of neurofibromatosis, who developed one sclerosing perineurioma in the right palm and another on the left index finger. Microscopically, tumours at both sites revealed small epithelioid and plump spindle cells with trabecular, whorled, or Indian file growth pattern enmeshed within extensively hyalinizing stroma. Immunohistochemically, the tumour cells showed strong reactivity for EMA but negative staining for S-100 and neurofilament. Ultrastructually, the tumour cells in both lesions exhibited features of perineurial cells, including discontinuous external basal lamina, occasional pinocytotic vesicles, and encirclement of abundant collagen fibrils by the interdigitating cytoplasmic processes. This case confirms the fact that sclerosing perineurioma is not always solitary.- - - - - - - - - - ranking = 0.33333333333333keywords = spindle cell, spindle (Clic here for more details about this article) |
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