1/18. Unusually differentiating immature nerve sheath myxoma in association with dermal melanocytosis.A 44-year-old woman presented with a slightly elevated, erythematous lesion, with partially blue-black areas. The nonpigmented area histologically showed a "dissecting" fascicular growth pattern, similar to one of the patterns seen in the cellular type of nerve sheath myxoma. The clinically pigmented part of the lesion consisted of diffusely infiltrating, broad and poorly delineated fascicles often showing nerve sheath differentiation, embedded in a highly myxomatous stroma. No part of the lesion showed the plexiform pattern typical of the classic type of nerve sheath myxoma; rather, the lesion had some common features of neurofibroma, and also was characteristically associated with a considerable number of scattered dermal melanocytes. However, based on the fascicular histologic pattern showing nerve sheath differentiation within mucinous matrix, S-100 protein-negative immunophenotype, and electron microscopic features, we considered the whole lesion in the present case to be an entity within the spectrum of nerve sheath myxoma, either mixed-type nerve sheath myxoma or unusually differentiating immature nerve sheath myxoma, except for the associated dermal melanocytosis. Because of the intimate association of the dermal melanocytes with this nerve sheath myxoma with divergent differentiation, this lesion can also be considered as a distinctive type of benign neoplasm derived from pluripotent neural crest cells.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/18. neurothekeoma palpebrae: a rare nerve sheath tumor arising in the eyelid.PURPOSE: To report a case of an eyelid neurothekeoma, a rare peripheral nerve sheath tumor. methods: Case report. RESULTS: An excisional biopsy, performed on a lesion removed from the upper eyelid of a 76-year-old woman, revealed the clinical and histopathologic features of a neurothekeoma, a tumor consisting of multiple collections of spindle cells in a myxomatous background. Immunohistochemical characterization showed positivity for NK1/C3, neuron-specific enolase, and alcian blue. CONCLUSION: neurothekeoma palpebrae should be considered in the differential diagnosis of solitary nodules of the eyelids.- - - - - - - - - - ranking = 0.41666666666667keywords = nerve (Clic here for more details about this article) |
3/18. Nerve sheath myxoma (neurothekeoma) in the tongue of a newborn.Nerve sheath myxoma is a benign peripheral nerve sheath tumor that rarely occurs in the oral cavity; experience with these lesions is therefore limited. The lesion described in this report appeared clinically as a gradually enlarging, painless growth arising on the tongue of a newborn girl. Microscopically, the lesion was characterized by nodules of spindle-shaped cells with abundant myxoid stroma. Immunohistochemical studies were consistent with a nerve sheath neoplasm.- - - - - - - - - - ranking = 0.16666666666667keywords = nerve (Clic here for more details about this article) |
4/18. Intraoral myxoid nerve sheath tumour.A case of an intraoral myxoid nerve sheath tumour of the dorsum of the tongue in a 73-year-old Caucasian male is reported. This case describes the oldest patient with this pathology to date. Immunoperoxidase staining for neuron-specific enolase (NSE) and epithelial membrane antigen (EMA) expression demonstrated the perineural origin of the lesion.- - - - - - - - - - ranking = 0.41666666666667keywords = nerve (Clic here for more details about this article) |
5/18. Cellular neurothekeoma of the oral mucosa.Cellular neurothekeoma is an unusual benign neoplasm which, despite its name, is of uncertain origin. This report describes a cellular neurothekeoma of the cheek mucosa, the first at this site. The tumour presented in a 29-year-old man as a discrete mucosal thickening. histology showed a generally well circumscribed, but unencapsulated, solid tumour which replaced the entire lamina propria and permeated between minor salivary glands and bundles of striated muscle in the submucosa. There was a sub-epithelial Grenz zone. The tumour was composed of nodules of pale, epithelioid cells separated by fascicles of spindle cells, with smaller strands and nests superficially. The nuclei were vesicular and, though mainly bland, occasionally atypical. The stroma was moderately infiltrated by mixed chronic inflammatory cells. Prominent nerves and blood vessels were seen at the periphery of the lesion, and neoplastic cells were noted within intact striated muscle fascicles. With immunohistochemistry, all the neoplastic cells strongly expressed NKI/C3, synaptophysin, neurone-specific enolase and vimentin, some expressed smooth muscle actin and PGP 9.5, but all were negative for S100, factor xiiia, CD34, CD56, CD57, CD68, chromogranin a, desmin, epithelial membrane antigen and von willebrand factor. The origin of the lesion is thus speculative. It was, however, completely excised and in 12 months there has been no recurrence.- - - - - - - - - - ranking = 0.083333333333333keywords = nerve (Clic here for more details about this article) |
6/18. Intracranial neurothekeoma--a rare parenchymal nerve sheath myxoma of the middle cranial fossa.Neurothekeomas are rare, benign nerve sheath tumors, usually arising from cutaneous nerves in the head and neck region. So far, only 4 cases of the intracranial counterpart have been reported and these were located in the posterior fossa, sellar and parasellar region. We report here the first case of neurothekeoma located deep inside the brain parenchyma. Histologically, the tumor had lobular appearance with bland morphology in spite of cellular pleomorphism, myxoid background and variable S-100 positivity, characteristics of neurothekeomas. The schwannian origin was further confirmed ultrastructurally by demonstrating basal lamina and Luse bodies. Because of its benign nature, the lesion does not need postoperative radiotherapy. Histogenesis of neurothekeoma arising in the parenchyma remains enigmatic. The probable cell of origin could be the Schwann cell or perineurial cell of the nerve twigs around the blood vessels or by extreme differentiation of the precursor cell resting in a suitable microenvironment to the schwannian phenotype.- - - - - - - - - - ranking = 0.58333333333333keywords = nerve (Clic here for more details about this article) |
7/18. Cytologic findings of myxoid neurothekeoma: case report based on fine-needle aspiration cytology, immunohistochemistry, and correlating histopathology.Myxoid neurothekeomas (nerve sheath myxomas) are rare benign cutaneous neoplasms that may morphologically mimic other myxoid neoplasms of skin and soft tissue. The cytologic and histopathologic features of this lesion may resemble various myxoid sarcomas, chordoma, myxoid neurofibroma, dermal cutaneous mucinosis, and cutaneous myxoma as well as other myxoid or chondroid neoplasms. In this study, a myxoid neurothekeoma was analyzed using multiple techniques. We found that myxoid neurothekeomas reveal a nonspecific pattern by fine-needle aspiration, including stellate cells embedded within an abundant metachromatic myxoid stromal matrix. These are cytologic features shared by various other subcutaneous neoplasms and thus may not be helpful in forming a definitive diagnosis. Histopathologically, the tumor is composed of nodules of myxoid stroma containing interspersed bland spindled and stellate cells. Immunohistochemical studies show tumor cell positivity for S-100 protein and vimentin, a profile shared by other neoplasms with similar cytologic features and therefore of little diagnostic value. The histologic and cytologic differential of subcutaneous and soft tissue myxomatous lesions is broad and, therefore, is of unique value to the cytopathologist to consider myxoid neurothekeomas among the differential of other myxomatous neoplasms.- - - - - - - - - - ranking = 0.083333333333333keywords = nerve (Clic here for more details about this article) |
8/18. Atypical cellular neurothekeoma.BACKGROUND: neurothekeoma is a distinctive neoplasm that in the past was often lumped into the broad category of benign peripheral nerve sheath tumors. Atypical cellular neurothekeoma is a rare variant of this neoplasm. This atypical variant is characterized by features that can include the following: large sizes (up to 6 cm), deep penetration extending into skeletal muscle and/or subcutaneous fat, diffusely infiltrative borders, vascular invasion, high mitotic rate, and marked cytologic pleomorphism. methods: In this report, we describe the clinical, histopathologic, and immunohistochemical features of a case of atypical cellular neurothekeoma in a 34-year-old woman. RESULTS: This neoplasm demonstrated both the cellular subtype and intermediate subtype. In the cellular area, cells demonstrated rounded or ovoid nucleus with abundant cytoplasm. Mitotic activity ranged from 8 to 12 per 10 high-powered fields, and few individual cell necroses were present. In the intermediate area, cells were arranged as smaller nests with admixed abundant mucin. Mitotic activity ranged from 1 to 2 per 10 high-powered fields. These cells were negative for S100, epithelial membrane antigen, and smooth muscle actin. CONCLUSION: Dermatologists should be aware of the features of atypical cellular neurothekeoma. Although the atypical features raise concern about the malignant potential of this lesion, previous cases show that complete surgical excision of these lesions is curative.- - - - - - - - - - ranking = 0.083333333333333keywords = nerve (Clic here for more details about this article) |
9/18. neurothekeoma: report of a case in an infant and review of the literature.Neurothekeomas (nerve sheath myxomas) are uncommon benign tumors of nerve sheath origin. We describe an infant with a neurothekeoma and review the literature of neurothekeomas in children and adults. Neurothekeomas have been reported in 292 patients whose ages have ranged from 15 months to 84 years. They occur twice as often in women as in men. Neurothekeomas were most commonly located on the upper extremities and the head and neck. They also occurred on the trunk, the lower extremities, and mucosa. Histologic variants of neurothekeomas include classical, cellular, and mixed tumors. Surgical excision was the most common treatment. Recurrences were attributed to an incomplete excision; treatment of these tumors is by complete excision. Neurothekeomas should be included in the differential diagnosis of dermal nodules in infants and children.- - - - - - - - - - ranking = 0.16666666666667keywords = nerve (Clic here for more details about this article) |
10/18. neurothekeoma in the foot: a rare occurrence.neurothekeoma is a benign cutaneous neoplasm of nerve sheath origin. This seldom-seen entity is especially rare in the foot. We provide an overview of neurothekeoma and describe a patient with an occurrence in the foot that was effectively treated by complete excision of the mass.- - - - - - - - - - ranking = 0.083333333333333keywords = nerve (Clic here for more details about this article) |
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