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 = neoplasm (Clic here for more details about this article) |
2/18. 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 = 1keywords = neoplasm (Clic here for more details about this article) |
3/18. 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 = 1keywords = neoplasm (Clic here for more details about this article) |
4/18. neurothekeoma of the paranasal sinuses in a 3-year-old boy.neurothekeoma is a benign soft tissue tumor commonly located on the skin. In this report, a 3-year-old boy presented with restricted right eye movement and decrease in visual acuity. The patient was found to have a 6-cm neurothekeoma involving the maxillary and ethmoid sinuses. To our knowledge, this is the first reported case of neurothekeoma with involvement of the maxillary and ethmoid sinuses. This uncommon lesion should be considered as the differential diagnosis of pediatric soft tissue tumors in the head and neck region.- - - - - - - - - - ranking = 0.077484492002982keywords = soft (Clic here for more details about this article) |
5/18. 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 = 6.077484492003keywords = neoplasm, soft (Clic here for more details about this article) |
6/18. Fine needle aspiration cytology of neurothekeoma. A case report.BACKGROUND: neurothekeoma (NT) is a rare, benign neoplasm of soft parts with a distinctive histologic appearance. To our knowledge, the cytologic findings have not been described before. We present a case of NT with the cytologic features on fine needle aspiration cytology (FNAC). CASE: A 54-year-old female presented with a circumscribed nodule in the left breast. The lesion was evaluated by FNAC. The smears showed an abundant, metachromatic, myxoid matrix with fusiform and epithelioid cells, some binucleated or multinucleated, loose or in groups and sometimes forming concentric whorls. The lesion was removed, and the diagnosis of NT was made after histopathologic study. CONCLUSION: NT is an extremely rare neoplasm in the mammary region. Fusiform and epithelioid cells arranged in concentric whorls in a myxoid tumor of soft tissue are a distinctive characteristic of this neoplasm and can suggest the diagnosis.- - - - - - - - - - ranking = 3.077484492003keywords = neoplasm, soft (Clic here for more details about this article) |
7/18. 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 = 3keywords = neoplasm (Clic here for more details about this article) |
8/18. 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 = 1keywords = neoplasm (Clic here for more details about this article) |
9/18. Cellular neurothekeoma of the maxilla.Neurothekeomas are uncommon benign soft tissue tumors of nerve sheath origin. They occur predominately in the head and neck or upper trunk of children and young adults. A 15-month-old boy presented with an enlarging mass of the right maxilla. Radiologic imaging demonstrated an expansile lesion of the nasomalar region. An incisional biopsy resulted in the diagnosis of neurothekeoma. This lesion should be considered as part of the differential diagnosis of pediatric soft tissue head and neck masses. We discuss the presentation, evaluation, and treatment of these rare benign lesions.- - - - - - - - - - ranking = 0.077484492002982keywords = soft (Clic here for more details about this article) |
10/18. Cellular neurothekeoma with histiocytic differentiation.BACKGROUND: It is generally accepted that the two types of neurothekeoma (myxoid type and cellular type) represent the two poles of a spectrum. This concept, however, has recently been challenged, and cellular neurothekeomas have been suggested as a separate classification and are included in the "fibrohistiocytic" category by some authors. Cellular neurothekeomas have been reported to show negative immunohistochemical staining for histiocytic markers, and PG-M1 is now considered to be the most reliable histiocytic marker. CASE REPORT: We report a case of cellular neurothekeoma. The histopathological features in this case were typical for cellular neurothekeoma. Immunohistochemically, the neoplastic cells were diffusely positive for S-100A6 protein, PGP9.5, CD10, CD68 (KP1), PG-M1, and vimentin, and negative for other antibodies including S-100 protein and factor xiiia. CONCLUSIONS: Cellular neurothekeoma expressing both KP-1 and PG-M1 is considered to show histiocytic differentiation, and may be interpreted as a neoplasm with immature nerve sheath differentiation, incidentally expressing histiocytic markers, or as an undifferentiated neoplasm derived from the neural crest cells of nerve sheath/fibrohistiocyte lineage. These results, such as the concomitant expressions of PGP9.5/S-100A6 and PG-M1/CD68 (KP-1), support the theory of multiple differentiation in cellular neurothekeomas. The significance of the expression of CD10 in this cellular neurothekeoma is unclear.- - - - - - - - - - ranking = 2keywords = neoplasm (Clic here for more details about this article) |
| | Next -> |