Neurofibroma

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Neurofibroma

  • benign neurofibroma
  • plexiform neurofibroma


  • Selected Abstracts


    Cerclage Technique for Repairing Large Circular Defects of the Trunk: Two-Staged Excision of a Plexiform Neurofibroma

    DERMATOLOGIC SURGERY, Issue 7 2008
    TONY N. NAKHLA DO
    First page of article [source]


    Surgical Treatment of a Left Ventricular Neurofibroma

    JOURNAL OF CARDIAC SURGERY, Issue 3 2006
    Kenji Iino M.D.
    We describe a case of left ventricular neurofibroma in a 56-year-old woman with Von Recklinghausen disease. Resection of the tumor with concomitant mitral valve replacement yielded a satisfactory clinical result, and histological examination of the resected tissue confirmed benign neurofibroma. The anatomic distribution of the vagus nerve plexus, which penetrates the epicardium and myocardium and courses over the left ventricular subendocardial surface, provides a tissue source from which this neurogenic tumor may arise. [source]


    Surgical Management of an Unresectable Trigeminal Nerve (V2) Plexiform Neurofibroma

    THE LARYNGOSCOPE, Issue S1 2009
    Urmen Desai MD MPH
    No abstract is available for this article. [source]


    Isolated Plexiform Neurofibroma: Treatment with Three-Dimensional Conformal Radiotherapy,

    THE LARYNGOSCOPE, Issue 7 2004
    Thomas C. Robertson MD
    Abstract Objectives: To present a case of an unusual benign tumor of the tongue treated successfully with radiotherapy. Study Design: Case report. Methods: Retrospective chart review. Results: A 60-year-old man presented with a painful submucosal lesion of the tongue base. Computed tomography showed an infiltrative soft-tissue mass involving the left base of the tongue. Operative biopsy revealed plexiform neurofibroma. Because of the patient's operative risk and the potential morbidity of surgical resection, he was treated with three-dimensional conformal radiotherapy (3DCRT). His treatment was accomplished using a five-field arrangement treating exclusively the mass lesion to a total tumor dose of 60 Gy. After treatment, the patient's tongue pain resolved, and he noted minimal transient xerostomia. Serial follow-up radiographic examinations showed the base of tongue mass to be slightly smaller 4 months after treatment. The most recent follow-up magnetic resonance image reveals a further decrease in size of the mass. The patient is now over 3 years out from treatment. Conclusions: Solitary plexiform neurofibroma of the tongue base is a rare tumor. These benign neoplasms are usually treated with either observation or surgical excision. This case demonstrates that, when significant symptoms necessitate active management, these lesions may be successfully treated with minimal morbidity using 3DCRT. The ability of this technique to deliver a conformal radiation dose to the tumor volume while sparing the surrounding normal tissues may expand the application of radiotherapy in the treatment of these benign lesions of the head and neck. [source]


    Cytohistologic correlations in schwannomas (neurilemmomas), including "ancient," cellular, and epithelioid variants

    DIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006
    Jerzy Klijanienko M.D.
    Abstract Schwannoma accounts for one of the most common benign mesenchymal neoplasms of soft tissues. Although it is well defined in the cytology literature, particular histologic subtypes such as "ancient," cellular and epitheliod variants could be a source of diagnostic difficulties. We have reviewed cytology aspirates and corresponding histologic sections from 34 schwannomas diagnosed at Institut Curie. Histologically, 24 cases were classic, 5 were "ancient," 4 were cellular, and 1 was epithelioid schwannomas. No example of melanotic schwannoma was recorded. Original cytologic diagnosis was schwannoma in 13 (38.2%) cases, benign soft tissue tumor in 11 (32.4%), pleomorphic adenoma in 2 (6%) cases, angioma in 1 (2.9%) case, nodular fasciitis in 1 (2.9%) case, suspicious in 3 (8.8%) cases, and not satisfactory in 3 (8.8%) cases. There were no major differences between classical, "ancient," cellular, and epithelioid variants on cytology smears. Myxoid stroma, mast cells, and intranuclear inclusions were limited to classical subtype. Similarly, cyto-nuclear atypia was more frequent in classical subtype than in other subtypes. Schwannoma should be differentiated from well-differentiated malignant peripheral nerve sheath tumor, neurofibroma, and pleomorphic adenoma, in the last instance particularly for head and neck lesions. Diagn. Cytopathol. 2006;34:517,522. © 2006 Wiley-Liss, Inc. [source]


    How does the Schwann cell lineage form tumors in NF1?

    GLIA, Issue 14 2008
    Steven L. Carroll
    Abstract Neurofibromas are benign tumors of peripheral nerve that occur sporadically or in patients with the autosomal dominant tumor predisposition syndrome neurofibromatosis type 1 (NF1). Multiple neurofibroma subtypes exist which differ in their site of occurrence, their association with NF1, and their tendency to undergo transformation to become malignant peripheral nerve sheath tumors (MPNSTs), the most common malignancy associated with NF1. Most NF1 patients carry a constitutional mutation of the NF1 tumor suppressor gene. Neurofibromas develop in these patients when an unknown cell type in the Schwann cell lineage loses its remaining functional NF1 gene and initiates a complex series of interactions with other cell types; these interactions may be influenced by aberrant expression of growth factors and growth factor receptors and the action of modifier genes. Cells within certain neurofibroma subtypes subsequently accumulate additional mutations affecting the p19ARF -MDM2-TP53 and p16INK4A-Rb signaling cascades, mutations of other as yet unidentified genes, and amplification of growth factor receptor genes, resulting in their transformation into MPNSTs. These observations have been validated using a variety of transgenic and knockout mouse models that recapitulate neurofibroma and MPNST pathogenesis. A new generation of mouse models is also providing important new insights into the identity of the cell type in the Schwann cell lineage that gives rise to neurofibromas. Our improving understanding of the mechanisms underlying the pathogenesis of neurofibromas and MPNSTs raises intriguing new questions about the origin and pathogenesis of these neoplasms and establishes models for the development of new therapies targeting these neoplasms. © 2008 Wiley-Liss, Inc. [source]


    First giant gluteal neurofibroma reported in the literature in a person with haemophilia and its high risk of massive bleeding to death

    HAEMOPHILIA, Issue 4 2005
    J. Fernandez-Delgado
    No abstract is available for this article. [source]


    Metastatic acinic cell carcinoma in a neurofibroma mistaken for carcinosarcoma

    HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2005
    Michael L. Cohn MD
    Abstract Background. Tumor-to-tumor metastasis is a rare, but well-recognized, entity most commonly involving metastatic carcinoma to a mesenchymal neoplasm. We report a case of acinic cell carcinoma of the parotid gland metastatic to a neurofibroma. Methods and Results. A 55-year-old man with a history of a high-grade acinic cell carcinoma of the parotid was seen with a mass at the surgical site and metastatic foci in the scalp 10 months postoperatively. The resection specimen revealed a spindle cell lesion with metastatic foci of high-grade adenocarcinoma, initially diagnosed as a carcinosarcoma. The bland morphology and S-100,positive expression of the spindle cell lesion confirmed the diagnosis of neurofibroma. The high-grade features of the carcinomatous foci and their similarity to the primary tumor confirmed the presence of a tumor-to-tumor metastasis. Conclusion. To our knowledge, this is the first reported case of acinic cell carcinoma metastatic to a neurofibroma, an important entity in the differential diagnosis of biphasic tumors of the head and neck. © 2004 Wiley Periodicals, Inc. Head Neck27: 76,80, 2005 [source]


    Somatic NF1 mutation spectra in a family with neurofibromatosis type 1: Toward a theory of genetic modifiers,

    HUMAN MUTATION, Issue 6 2003
    Verena Wiest
    Abstract Neurofibromatosis type 1 (NF1), an autosomal dominantly-inherited disorder, is mainly characterized by the occurrence of multiple dermal neurofibromas and is caused by mutations in the NF1 gene, a tumor suppressor gene. The variable expressivity of the disease and the lack of a genotype/phenotype correlation prevents any prediction of patient outcome and points to the action of genetic factors in addition to stochastic factors modifying the severity of the disease. The analysis of somatic NF1 gene mutations in neurofibromas from NF1 patients revealed that each neurofibroma results from an individual second hit mutation, indicating that factors that influence somatic mutation rates may be regarded as potential modifiers of NF1. A mutational screen of numerous neurofibromas from two NF1 patients presented here revealed a predominance of point mutations, small deletions, and insertions as second hit mutations in both patients. Seven novel mutations are reported. Together with the results of studies that showed LOH as the predominant second hit in neurofibromas of other patients, our results suggest that in different patients different factors may influence the somatic mutation rate and thereby the severity of the disease. Hum Mutat 22:423,427, 2003. © 2003 Wiley-Liss, Inc. [source]


    Plexiform neurofibromas in neurofibromatosis type 1

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 9 2009
    FNASc, FRAS(Lond.), Virendra N. Sehgal MD
    Plexiform neurofibroma developing in neurofibromatosis type 1 is a fascinating overture whereby diagnosis is primarily based on clinical characteristics, the details of which are outlined. Nonetheless, it is imperative to establish a clear-cut clinical status vis-á-vis the adjoining tissues. Magnetic resonance imaging (MRI) may provide an additional supplement to the diagnosis and an aid to further management of the condition. [source]


    Surgical Treatment of a Left Ventricular Neurofibroma

    JOURNAL OF CARDIAC SURGERY, Issue 3 2006
    Kenji Iino M.D.
    We describe a case of left ventricular neurofibroma in a 56-year-old woman with Von Recklinghausen disease. Resection of the tumor with concomitant mitral valve replacement yielded a satisfactory clinical result, and histological examination of the resected tissue confirmed benign neurofibroma. The anatomic distribution of the vagus nerve plexus, which penetrates the epicardium and myocardium and courses over the left ventricular subendocardial surface, provides a tissue source from which this neurogenic tumor may arise. [source]


    Cutaneous melanocytoneuroma: the first case of a distinctive intraneural tumor with dual nerve sheath and melanocytic differentiation

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 2007
    Ilan Weinreb
    Many melanocytic nevi contain areas similar to nerve sheath tumors (NST) and NSTs with melanin have been described. There are some NSTs with at least partial intraneural location, including neurofibromas, plexiform neurofibromas, granular cell tumors and the recently described, dendritic cell neurofibroma with pseudorosettes. We describe the case of an NST with melanocytic differentiation and intraneural location, for which we suggest the term ,melanocytoneuroma' (MCN). It arose in the skin of a 67-year-old woman with no previous history of melanoma or neurofibromatosis. The lesion presented as a papule and histologically consisted of a dermal nodule without junctional melanocytic activity. The lesion comprised an intraneural proliferation of large epithelioid eosinophilic cells with prominent cell borders imparting a ,plant-like' appearance. The cells were also seen within adjacent nerve twigs and were positive for S100, Melan-A, HMB-45, microphthalmia transcription factor and PGP 9.5. The lesion was entirely surrounded by an epithelial membrane antigen-positive-perineurial coat and the individual tumor cells were invested by laminin and collagen type-IV-positive basal lamina-like material. The lesion did not show any evidence of atypia and following complete excision, no recurrence has been documented. In conclusion, this unusual lesion represents an intraneural proliferation with melanocytic and nerve sheath cell differentiation, to which we have accorded the appellation, MCN. [source]


    Fibrolamellar nerve sheath tumor or sclerotic neurofibroma?

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 11 2006
    Boncheol Goo MD
    [source]


    Melanocytic nevi are associated with neurofibromas in neurofibromatosis, type I, but not sporadic neurofibromas.

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 8 2005
    A study of 226 cases
    Background:, Neurofibromatosis, type 1, is associated with cutaneous melanin pigmentation, but an association with ordinary melanocytic nevi has not been described. Methods:, This retrospective case-control study was designed to see if neurofibromas in patients with neurofibromatosis, type 1 (NF-1) differ from sporadic neurofibromas (SN) in their incidence of associated melanocytic nevi and other histologic features. Slides from 114 NF-1 were compared with 112 SN and 300 intradermal melanocytic nevi (IDN). Results:, Small lentiginous melanocytic nevi were identified over 13 NF-1 (11%) but no SN (P = 0.0002). Compared with other NF-1, NF-1 with nevi were more frequently associated with melanocytic hyperplasia, giant melanosomes and diffuse neurofibroma (P < 0.03). Compared with SN, NF-1 were also more frequently associated with melanocytic hyperplasia, lentigo simplex-like changes, diffuse neurofibroma and plexiform neurofibroma (P < 0.001). Sebaceous hyperplasia (14%), dermal elastosis (9%), lipomatous change (8%), epithelial cysts (4%) and keratin granulomas or folliculitis (3%) were not significantly different in prevalence between NF-1, SN and the control group of IDN. Conclusions:, This study suggests that there is a difference in the potential for melanocytic proliferation in NF-1 compared with SN. NF-1, SN and IDN are associated with a similar range of incidental histologic changes. [source]


    Intradermal spindle cell/pleomorphic lipoma of the vulva: case report and review of the literature

    JOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2002
    Jorge S. Reis-Filho
    Background: Spindle cell/pleomorphic lipoma (SC/PL) is a benign adipose tissue tumor that usually affects the subcutaneous tissues of shoulders, backs, and neck region of middle-aged male patients. Histologically, it is characterized by the presence of primitive CD34-positive spindle cells arranged in short fascicles, bizarre floret-like multinucleated giant cells, mature adipocytes, and a small number of lipoblasts. Recently, an intradermal subset has been described, which mainly affects female patients and presents a wider antomical distribution when compared to the classical variant of SC/PL. Methods: We report a case of intradermal SC/PL affecting the labium majus of a 56-year-old female patient. Results: The histological examination disclosed the typical histological features, however the lesion showed poorly demarcated and infiltrative borders, as well as involvement of dermal nerves. The immunohistochemical analysis according to streptovidin-biotin-peroxidase technique showed immunoreactivity for CD34 and vimentin in the spindle cells, as well as S100 protein and vimentin in the adipocytic cells. Conclusions: To the best of our knowledge, this is the first case of intradermal SC/PL affecting the vulvar region. Care must be taken not to misdiagnosis this rare tumor as well-differentiated liposarcoma, cellular angiofibroma, solitary fibrous tumor, and cutaneous neurofibroma. [source]


    Solitary plexiform neurofibroma: recurrence 32 years after excision

    JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 6 2006
    M Fujiwara
    [source]


    Large recurrent plexiform neurofibroma of the foot and ankle

    MICROSURGERY, Issue 1 2004
    Lee L.Q. Pu M.D., Ph.D.
    Plexiform neurofibroma often causes significant pain, deformity, and functional problems in the affected part of the body. Surgical management of the condition can be challenging, and local recurrence is common because of inadequate resection of the tumor. One patient with a large recurrent plexiform neurofibroma of the foot and ankle was treated successfully with a complete resection of the tumor, followed by a free latissimus dorsi muscle transfer with a skin graft for soft-tissue reconstruction. The patient has regained good contour of the foot and ankle, and has been symptom-free with no evidence of local recurrence in the affected area for 18 months. The authors believe that thorough preoperative planning and state-of-the-art reconstructions, as described here, are the keys to their success. © 2003 Wiley-Liss, Inc. [source]


    In vitro studies of steroid hormones in neurofibromatosis 1 tumors and schwann cells

    MOLECULAR CARCINOGENESIS, Issue 7 2007
    Lauren Fishbein
    Abstract The most common NF1 feature is the benign neurofibroma, which consists predominantly of Schwann cells. Dermal neurofibromas usually arise during puberty and increase in number throughout adulthood. Plexiform neurofibromas, associated with larger nerves, are often congenital and can be life threatening. Malignant peripheral nerve sheath tumors (MPNST) in NF1 are believed to arise from plexiforms in 5%,10% of patients. There are reports of increased potential for malignant transformation of plexiform tumors and increase in dermal neurofibromas, during pregnancy. These observations suggest that steroid hormones influence neurofibroma growth, and our work is the first to examine steroid hormone receptor expression and ligand-mediated cell growth and survival in normal human Schwann cells and neurofibroma-derived Schwann cell cultures. Immunohistochemistry and real-time PCR showed that estrogen receptors (ERs), progesterone receptor (PR), and androgen receptor are differentially expressed in primary neurofibromas and in NF1 tumor-derived Schwann cell cultures compared to normal Schwann cells. However, there is substantial heterogeneity, with no clear divisions based on tumor type or gender. The in vitro effects of steroid hormone receptor ligands on proliferation and apoptosis of early passage NF1 tumor-derived Schwann cell cultures were compared to normal Schwann cell cultures. Some statistically significant changes in proliferation and apoptosis were found, also showing heterogeneity across groups and ligands. Overall, the changes are consistent with increased cell accumulation. Our data suggest that steroid hormones can directly influence neurofibroma initiation or progression by acting through their cognate receptor, but that these effects may only apply to a subset of tumors, in either gender. © 2007 Wiley-Liss, Inc. [source]


    Unusual presentation of a hypoglossal nerve neurofibroma

    ORAL SURGERY, Issue 4 2009
    V. Patel
    Abstract Neurofibromatosis type 1 genetic disorder is an inherited autosomal dominant trait with variable penetrance and expressivity and occurs in one of every 2000,3300 live births. Neurofibromatosis type 2, on the other hand, afflicts only one in approximately 50 000 people. Within these patients, the frequency of intra-oral involvement of neurofibromas has been reported in a range of 4,7%. Alternatively, neurofibromas in the oral cavity minus the presence of a neurofibromatosis disease has been documented but the prevalence is even less than stated earlier making a solitary neurofibroma of the tongue a rare occurrence. This article reports an unusual presentation of a neurofibroma masquerading as a lipoma with the tumour occurring at the base of the tongue. [source]


    Pigmented neurofibroma: Report of two cases and literature review

    PATHOLOGY INTERNATIONAL, Issue 7 2001
    Mayumi Inaba
    Two cases of pigmented neurofibroma of the skin are reported. In case 1, the tumor was removed from the back of a 55-year-old man with no associated neurofibromatosis. In case 2, the tumor was removed from the abdominal wall of a 21-year-old woman with neurofibromatosis. Both tumors consisted of benign, short spindle cells and multiple foci of scattered melanin-laden cells. In case 1, the spindle cells were arranged in a storiform pattern, resembling features of dermatofibrosarcoma protuberans. Immunohistochemically, the spindle cells of both cases were demonstrated to be positive for S-100 protein and CD34. The melanin-laden cells stained positively for HMB-45. This report describes an additional two cases of pigmented neurofibroma that conform to the new diagnostic criteria for this disease. [source]


    Pseudoatrophic Macules Associated with Neurofibromatosis-1

    PEDIATRIC DERMATOLOGY, Issue 2 2009
    CHIEN-SHAN CHIU M.D.
    This clinical presentation of neurofibroma has rarely been reported in patients with neurofibromatosis. [source]


    Localized Hypertrichosis in a Pediatric Patient,What Is the Mechanism for Excess Hair Growth?

    PEDIATRIC DERMATOLOGY, Issue 3 2007
    Kyle Wagamon M.D.
    We highlight an instance of localized hypertrichosis due to an underlying diffuse neurofibroma in a patient with known neurofibromatosis 1. The classification and possible underlying pathogenic mechanisms of localized hypertriehosis in pediatric patients is discussed. [source]


    Isolated Plexiform Neurofibroma: Treatment with Three-Dimensional Conformal Radiotherapy,

    THE LARYNGOSCOPE, Issue 7 2004
    Thomas C. Robertson MD
    Abstract Objectives: To present a case of an unusual benign tumor of the tongue treated successfully with radiotherapy. Study Design: Case report. Methods: Retrospective chart review. Results: A 60-year-old man presented with a painful submucosal lesion of the tongue base. Computed tomography showed an infiltrative soft-tissue mass involving the left base of the tongue. Operative biopsy revealed plexiform neurofibroma. Because of the patient's operative risk and the potential morbidity of surgical resection, he was treated with three-dimensional conformal radiotherapy (3DCRT). His treatment was accomplished using a five-field arrangement treating exclusively the mass lesion to a total tumor dose of 60 Gy. After treatment, the patient's tongue pain resolved, and he noted minimal transient xerostomia. Serial follow-up radiographic examinations showed the base of tongue mass to be slightly smaller 4 months after treatment. The most recent follow-up magnetic resonance image reveals a further decrease in size of the mass. The patient is now over 3 years out from treatment. Conclusions: Solitary plexiform neurofibroma of the tongue base is a rare tumor. These benign neoplasms are usually treated with either observation or surgical excision. This case demonstrates that, when significant symptoms necessitate active management, these lesions may be successfully treated with minimal morbidity using 3DCRT. The ability of this technique to deliver a conformal radiation dose to the tumor volume while sparing the surrounding normal tissues may expand the application of radiotherapy in the treatment of these benign lesions of the head and neck. [source]


    Poliosis circumscripta associated with neurofibromatosis 1

    AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 3 2008
    Cecilia Sandoval-Tress
    SUMMARY A 38-year-old man presented with axillary freckling, multiple café au lait macules and neurofibromas on the scalp, trunk and extremities. In addition, he had a patch of white hair on the right parieto-occipital area overlying a scalp neurofibroma. He was diagnosed with poliosis circumscripta associated with neurofibromatosis 1. [source]


    Giant neurofibroma of the vulva

    AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 1 2005
    Maheshwari AMITA
    No abstract is available for this article. [source]


    Psoriatic skin expresses the transcription factor Gli1: possible contribution of decreased neurofibromin expression

    BRITISH JOURNAL OF DERMATOLOGY, Issue 4 2006
    H. Endo
    Summary Background, Psoriasis is a chronic inflammatory disorder of skin characterized by hyperproliferation of keratinocytes. Intracellular signalling pathways inducing the hyperproliferation of keratinocytes remain to be elucidated. An inhibitor of Hedgehog (Hh) signalling, cyclopamine, was recently reported to clear psoriatic skin lesions, suggesting involvement of the Hh signalling pathway in the hyperproliferation of lesional keratinocytes. We have previously observed activation of the Hh signalling pathway in Schwann cells of plexiform neurofibroma in neurofibromatosis type 1 (NF1), which results from functional loss of the NF1 encoding protein, neurofibromin. In psoriasis, deficiency of neurofibromin expression has been observed in lesional keratinocytes. Objectives, To investigate whether the Hh signalling pathway would be activated in psoriasis and whether inhibition of neurofibromin expression would enhance the activation of the Hh signalling pathway. Methods, Activation of the Hh signalling pathway was examined by protein expression of one of the target genes, GLI1, coding for the transcription factor Gli1. Immunohistochemical studies were performed on seven psoriatic skin samples and seven control normal skin samples with a standard immunoperoxidase technique. mRNA expression of GLI1 was analysed by reverse transcriptase,polymerase chain reaction in HaCaT cells transfected with double-strand small interfering RNA for NF1. Results, Our results showed Gli1 expression in psoriatic skin but not in control normal skin. Inhibition of neurofibromin expression in HaCaT cells upregulated mRNA expression of GLI1. Conclusions, Our findings indicate that the Hh signalling pathway is activated in psoriasis and that neurofibromin deficiency may upregulate the pathway. [source]


    Symptoms associated with malignancy of peripheral nerve sheath tumours: a retrospective study of 69 patients with neurofibromatosis 1

    BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2005
    L. Valeyrie-Allanore
    Summary Background, Neurofibromatosis 1 (NF1) is a common genetic disorder with variable clinical manifestations and an unpredictable course. Plexiform neurofibromas are common complications of NF1. Their malignant transformation is the main cause of mortality in adult patients with NF1. Objectives, To identify clinical factors associated with malignant transformation of plexiform neurofibromas. Methods, Using the database of our neurofibromatosis clinic we included in a retrospective study all patients with NF1 having at least one peripheral nerve sheath tumour for which they underwent surgery or surgical biopsy. Predictive values for malignant transformation of three clinical symptoms, i.e. pain, enlargement of mass and neurological symptoms, were evaluated in association with histological parameters. Results, Of 69 patients studied, 48 had at least one plexiform neurofibroma and 21 had a malignant peripheral nerve sheath tumour. Only enlargement of the tumour had high negative and positive predictive values for malignant transformation: 0·92 and 0·95, respectively. In multivariate analysis, tumour enlargement was independently associated with malignant transformation (odds ratio 167·8, 95% confidence interval 14·0,2012·1). Conclusions, From a practical point of view, pain, neurological deficit and enlargement of a pre-existing peripheral nerve sheath tumour in NF1 must lead to deep surgical biopsy to rule out malignant transformation. [source]


    Immunohistochemical staining of cutaneous tumours with G-81, a monoclonal antibody to dermcidin

    BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2004
    Y. Minami
    Summary Background Recently, the novel antimicrobial peptide named dermcidin (DCD) was reported in human eccrine sweat glands. Objectives We investigated the expression of DCD in a variety of cutaneous tumours in order to assess the usefulness of the monoclonal antibody (G-81), which recognizes a fragment of DCD. Patients/methods We studied the immunoreactivity of the G-81 antibody on 197 cutaneous tumours. Results A total of 13 of 26 cutaneous mixed tumours showed substantial immunoreactivity. In contrast all the following cases were completely unreactive: (i) epithelial tumours (seborrhoeic keratosis, squamous cell carcinoma, Bowen's disease, actinic keratosis, genital Paget's disease); (ii) follicular tumours (basal cell carcinoma, trichilemmoma, trichoepithelioma, trichoblastoma, keratoacanthoma, proliferating trichilemmal tumour, pilomatricoma); (iii) melanocytic tumours (malignant melanoma, naevus cell naevus, Spitz naevus, blue naevus); (iv) neural tumours (schwannoma, neurofibroma, Merkel cell neoplasm); (v) mesenchymal tumours (soft fibroma, dermatofibroma, dermatofibrosarcoma protuberans, vascular leiomyoma, leiomyosarcoma, lipoma, juvenile xanthogranuloma, angiomyoma); and (vi) other sweat gland tumours (poroid neoplasms, syringoma, cylindroma, clear cell hidradenoma, spiradenoma, syringoid eccrine carcinoma, mucinous carcinoma, apocrine cystadenoma, syringocystadenoma papilliferum, apocrine adenocarcinoma). Twenty-six cutaneous mixed tumours were considered from histopathological findings to be the apocrine type, but 13 of 26 mixed tumours contained some DCD-immunopositive cells that possibly differentiate into eccrine secretory glands. Conclusions We found the expression of DCD in tubular structures of 50% of cutaneous mixed tumours with apocrine differentiation. These results suggest that a number of cutaneous mixed tumours show both eccrine and apocrine differentiation in the same neoplasm. [source]


    Thyroid gland neurofibroma in a NF1 patient

    ACTA NEUROLOGICA SCANDINAVICA, Issue 1 2002
    M. Anagnostouli
    Neurofibromas are a hallmark of neurofibromatosis type 1 (NF1). They are usually benign and rarely present in the thyroid gland region. There is a suspected association between NF1 and intramedullary thyroid carcinoma and there is a well-known association between NF1 and pheochromocytoma. Here, we present a 55-year-old man with typical symptoms of NF1, whose course was complicated by a neurofibroma of the thyroid gland. His clinical spectrum of symptoms included bilateral cataract established before the age of 35 years, quadriparesis and an intrathoracic mass. The patient died because of abdominal carcinomatosis of unknown origin. The rarity of thyroid gland neurofibroma is discussed here, emphasizing the importance of early detection of these and other NF1 complications, also including the risk of malignant transformation with lethal outcome. [source]


    Unusual localization of a plexiform neurofibroma in a child with neurofibromatosis 1

    CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2008
    G. Fabrizi
    No abstract is available for this article. [source]