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The architecture of optic nerve gliomas with and without neurofibromatosis.

A retrospective clinicopathologic study of 34 patients with optic nerve glioma disclosed two important architectural tumor forms: circumferential-perineural pattern featuring tumor eruption and proliferation in the subarachnoid space correlating with the presence of neurofibromatosis, and an expansile-intraneural pattern correlating with the absence of neurofibromatosis. The 18 patients with neurofibromatosis had a mean age of 4.9 years at presentation and tended to be younger than the 16 patients without neurfibromatosis (mean age, 12 years). Instead of "arachnoidal hyperplasia," electron microscopic studies in the electron microscopic studies in the circumferential-perineural pattern showed tumor astrocytes admixed with reactive meningothelial cells, fibroblasts, and collagen in distended subarachnoid space. Florid invasion of the leptomeninges (arachnoidal gliomatosis) exhibited by many optic nerve gliomas in neurofibromatosis suggests that they are true neoplasms rather than hamartomas, but their frequent location in the distal anterior visual pathway often confers a good clinical prognosis.

Adolescent↗

Neurofibromatosis type II of the head and neck.

Neurofibromatosis type II (NF-II) has been traditionally referred to as "acoustic" neurofibromatosis and is not known to be genetically distinct from classic von Recklinghausen's disease (NF-I). Neurofibromatosis type II is due to a lesion on chromosome 22q, while von Recklinghausen's neurofibromatosis is from a defect on chromosome 17. The approximate incidence of NF-II is one in 50,000, with bilateral acoustic neuromas occurring in over 90% of those with the abnormal gene. We studied a 17-year-old boy with NF-II who presented with bilateral acoustic neuromas and concomitant primary nasopharyngeal meningioma. Less than 30 nasopharyngeal meningiomas have been documented, and the presence of both tumor types in the same individual is unique in the literature.

Adolescent↗

MR imaging of abdominopelvic involvement in neurofibromatosis type 1: a review of 43 patients.

BACKGROUND: Plexiform neurofibromas are a frequent complication of neurofibromatosis type 1. This article discusses MR imaging findings and distribution of plexiform neurofibromas in the abdomen and pelvis. OBJECTIVE: To define the most prevalent patterns of involvement and MR imaging findings in abdominopelvic neurofibromatosis type 1. MATERIALS AND METHODS: We reviewed the MR appearance of abdominopelvic lesions in 23 male and 20 female patients (median age: 16 years) with type 1 neurofibromatosis. The patients were part of a multi-institutional study of 300 patients. Imaging included coronal or sagittal, and axial short tau inversion recovery images. RESULTS: The most common abdominopelvic involvement was in the abdominopelvic wall (n=28, 65%) and lumbosacral plexus (n=27, 63%). Retroperitoneal involvement was frequent (n=15, 35%). Lesions were less often intraperitoneal (21%) (P=0.001). Pelvic disease (n=27, 63%), neural canal involvement (n=18, 42%), and hydronephrosis (n=4, 9%) were also noted. Target-like appearance of plexiform lesions was noted in more than half the patients. CONCLUSION: Abdominopelvic involvement in neurofibromatosis type 1 is primarily extraperitoneal. Although lesions are most prevalent in the abdominopelvic wall and lumbosacral plexus, retroperitoneal and pelvic involvement is common and usually affects important organs. MR imaging added information in the initial and follow-up clinical evaluation of these patients.

Abdomen↗

[Involvement of the large intestine in neurofibromatosis type 1].

This report presents the cases of two female patients aged 54 and 57 years, both with colon involvement of type 1 neurofibromatosis. The first woman had a polypoid neuronal hyperplasia containing small Wagner-Meissner corpuscles, which had allowed identification of the neuronal nature of the lesion in a small mucosal biopsy specimen taken previously. The second patient had an idiopathic megacolon of the sigmoid, which had to be extirpated because of acute obstruction and ileus. Morphological examination revealed a typical plexiform neurofibroma of the bowel wall and neuronal hyperplasia of the colonic mucosa and submucosa, which had obviously caused disordered gut mobility leading to functional stenosis and extreme dilatation of prestenotic bowel parts. Gastrointestinal neurofibromatosis is rare and is characterized morphologically by neuronal hyperplasia of the mucosa and submucosa, sometimes containing small aggregates of ganglion cells by which it can easily be identified. However, in the majority of cases the increase of proliferating mucosal nerve fibres can only be confirmed by S-100 protein immunostaining. Furthermore, solitary, multiple and plexiform neurofibromas are found, but only the last, which arises from mesenteric or subserosal nerves, is virtually pathognomonic for neurofibromatosis. Gastrointestinal neurofibromas are usually late manifestations of the disease, but in exceptional cases they can be the initial sign of neurofibromatosis in patients who have no external stigmata that arouse suspicion. The occurrence of gastrointestinal neurofibromas should therefore lead to a careful search for other features of NF-1 in the affected patients and in their families.

Adenomatous Polyposis Coli↗

Neurofibromatosis type 1, hyperparathyroidism, and osteosarcoma: interplay?

Neurofibromatosis type 1 (NF 1) is a syndrome with a predisposition for benign and malignant tumor development. Of the malignant neoplasms, osteogenic sarcomas are rare but have been described. There are some reports of patients with neurofibromatosis type 1 with a parathyroid adenoma and hyperparathyroidism. Also, there are studies that imply that the parathyroid hormone plays a role in the regulation and modulation of oseogenic sarcomas in vitro. We report about a 50-year-old female suffering from neurofibromatosis type 1, with a 3-year documented history of untreated hyperparathyroidism and a parathyroid adenoma. The patient developed a mandibular osteogenic sarcoma. To our knowledge, this is the first reported case occurring in the mandible. The unusual tumor site for a patient with neurofibromatosis type 1, the conjugation with hyperparathyroidism and the rapid growth of an osteogenic sarcoma are intriguing.

Bone Neoplasms↗

Childhood neurofibromatosis: risk factors for malignant disease.

Forty-five children with both neurofibromatosis and malignant tumors were compared with a pediatric population with neurofibromatosis without tumors to ascertain if any of the clinical manifestations of this disorder were associated with either tumor development or histology. No such factors emerged except that, in most of the optic glioma patients, the neurofibromatosis mutation was paternally inherited. Concordance of histologic tumor types was seen when malignancies occurred in affected family members, similar to that noted in the literature. Although cancer is independent of the other manifestations of neurofibromatosis and these manifestations may vary among family members, it appears that malignant tumors are often concordant when they occur within a family.

Brain Neoplasms↗

Segmental neurofibromatosis.

Two patients had localized multiple cutaneous neurofibromas; one had bilateral involvement of the scalp and the other had true segmental neurofibromatosis. Other signs of neurofibromatosis were absent. Segmental neurofibromatosis may not be related to the generalized types of neurofibromatosis but may be a cutaneous hamartoma.

Aged↗

Branch retinal vein occlusion in a Japanese patient with neurofibromatosis 1.

BACKGROUND: To report an Asian patient with branch retinal vein occlusion secondary to neurofibromatosis 1. CASE: A 64-year-old woman presented with a loss of vision in her right eye of 9-month duration. A diagnosis of neurofibromatosis 1 was made. A general medical examination showed no abnormalities except the signs of neurofibromatosis 1. OBSERVATIONS: Fundus examination of the right eye revealed irregularities of the venous caliber, partial sheathing of the corresponding vein and macular edema. Multiple dilated and tortuous collateral channels and an arteriovenous communication bridged the perfused and nonperfused retina. Fundus examination of the left eye showed a tortuous vein in the temporal region of the fovea. Fluorescein angiography of the right eye confirmed delayed filling in a superotemporal artery and in the corresponding vein. The temporal region of the fovea had large areas of capillary loss. The collaterals were tortuous and mimicked a neovascularization. Fluorescein angiography of the left eye confirmed that the vein in the temporal part of the fovea was tortuous and not leaking. A diagnosis of branch retinal vein occlusion of the superotemporal vein was made. CONCLUSIONS: Neurofibromatosis 1 should be considered in the differential diagnosis of retinal vascular occlusive disease without other risk factors.

Diagnosis, Differential↗

[Tumors diagnosed in 65 patients with type I neurofibromatosis].

BACKGROUND: Type 1 neurofibromatosis patients develop malignant neoplasm more frequently than general population. PATIENTS AND METHOD: We have studied 65 patients with neurofibromatosis type 1 because we intend to know the kind of neoplasms that they have presented. RESULTS: 65 patients (48 men and 17 women) fulfilling type 1 neurofibromatosis criteria have been studied. Globally 67 tumors appeared, from which 47 (70%) were benign and 20 (30%) were malignant. Benign tumors included 25 neurofibromas, 11 central nervous system tumors and 11 extraneurological tumors. Malignant tumors accounted for 6 soft tissue sarcomas, 6 carcinomas, 3 malignant CNS tumors and 2 acute lymphoblastic leukemias. CONCLUSION: Presentation of neoplasms is frequent in type 1 neurofibromatosis and constitutes main death and morbility cause.

Aged↗

Iridocorneal melanoma associated with type 1 neurofibromatosis: a clinicopathologic study.

OBJECTIVE: A clinicopathologic study of an iridocorneal melanoma associated with type 1 (peripheral) neurofibromatosis is presented. DESIGN: Case report with clinicopathologic correlation. PARTICIPANT: A 32-year-old white woman with type 1 neurofibromatosis presented with long-standing blindness of her right eye due to diffuse intrastromal brown corneal discoloration. INTERVENTION: The patient underwent penetrating keratoplasty and the corneal button was inspected. RESULTS: Histopathologic evaluation of the corneal button after penetrating keratoplasty revealed an intrastromal mixed-type malignant melanoma, which stained positively with HMB-45 and S-100 protein and spared the corneal epithelium and limbus. The corneal graft remained transparent, with best-corrected visual acuity of 20/30. Twenty-two months after surgery, the tumor involved the anterior chamber angle and the iris. Three years later, it caused refractory glaucoma necessitating enucleation. The iris tumor did not extend beyond the iris-lens diaphragm and showed the same cytologic features as the corneal stromal tumor. CONCLUSION: To our best knowledge, this is the first report of iridocorneal melanoma associated with peripheral neurofibromatosis. The location of the tumor in the deep corneal stroma, without initial macroscopic involvement of the angle or iris, may suggest that the corneal portion of the tumor may have developed "in situ" rather than as an extension of iris melanoma. The common origin of melanoma cells and Schwann cells from the neural crest and the proliferation of the Schwann cells in neurofibromatosis provides additional support for this hypothesis.

Adult↗

Bilateral dermatomal neurofibromatosis.

Neurofibromatosis is a disease seen in several clinical forms. We describe an unusual case of neurofibromatosis involving a bilateral dermatomal area of the trunk. Family history was negative, and extensive evaluation for other signs of neurofibromatosis was unrevealing. The different forms of neurofibromatosis are briefly discussed with particular emphasis on the segmental type.

Adult↗

Non-von Recklinghausen's neurofibromatosis resembling a giant pigmented nevus.

We report the case of a 30-year-old female patient with non-von Recklinghausen's neurofibromatosis. In our opinion it does not fit within a system of classification recently described. Clinically, the abnormality resembled a giant pigmented nevus; however, light- and electron microscopy findings were consistent with those of a neurofibroma. No other symptoms of classic neurofibromatosis or other diseases were present. The family history showed no evidence of neurofibromatosis. To the best of our knowledge this manifestation of non-von Recklinghausen's neurofibromatosis has not been previously described. The cause and the inheritance pattern of this variant are not clear.

Adult↗

Acute renal insufficiency due to renal infarctions in a patient with neurofibromatosis.

Manifestations of neurofibromatosis in the skin, the eye, and the skeletal and nervous systems have been well documented since the disease was first described in 1882. Stenosing vascular lesions as complications of neurofibromatosis were first reported in 1945. They are being increasingly recognized and most commonly involve the renal artery. Renal artery stenosis (usually proximal), intraparenchymal renal arterial abnormalities, and coarctation of the abdominal aorta often lead to hypertension. However, despite reports of bilateral and severe renal artery disease, renal infarction and resulting renal insufficiency have not been described. We present the case of a 35-year-old woman with neurofibromatosis and chronic hypertension associated with narrowing of right intrarenal arteries. The patient had two separate episodes of left renal infarction documented clinically and radiographically. The second infarct resulted in renal insufficieny. There was no hypercoagulopathy or source for embolism. This case suggests that renal infarction and renal insufficiency are additional complications of neurofibromatosis.

Acute Kidney Injury↗

Hypophosphatemic osteomalacia in neurofibromatosis 1: hypotheses for pathogenesis and higher incidence of spinal deformity.

Osteomalacia is rarely encountered in association with neurofibromatosis 1, characterized by phosphate loss in the urine and its pathogenesis is still unknown. Incidence of spinal deformities in cases of neurofibromatosis 1 associated with osteomalacia seems to be high. Spinal deformities are unlikely to be due to osteomalacia itself. Melatonin deficiency was proposed to be present in cases of neurofibromatosis 1 and to be an operating factor in progression of spinal deformities. We might hypothesize that putative melatonin deficiency in cases of neurofibromatosis 1 might play a role in the pathogenesis of hyperphosphaturea by decreasing sodium-phosphate cotransport, increasing the level of cAMP, the un-antagonized effect of dopamine on phosphate reabsorption and increasing glucocorticoid levels. Parathyroid overactivity that may occur secondary to osteomalacia might have synergistic effects with dopamine and further exaggerate phosphate loss in urine. On the other hand, excess corticosteroid secretion would decrease nocturnal melatonin level. Moreover, in the presence of hypophosphatemia, hypercortisolism might further inhibit melatonin secretion that might lead to progression of spinal deformities in these cases.

Hypophosphatemia, Familial↗

[Multiple gastro-intestinal stromal tumors (GIST) in a patient with type I neurofibromatosis revealed by chronic bleeding: pre-operative radiological diagnosis].

Recent studies have pointed out a high incidence of GIST, usually multiple and of small intestinal location, in patients with type I neurofibromatosis. We here report an additional case, revealed by chronic gastro-intestinal bleeding and diagnosed at pre-operative imaging studies. A 56-year-old patient, with known type I neurofibromatosis, was referred to our department for the exploration of chronic gastro-intestinal bleeding during anti-aggregant therapy. Endoscopical examination was negative. Enteroscanner showed the presence of four tumor lesions, 3 in the jejunum and 1 in the ileum. Segmental surgical resections were performed. At histological examination, 2 of among the 3 jejunal lesions were diagnosed as typical GIST, of low risk of malignancy, CD117+, CD34+, whereas the last jejunal and ileal lesions were identified as fibroid tumors. Mutations of c-kit gene and of the gene coding for PDGF-Ralpha were not detected. Post-operative recovery was uneventful; no recurrent bleeding was observed. Our case report underlines the potential role of enteroscanner in the management of patients with type I neurofibromatosis with possible digestive complications. It also emphasizes the importance of an accurate diagnosis of the digestive tumors associated with type I neurofibromatosis: GISTs are frequent in this setting and must not be misdiagnosed as neurofibromas.

Chronic Disease↗

A patient with neurofibromatosis type 1 and watery diarrhoea syndrome due to a VIP-producing adrenal phaeochromocytoma.

A patient with neurofibromatosis type 1 and watery diarrhoea syndrome due to a VIP-producing adrenal phaeochromocytoma (Case Report). J Intern Med 1999; 246: 231-234. A 43-year-old patient with neurofibromatosis type 1 suffered from watery diarrhoea syndrome induced by excessive production of vasoactive intestinal polypeptide (VIP) in an adrenal phaeochromocytoma. This case report emphasizes that patients with neurofibromatosis are prone to develop more than one disease induced by tumours originating from the neural crest. Since excessive VIP production in a phaeochromocytoma may mask the symptoms of catecholamine overproduction, and in view of the therapeutic consequences, neurofibromatosis patients with hyperVIP-aemia must be checked for the presence of a phaeochromocytoma.

Adrenal Gland Neoplasms↗

Aetiology of spinal deformities in neurofibromatosis 1: new hypotheses.

Neurofibromatosis 1 is a common heritable disorder. The gene causing neurofibromatosis 1 had been recognized and the protein encoded by this gene, neurofibromin, was supposed to play a role in development of various tissues. Neurofibromin was found to have GTP-ase (GAP) domain against small p21 ras. IQGAP1 is another human ras-specific GAP that was found to have calmodulin-binding motifs. Spinal deformities in cases of neurofibromatosis 1 are generally classified into dystrophic and non-dystrophic. Aetiologies of both types are still unknown. We hypothesize that muscle pathology could be the initiating factor for non-dystrophic curves due to neurofibromin deficiency and/or increase of the level of IQGAP. Dystrophic curves might begin as a developmental error due to neurofibromin deficiency in bone. Melatonin deficiency, increased serotonin level with disturbed melatonin-serotonin interactions and calmodulin antagonism by increased IQGAP1 may be responsible for progression of both types of spinal deformities in neurofibromatosis 1.

Calmodulin↗

[Phaeochromocytomas in neurofibromatosis (author's transl)].

Neurofibromas and phaeochromocytomas derive ultimately from ectodermal tissue. It is therefore not surprising that there is an increase in the incidence of phaeochromocytomas in Recklinghausen's neurofibromatosis. When investigating hypertension in patients with neurofibromatosis one must therefore consider the possibility of a phaeochromocytoma as well as vascular involvement by neurofibromatosis. Two patients with neurofibromatosis and phaeochromocytomas are described.

Adrenal Gland Neoplasms↗