Long-term follow-up of von Recklinghausen neurofibromatosis. Survival and malignant neoplasms

Survival data for patients with malignant schwannoma

Malignant schwannomas are uncommon sarcomas that arise from the sheath of Schwann surrounding peripheral nerve fibers. These tumors may arise spontaneously in adult patients or may occur with reportedly increased frequency in patients with neurofibromatosis Type I. The tumors have had a reputation for malignancy with rapid metastasis, especially when they arise in relation to neurofibromatosis. We have reviewed the experience of the connective tissue oncology unit with patients with these tumors during the past 25 years. There were 80 malignant schwannomas identified in 41 females and 39 males with a mean age of 36 +/- 17 years. The largest numbers of tumors were seen in the thigh, shoulder, and pelvis but they also occurred in more central (abdomen and thorax) and distal (forearm, hand and foot) locations. The Musculoskeletal Tumor Society stages showed that the majority of the patients had Stage II (high grade but not metastasized) tumors; however, additionally, 10 of the patients had metastases at outset (Stage III). Patient gender was not a factor but stage was a notable determinant of survival. Anatomic location also had a significant effect. Overall, the entire series of patients had a survival of 85% at 11 +/- 5 years and even more remarkable was the fact that there was no difference between the numbers and outcome statistics for tumors arising spontaneously and those occurring in patients with neurofibromatosis.

Susceptibility to astrocytoma in mice mutant for Nf1 and Trp53 is linked to chromosome 11 and subject to epigenetic effects

Astrocytoma is the most common malignant brain tumor in humans. Loss of the p53 signaling pathway and up-regulation of the ras signaling pathway are common during tumor progression. We have shown previously that mice mutant for Trp53 and Nf1 develop astrocytoma, progressing to glioblastoma, on a C57BL/6J strain background. In contrast, here we present data that mice mutant for Trp53 and Nf1 on a 129S4/SvJae background are highly resistant to developing astrocytoma. Through analysis of F1 progeny, we demonstrate that susceptibility to astrocytoma is linked to chromosome 11, and that the modifier gene(s) responsible for differences in susceptibility is closely linked to Nf1 and Trp53. Furthermore, this modifier of astrocytoma susceptibility is itself epigenetically modified. These data demonstrate that epigenetic effects can have a strong effect on whether cancer develops in the context of mutant ras signaling and mutant p53, and that this mouse model of astrocytoma can be used to identify modifier phenotypes with complex inheritance patterns that would be unidentifiable in humans. Because analysis of gene function in the mouse is often performed on a mixed C57BL/6,129 strain background, these data also provide a powerful example of the potential of these strains to mask interesting gene functions.

Nerve tumors of the hand and upper extremity

Tumors of peripheral nerve origin are usually slow growing and minimally symptomatic, making differentiation from other soft tissue neoplasms difficult. Yet failure to recognize a nerve tumor may result in irreversible loss of neurologic function. This article provides current information on the history, pathologic identification, and treatment of upper extremity nerve tumors. Other neoplastic and tumor-like lesions that occur within the peripheral nerve are also considered.

Hereditary pancreatic endocrine tumours

The two main types of hereditary pancreatic neuroendocrine tumours are found in multiple endocrine neoplasia type 1 (MEN-1) and von Hippel-Lindau disease (VHL), but also in the rarer disorders of neurofibromatosis type 1 and tuberous sclerosis. This review considers the major advances that have been made in genetic diagnosis, tumour localization, medical and surgical treatment and palliation with systemic chemotherapy and radionuclides. With the exception of the insulinoma syndrome, all of the various hormone excess syndromes of MEN-1 can be treated medically. The role of surgery however remains controversial ranging from no intervention (except enucleation for insulinoma), intervening for tumours diagnosed only by biochemical criteria, intervening in those tumours only detected radiologically (1-2 cm in diameter) or intervening only if the tumour diameter is > 3 cm in diameter. The extent of surgery is also controversial, although radical lymphadenectomy is generally recommended. Pancreatic tumours associated with VHL are usually non-functioning and tumours of at least 2 cm in diameter should be resected. Practice guidelines recommend that screening in patients with MEN-1 should commence at the age of 5 years for insulinoma and at the age of 20 years for other pancreatic neuroendocrine tumours and variously at 10-20 years of age for pancreatic tumours in patients with VHL. The evidence is increasing that the life span of patients may be significantly improved with surgical intervention, mandating the widespread use of tumour surveillance and multidisciplinary team management.

The course of neurofibromatosis type 1 on immunosuppression after lung transplantation: report of 2 cases

We describe 2 patients with neurofibromatosis type 1 (NF1) who underwent lung transplantation. Case 1 reports a patient with NF1 with no complications 5 years after bilateral lung transplantation. Case 2 details a patient with NF1 diagnosed with both post-transplant lymphoproliferative disorder (PTLD) and massive intra-abdominal sarcoma consistent with a malignant nerve sheath tumor 9 months after lung transplantation. There was no clinical evidence of sarcoma preceding or immediately following lung transplant as demonstrated by a normal abdominal sonogram 3 months post-transplantation. Although an increased risk for cancer has been documented in NF1, the rapid malignant degeneration of a neurofibroma following transplantation raises concern about immunosuppression and transplantation candidacy among individuals with NF1.

Gynaecomastia, neurofibromatosis and breast cancer

Gynaecomastia commonly affects pubertal boys. We report a rare case of bilateral ductal carcinoma in situ found incidentally after breast reduction surgery in a young man with neurofibromatosis.

Neurofibromatosis in children with Rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma study IV

We identified all children enrolled in the Intergroup Rhabdomyosarcoma Study Group-IV with neurofibromatosis type I (NF1) and rhabdomyosarcoma. Among 1025 eligible patients, 5 (0.5 %) had NF1. Three children had relapses, two of whom died of progressive disease. Patients with NF1 and rhabdomyosarcoma should be treated with intensive contemporary therapy protocols.

Primary malignant peripheral nerve sheath tumor of the cauda equina in a child case report

STUDY DESIGN

A case report of primary malignant peripheral nerve sheath tumor (MPNST) of the cauda equina in a child is presented, and the literature is reviewed.

OBJECTIVE

To discuss the problems involved in the treatment of primary intradural MPNSTs.

SETTING

A department of orthopaedic surgery in Japan.

METHODS

A 4-year-old boy complained of low-back pain radiating to the left calf. MRI revealed an intradural tumor at L3-L5 level. Following laminectomy of L3, L4 and L5, the tumor was removed en bloc. Based on pathological and immunohistological findings, the tumor was diagnosed as an MPNST.

RESULTS

Although adjuvant chemotherapy was administered local recurrence and cerebral and spinal metastases of the tumor were found 6 months after the operation. Following additional incomplete removal of the recurrent tumor, radiation therapy was administered. Although recurrent and metastatic tumors disappeared or diminished in size by radiation, tumors increased in size thereafter, despite additional adjuvant chemotherapy. At 21 months after the first operation, he died of pneumonia.

CONCLUSIONS

Reported clinical outcomes for patients with primary intradural MPNST are very poor. Although no gold standard for the treatment of tumors has been established yet, surgical removal of tumors combined with postoperative high-dose radiation may be recommended.

Malignant Peripheral Nerve Sheath Tumor in the Anterior Skullb Base Associated With Neurofibromatosis Type 1-Case Report-

A 36-year-old man presented with a tumor in the anterior skull base manifesting as headache and visual disturbance. Neurofibromatosis type 1 (NF-1) was identified in early childhood in the patient, and also in his father. Subtotal excision of the tumor was performed, leaving the portion extending outside of the cranium. The histological diagnosis was malignant peripheral nerve sheath tumor. Local radiotherapy was instituted postoperatively. Facial paralysis and dysphagia appeared 7 months after the first operation. Magnetic resonance imaging revealed new lesions in the lateral ventricle and around the brainstem. These tumors were also subtotally excised, but the patient died 10 months after the first operation. The tumor very likely originated from the meningeal branch of the trigeminal nerve. Treatment of such tumors developing inside the cranium should include the widest resection possible, followed by irradiation of the entire neuraxis including the spinal cord to inhibit dissemination through the cerebrospinal fluid. Treatment should be started as quickly as possible if the tumor is associated with NF-1, because of the poor prognosis associated with this condition.

Non-neurogenic sarcomas in four children and young adults with neurofibromatosis type 1

It is well known that children and young adults with neurofibromatosis type 1 (NF1) have a higher risk for non-neurogenic sarcomas than the general population, in addition to an increased risk for malignant peripheral nerve sheath tumor. When non-neurogenic sarcomas occur in early childhood, a subsequent malignant peripheral nerve sheath tumor can occur as a second malignant neoplasm, especially after alkylating agent chemotherapy and irradiation. This report includes the clinicopathologic features of non-neurogenic sarcomas and secondary malignant peripheral nerve sheath tumor in the context of four cases of NF1. The purpose is to emphasize that early diagnosis of NF1 and recognition of potential manifestations of non-neurogenic sarcomas are important for clinical care of these patients and their families.

Genetics of Neurofibromatosis 1-Associated Peripheral Nerve Sheath Tumors

Neurofibromatosis 1, an inherited disorder that affects 1/3500 individuals worldwide, predisposes to the development of benign and malignant peripheral nerve sheath tumors. The disorder results from inactivation of one of the NFI genes. The second NFI gene is typically inactivated in Schwann cells during tumor formation. This article reviews the different types of genetic alterations in NFI in both constitutional and tumor tissues and genetic alterations of other genes that may affect tumorigenesis. These studies have provided insight into the genetic basis of both the variable expression of the disorder and of benign and malignant peripheral nerve sheath tumorigenesis.

Cochlear implantation in a patient with neurofibromatosis type 1 and profound hearing loss: evidence to support a cochlear site of lesion

OBJECTIVE

To determine the efficacy of cochlear implantation in an individual with neurofibromatosis type 1 and profound hearing loss and to determine, to the extent possible in a living subject, the site of lesion of the hearing loss in an individual with neurofibromatosis type 1.

STUDY DESIGN

Postoperative assessment of an adult male with neurofibromatosis type 1.

SETTING

The study was completed in the Departments of Otolaryngology and Audiology, University of Massachusetts Medical Center, Massachusetts.

PATIENTS

One adult male with neurofibromatosis type 1 and bilateral, chiefly profound, sensorineural hearing loss.

INTERVENTIONS

The subject underwent cochlear implantation as treatment of bilateral, chiefly profound sensorineural hearing loss.

MAIN OUTCOME MEASURES

Outcome measures include results of electrical auditory brainstem response testing, electrical compound action potential measures, and speech recognition scores.

RESULTS

Results of testing revealed expected latencies of waves II, III, and V of the electrical auditory brainstem response, measurable compound action potentials across virtually the entire length of the electrode array, and high levels of open-set, auditory-only speech understanding.

CONCLUSIONS

This is the first case report describing the outcome of cochlear implantation in a patient with neurofibromatosis type 1. Composite test results support the absence of VIIIth nerve degeneration or other anomalies, indicating a cochlear site of lesion for the hearing loss in this patient. Based on the results of this investigation, standard cochlear implantation should be considered a viable option and the first line of therapy for the treatment of bilateral, severe to profound sensorineural hearing loss in patients with neurofibromatosis type 1 and normal, VIIIth nerve radiographic findings.

Cytogenetic characterization of three malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNST) are soft tissue sarcomas occurring frequently in patients with neurofibromatosis 1. We present three fully karyotyped cases of MPNST revealing aberrant near-triploid karyotypes. In all three cases we found deletions of chromosome arms or chromosomes 1p, 10q, 9, and 15, as well as gain of chromosome 7 in two NF1-associated cases and gain of chromosome 8 in an NF1-associated and a sporadic case. The chromosomal region of the NF1 gene was cytogenetically unchanged in all cases, whereas two MPNST cases showed losses of the region 22q harboring the locus of the NF2 gene.

Pediatric soft tissue sarcomas

Many of the soft tissue sarcomas that occur in children are of the same histology as those in adults; however, the relative prevalence of these sarcomas is different between children and adults. In some cases, the biologic behavior of pediatric sarcomas is more benign than that in adults. Treatment for sarcomas in children is also different. Pediatric sarcomas are more commonly responsive to chemotherapy. Furthermore, in children who are still growing, surgery and radiation are associated with higher morbidity than in adults. This article discusses the diagnosis and treatment of rhabdomyosarcoma and undifferentiated sarcomas, with an emphasis on surgical considerations, and the diagnosis and treatment of nonrhabdomyosarcomatous soft tissue sarcomas in children.

Prognostic factors of CNS tumours in Neurofibromatosis 1 (NF1): a retrospective study of 104 patients

In addition to multiple peripheral neurofibromas, Neurofibromatosis 1 (NF1) predisposes to CNS tumours. Most of them are pilocytic astrocytomas, arise in children and are located in the optic pathways or in the brainstem. The majority are indolent, but factors predictive of poor prognosis have yet to be identified. Furthermore, the incidence and natural history of gliomas of a higher grade, arising in adults or involving other locations are largely unknown in NF1. In order to address these issues, we performed a retrospective study of 104 patients followed in seven French centres between 1982 and 2000. Inclusion criteria were a diagnosis of NF1, according to the National Institutes of Health criteria, and the presence of a CNS tumour, regardless of type, location or age of onset. The series included 88 children (age range 3 months to 17 years) and 16 adults (age range 19-52 years). The median follow-up was 5.6 years. One hundred and twenty-seven CNS tumours were observed in the 104 patients. Eighty-four (66%) were optic pathway tumours (OPT) and 43 (34%) extra-optic pathway tumours (extra-OPT) (brainstem: n = 21; other locations: n = 22). Twenty-one patients (20%) had multiple CNS tumours. OPT were symptomatic in 50 patients and extra-OPT in 19. Main clinical findings at presentation included visual loss (n = 29; 58%) and precocious puberty (n = 5; 10%) for OPT, increased intracranial pressure (n = 9; 48%) for extra-OPT. Fourteen out of the 27 symptomatic tumours with histology were pilocytic astrocytomas. The overall survival rate was 90% at 5 years (95% confidence interval 82-95%). Extra-optic location, tumour diagnosis in adulthood and symptomatic tumours were independent factors associated with shorter survival time (P < 0.05, Cox model). Radiotherapy for OPT was associated with vascular complications (ischaemic strokes) and growth hormone deficiency in 32 and 46% of patients, respectively. In conclusion, mortality is high in extra-OPT, particularly in adults, whereas OPT are only exceptionally life-threatening. Radiotherapy of OPT is associated with an important morbidity in NF1.

BRCA1-related malignancies in a family presenting with von Recklinghausen's disease

BACKGROUND

The association between neurofibromatosis and gynecologic malignancies is rarely reported in the literature. Both BRCA1 and NF1 genes are located on the long arm of chromosome 17.

CASE

We have observed a pedigree showing several individuals affected by both type 1 neurofibromatosis (NF1) and breast or coelomatic cancers. The number of individuals affected, their degree of relationship, and the early age at onset were suggestive of an hereditary breast/ovarian cancer syndrome. Linkage analysis was performed in order to establish whether markers in the chromosome 17 region containing the BRCA1 and NF1 loci were shared by affected individuals. Screening for BRCA1 mutations was performed by PTT and SSCP. Analysis of chromosome 17 DNA markers in the five family members tested show that three individuals affected by both NF1 and carcinomas share a common haplotype including the NF1 and BRCA1 loci on chromosome 17. Mutation analysis showed the presence of a nonsense mutation within BRCA1 exon 12 in two individuals, mother and daughter, affected by breast and peritoneal cancer, respectively, as well as in the son, who had rectal cancer at the early age of 27 years. All three subjects also had NF1.

CONCLUSION

The concurrence of NF1 and hereditary breast/ovarian cancer in this family is likely due to the presence of two linked mutations at the NF1 and BRCA1 loci.

Orthopaedic manifestations of neurofibromatosis in children: an update

Neurofibromatosis is one of the most common genetic disorders affecting mankind. Despite extensive basic science research, the diagnosis still is based largely on well-defined clinical criteria, which often present gradually during childhood. Approximately 50% of patients have significant musculoskeletal manifestations, with scoliosis and congenital pseudarthrosis of the tibia most common. Approximately 20% of children with Type I neurofibromatosis present with scoliosis with or without the classic dystrophic features, such as vertebral scalloping and rib penciling. Dystrophic curves portend rapid progression and require early fusion. Surgical treatment often is challenging because of the common presence of neurofibromas adjacent to the spinal cord, significant multiplanar deformity, and poor bone quality. Congenital pseudarthrosis of the tibia also continues to present significant difficulties. The use of a brace is the mainstay of early treatment, whereas intramedullary rodding commonly is used for operative fixation. Grafting of the free fibula and correction using techniques of distraction and compression histiogenesis with Ilizarov fixators have been reported for refractory cases with varying degrees of success. Multiple heroic, operative attempts may have a tremendous toll on the quality of life of affected children through their early childhood. In addition to these and other distinctive musculoskeletal lesions, affected children often suffer from various medical problems.

Neurofibromatosis 1: clinical manifestations and diagnostic criteria

Neurofibromatosis 1 occurs in 2 to 3 people per 10,000. The most frequent clinical features are café-au-lait macules, neurofibromas, intertriginous freckling, Lisch nodules, and learning disabilities, but optic and other gliomas, malignant peripheral nerve sheath tumors, and characteristic osseous lesions also can be present. Two striking aspects of neurofibromatosis 1 are its progressive nature and its extreme variability. This article reviews the natural history and some important clinical manifestations of neurofibromatosis 1, with emphasis on features that constitute the standard diagnostic criteria. The pathogenic implications of these clinical manifestations are also considered.

Losses in chromosomes 17, 19, and 22q in neurofibromatosis type 1 and sporadic neurofibromas: a comparative genomic hybridization analysis

Neurofibromatosis type 1 (von Recklinghausen's NF1) is an autosomal dominant disease associated with an increased risk of benign and malignant neoplasia including malignant peripheral nerve sheath tumors (MPNSTs). In this study, we employed comparative genomic hybridization (CGH) to determine changes in the relative chromosome copy number in 24 patients with neurofibromas, including 12 NF1-associated and 12 sporadic cases. Differences in the frequency and distribution of chromosomal imbalances were observed in both NF1-asociated and sporadic neurofibromas. Chromosomal imbalances were more common in NF1-associated tumors than in sporadic neurofibromas. In both groups, the number of losses was higher than the number of gains, suggesting a predominant role of tumor suppressor gene in tumorigenesis. A number of new chromosomal imbalances were noted including chromosomes 17, 19, and chromosome arm 22q, which may be related to oncogenes or tumor suppressor genes in neurofibromas. In NF1-associated neurofibromas, the most frequent losses were found in chromosome 17 (the minimal common regions were 17p11.2-->p13 in nine cases and 17q24-->q25 in six cases) and 19p (19p13.2 in nine cases). In addition, both NF1-associated and sporadic neurofibromas often exhibited losses at chromosome arms 19q and 22q (in NF1 tumors, the minimal common regions were 19q13.2-->qter in seven cases).

Neurofibromatosis type 1 and sporadic optic gliomas

AIMS

To compare the natural history of sporadic optic glioma with those associated with neurofibromatosis type 1 (NF1).

METHODS

Optic glioma cases were identified using both the Manchester Children's Tumour Registry (CTR) and the North West Regional NF1 Database (NF1DB), with detailed information on natural history available from the former (in 34 of 36 cases identified).

RESULTS

A total of 52 cases over a period of 41 years were identified. From the 34 whose natural history was known, almost all (n = 31) were symptomatic, with mean ages of presentation of 4.5 and 5.1 years for NF1 and sporadic cases respectively. The majority (n = 22) presented with visual impairment, seven of whom were blind in at least one eye. Sporadic cases were over twice as likely as NF1 to have visual impairment. Recurrence occurred in 12 patients. Fewer NF1 patients died as a direct result of their optic glioma, but overall mortality and 5 and 10 year survival rates between the two groups were similar. All five primary (non-metastatic) second central nervous system (CNS) tumours occurred in NF1 cases, two of these following radiotherapy.

CONCLUSIONS

Symptomatic sporadic optic gliomas presented with impaired vision more frequently and were more aggressive than NF1 optic gliomas. Only optic glioma cases with NF1 were at risk of developing a second CNS tumour. Aggressive treatment of sporadic optic gliomas and early surveillance of NF1 optic gliomas may be required. The use of radiotherapy in these children requires further clarification.

Frequent genomic imbalances in chromosomes 17, 19, and 22q in peripheral nerve sheath tumours detected by comparative genomic hybridization analysis

Comparative genomic hybridization (CGH) was used to detect changes in relative chromosome copy number in 50 cases of peripheral nerve sheath tumour (PNSTs), including nine malignant peripheral nerve sheath tumours (MPNSTs), 27 neurofibromas (with three plexiform neurofibromas) and 14 schwannomas. Chromosome imbalances were frequently detected in benign as well as malignant PNSTs. In both NF1-associated and sporadic MPNSTs, the number of gains was higher than the number of losses, suggesting proto-oncogene activation during MPNST progression. NF1-asociated MPNSTs exhibited gains of chromosomes 17q and X (2/4 cases each), whereas sporadic MPNSTs showed gains of chromosome 4q (3/5 cases). On the other hand, in benign neurofibromas and schwannomas, the number of losses was higher than the number of gains, suggesting a predominant role of tumour suppressor genes in tumourigenesis. Both sporadic and NF1-associated neurofibromas exhibited losses at chromosome 22q in more than 50% of cases. These chromosomal regions may contain common chromosomal abnormalities characteristic of both types of neurofibromas. In NF1-associated neurofibromas, most frequent losses were found in chromosomes 17 [17p11.2-p13 in nine cases (60%); 17q24-25 in 6 cases (40%)] and 19 [19p13.2 in eight cases (53%); 19q13.2-qter in eight cases (53%)], whereas in sporadic neurofibromas and schwannomas losses of chromosomes 17 and 19 were detected in less than 50% of cases. Since this 17p11.2-p13 region is known to contain the tumour suppressor gene TP53, patients with NF1 may be at high risk of malignant neoplasms including MPNSTs. Gains were more frequently detected in plexiform neurofibromas (2/3 cases) than other benign tumours, suggesting proto-oncogene activation in tumourigenesis of plexiform neurofibroma. The significance of the losses of chromosome 19 in these cases is not clear at present, but in NF1-associated neurofibromas, the presence of some as yet unknown tumour suppressor genes on chromosome 19 cannot be ruled out.

Malignant peripheral nerve sheath tumor of the vulva: a multimodal treatment approach

BACKGROUND

Malignant peripheral nerve sheath tumors (MPNSTs) are rare in the gynecological population and have a high risk for local and distant failures. Multimodal management of a patient with MPNST of the vulva and review of the literature are outlined.

CASE

A 34-year-old woman presented with a complaint of a rapidly increasing pelvic mass, pain, and difficulty ambulating. A disfiguring 20 x 20-cm vulvar mass was identified and a recurrent MPNST diagnosed. Therapy included external-beam radiation, anterior pelvic exenteration with pelvic reconstruction, and adjuvant chemotherapy without complication.

CONCLUSION

It is recommended that for malignant peripheral nerve sheath tumors of the vulva, complete surgical resection be performed with adjuvant radiation and chemotherapy in selected cases.

Cardiovascular disease in neurofibromatosis 1: report of the NF1 Cardiovascular Task Force

PURPOSE

Patients with neurofibromatosis 1 (NF1) are at increased risk for a variety of cardiovascular disorders, but the natural history and pathogenesis of these abnormalities are poorly understood.

METHODS

The National Neurofibromatosis Foundation convened an expert task force to review current knowledge about cardiovascular manifestations of NF1 and to make recommendations regarding clinical management and research priorities related to these features of the disease.

RESULTS

This report summarizes the NF1 Cardiovascular Task Force's current understanding of vasculopathy, hypertension, and congenital heart defects that occur in association with NF1. Recommendations are made regarding routine surveillance for cardiovascular disease and diagnostic evaluation and management of cardiovascular disorders in individuals with NF1.

CONCLUSION

Our understanding of the natural history and pathogenesis of cardiovascular disease in NF1 has improved substantially in the past few years, but many clinically important questions remain unanswered.

Malignant peripheral nerve sheath tumours in neurofibromatosis 1

BACKGROUND

Cross sectional studies have shown that 1-2% of patients with neurofibromatosis 1 (NF1) develop malignant peripheral nerve sheath tumours (MPNST). However, no population based longitudinal studies have assessed lifetime risk.

METHODS

NF1 patients with MPNST were ascertained from two sources for our north west England population of 4.1 million in the 13 year period 1984-1996: the North West Regional NF1 Register and review of notes of patients with MPNST in the North West Regional Cancer Registry.

RESULTS

Twenty-one NF1 patients developed MPNST, equivalent to an annual incidence of 1.6 per 1000 and a lifetime risk of 8-13%. There were 37 patients with sporadic MPNST. The median age at diagnosis of MPNST in NF1 patients was 26 years, compared to 62 years in patients with sporadic MPNST (p<0.001). In Kaplan-Meier analyses, the five year survival from diagnosis was 21% for NF1 patients with MPNST, compared to 42% for sporadic cases of MPNST (p=0.09). One NF1 patient developed two separate MPNST in the radiation field of a previous optic glioma.

CONCLUSION

The lifetime risk of MPNST in NF1 is much higher than previously estimated and warrants careful surveillance and a low threshold for investigation.

Neurofibromatosis diagnosed on CT with MR correlation

We report a young man with asymptomatic neurofibromatosis type-1 initially diagnosed on CT. CT demonstrated the typical lesions of this disorder: extensive cervical, thoracic, abdominal and pelvic masses and spinal alterations. The symmetrical distribution and the location of the lesions as well as their attenuation are characteristic of NF-1 and may be considered diagnostic for this disease.

Proteus syndrome in adulthood

Proteus syndrome is a very rare congenital condition comprising malformations and overgrowth of multiple sorts of tissue. It was described for the first time in 1979 and was termed Proteus syndrome in 1983. The authors describe a 37-year-old patient who was diagnosed initially as having Klippel-Trenaunay-Weber syndrome at the age of 10 years. The patient was operated for a major thoracic lymphatic malformation, which caused functional problems. The operation at older age for this large lymphatic malformation proved to be complex. In addition, the authors address the difficulties in diagnosing Proteus syndrome. Vascular malformations causing functional problems in adulthood require major surgical procedures with a high risk of postoperative complications.

Management issues in massive pediatric facial plexiform neurofibroma with neurofibromatosis type 1

BACKGROUND

Plexiform neurofibroma is a relatively common but potentially devastating manifestation of neurofibromatosis type 1 (NF1). Surgical management is the mainstay of therapy, but within the head and neck region it is limited by the infiltrating nature of these tumors, inherent operative morbidity, and high rate of regrowth.

METHOD

We describe a case of a 7-year-old girl with neurofibromatosis type 1 and a massive facial plexiform neurofibroma with the aim of emphasizing the treatment and timing issues involved in the management of this difficult problem. A MEDLINE search (1966 through December 2000) was carried out, and pertinent literature on the subject was reviewed.

RESULT

The patient described in this case report was carefully observed for a period of 6 years from diagnosis before surgical excision of the tumor was undertaken with an uneventful recovery.

CONCLUSION

Surgical management remains the mainstay of treatment for these locally invasive tumors, but functional disturbances are almost inevitable in resecting substantial tumors involving the head and neck region. The indication and timing of surgery in pediatric patients therefore needs to be carefully weighed against the physical and psychologic consequences of treatment.

[Neurofibromatosis 1: recommendations for management]

Twenty experts, members of a French medical network devoted to neurofibromatosis 1 have elaborated recommendations for the management of the disease. Bibliography was obtained through a Medline of articles from 1966 to 1999 for the terms neurofibromatosis, NF1, neurofibroma and from textbooks. A consensual document was written taking into account extracted data. An annual careful clinical examination is recommended except in cases with complications. Screening investigations are not recommended due to the rarity of complications, generally symptomatic and easily detected during the clinical follow-up. The only controversial exception might be magnetic resonance imaging for early detection of optic pathway gliomas in young children. A co-ordinated follow-up in specialised multidisciplinary centres, providing patients with a rational management, is recommended.

Ampullary adenocarcinoma in neurofibromatosis type 1. Case report and literature review

Periampullary tumors in patients affected by Neurofibromatosis Type 1 (NF-1) are usually carcinoids or stromal tumors and, rarely, adenocarcinomas. We report a case of an adenocarcinoma of the ampulla of Vater in a 54-year-old woman with NF-1 admitted to the hospital with jaundice and undergoing pancreato-duodenectomy. Histologically, the resected specimen showed an adenocarcinoma of the ampulla as being a part of a complex atypical epithelial proliferation extended from the papilla to the mucosa of the duodenum and distal choledochus, islet-cell adenomatosis of the pancreas and multiple gastric, duodenal, jejunal stromal tumors. The ampullary and periampullary adenocarcinomas in NF-1 patients have peculiar features, suggesting a widespread predisposition to cancer development in periampullary tissues and requiring widely demolitive surgery. Moreover, they occur at a younger age than those occurring in non-NF-1 patients, may be associated with additional periampullary epithelial tumors, are often operable and may present long survival.

[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.

Genetically engineered mouse models of astrocytoma: GEMs in the rough?

Astrocytomas are the most common form of brain cancer and are essentially incurable due to their diffusely infiltrative nature. Mouse models of astrocytoma provide a useful system for understanding tumorigenesis of astrocytomas and for designing and testing new therapies. Although molecular genetic alterations have been characterized in human astrocytomas, many of the mice engineered with these mutations do not develop astrocytomas. Recently, successful modeling of astrocytoma in the mouse has suggested that the combination of molecular alterations, the cell type in which the alterations take place, and the strain background all play a role in generating a model of astrocytoma.

Therapy-related leukemia associated with alkylating agents

The leukemogenic potential of alkylating agents has been known for many years and almost all alkylating agents in clinical use have been shown to increase the risk of leukemia. With these drugs the risk of leukemia appears to increase with increasing patient age, as does the risk of de novo myeloid leukemia in the population. Susceptibility to alkylating agent-associated leukemia is influenced by the genetic constitution of the patient, and by the nature of the exposure. To illustrate the importance of these factors in etiology of leukemia, this paper discusses the contribution of disorders such as Fanconi anemia and neurofibromatosis to susceptibility to alkylating agent-associated leukemia. This paper also discusses the contribution of alkylating agents and other therapeutic exposures in the etiology of leukemias occurring after autologous bone marrow transplant.

Mortality in neurofibromatosis 1: an analysis using U.S. death certificates

Although neurofibromatosis 1 (NF1) is a relatively common autosomal dominant condition, information about its effect on mortality is limited. We used Multiple-Cause Mortality Files, compiled from U.S. death certificates by the National Center for Health Statistics, for 1983 through 1997. We identified 3,770 cases of presumed NF1 among 32,722,122 deaths in the United States, a frequency of 1/8,700, which is one-third to one-half the estimated prevalence. Mean and median ages at death for persons with NF1 were 54.4 and 59 years, respectively, compared with 70.1 and 74 years in the general population. Results of proportionate mortality ratio (PMR) analyses showed that persons with NF1 were 34 times more likely (PMR=34.3, 95% confidence interval [CI] 30.8-38.0) to have a malignant connective or other soft-tissue neoplasm listed on their death certificates than were persons without NF1. Overall, persons with NF1 were 1.2 times more likely than expected (PMR=1.21, 95% CI 1.14-1.28) to have a malignant neoplasm listed on their death certificates, but the PMR was 6.07 (95% CI 4.88-7.45) for persons who died at 10-19 years of age and was 4.93 (95% CI 4.14-5.82) for those who died at 20-29 years of age. Similarly, vascular disease was recorded more often than expected on death certificates of persons with NF1 who died at <30 years of age (PMR=3.26, 95% CI 1.31-6.71 at age <10 years; PMR=2.68, 95% CI 1.38-4.68 at age 10-19 years; and PMR=2.25, 95% CI 1.46-3.32 at 20-29 years) but not in older persons. This study supports previous findings of decreased life expectancy for persons with NF1 and, within the limitations of death certificates, provides population-based data about NF1 morbidity and mortality that are useful to clinicians caring for patients with NF1.

Malignancy in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) represents a major risk factor for development of malignancy, particularly malignant peripheral nerve sheath tumors (MPNST), optic gliomas, other gliomas, and leukemias. The oncologist will see NF1 patients referred for treatment of malignancy, and should be alert to the possibility of undiagnosed NF1 among patients with cancer. Brain tumors tend to have a more indolent course in NF1 than in the general population, and hence are best managed conservatively. MPNST, in contrast, do not respond to standard chemotherapy or radiation therapy. The most effective treatment of MPNST appears to be early diagnosis and surgery, but early diagnosis is hampered by frequent occurrence within preexisting large tumors, making new growth or change difficult to detect. New insights into pathogenesis now offer hope of development of specific methods of treatment with reduced toxicity and more precise molecular targeting. There is an urgent need, however, to develop methods to measure tumor growth and monitor outcomes, develop preclinical drug screening systems, and further explore the pathogenesis of the disorder to determine whether mechanisms other than Ras regulation may be important in pathogenesis.

Neoplasms in neurofibromatosis 1 are related to gender but not to family history of cancer

The risk of malignancies among persons with neurofibromatosis 1 (NF1) is higher than in the general population, but the excess risk has not been precisely estimated. The effects of gender and inheritance pattern on cancer risk are unclear. Therefore, we conducted a historical cohort study to determine cancer risk factors by contacting 138 Caucasian NF1 patients originally seen at Baylor College of Medicine (BCM) in Houston between 1978 and 1984. A total of 304 patients of all ethnic groups were evaluated at BCM during this period. We successfully located 173 patients, 138 of who were Caucasian. We computed standardized incidence ratios (SIRs) with the age-, gender-, and time period-specific rates from the Connecticut Tumor Registry for 2,094 person-years of observation (median follow-up = 16 years). Eleven incident tumors were reported. Females were at much higher risk of cancer than males (SIR = 5.6, 95% confidence interval (CI) 2.7-10.3 and SIR = 0.6; 95% CI, 0.0-3.0, respectively). We found no elevated cancer risk in unaffected first-degree relatives, regardless of whether the proband had cancer or not (SIR = 1.1 95% CI, 0.6-1.8 and SIR = 1.0, 95% CI, 0.6-1.5, respectively). Our results suggest that malignancy in the proband is not the result of a modifying gene that has a significant impact on general cancer risk.

Neuro-ophthalmology of the phacomatoses

The phacomatoses are a group of disorders that feature multiple hamartomas of the central and peripheral nervous system, eye, skin, and viscera. Most of these disorders have a well-defined Mendelian pattern of inheritance because of a mutation in a single gene which has been identified. In other instances, no clear patterns of inheritance or genetic susceptibility have been recognized. The combination of ocular and central nervous system manifestations in patients with phacomatoses makes neuro-ophthalmologic evaluation particularly important in diagnosis and management. This review provides an overview of the phacomatoses with emphasis on recent reports of significance to neuro-ophthalmology.

Nf1;Trp53 mutant mice develop glioblastoma with evidence of strain-specific effects

Astrocytomas are the leading cause of brain cancer in humans. Because these tumours are highly infiltrative, current treatments that rely on targeting the tumour mass are often ineffective. A mouse model for astrocytoma would be a powerful tool for dissecting tumour progression and testing therapeutics. Mouse models of astrocytoma have been designed to express oncogenic proteins in astrocytes, but have had limited success due to low tumour penetrance or limited tumour progression. We present here a mouse model of astrocytomas involving mutation of two tumour-suppressor genes, Nf1 and Trp53. Humans with mutations in NF1 develop neurofibromatosis type I (NF1) and have increased risk of optic gliomas, astrocytomas and glioblastomas. The TP53 tumour suppressor is often mutated in a subset of astrocytomas that develop at a young age and progress slowly to glioblastoma (termed secondary glioblastomas, in contrast to primary glioblastomas that develop rapidly de novo). This mouse model shows a range of astrocytoma stages, from low-grade astrocytoma to glioblastoma multiforme, and may accurately model human secondary glioblastoma involving TP53 loss. This is the first reported mouse model of astrocytoma initiated by loss of tumour suppressors, rather than overexpression of transgenic oncogenes.