Gastrointestinal and retroperitoneal manifestations of type 1 neurofibromatosis

Isolated Rectal Neurofibroma: A Case Report and Literature Review

Neurofibromas are considered benign peripheral nerve sheath tumors containing Schwann cells, fibroblasts, and perineurial cells. They are commonly associated with familial disorders. Isolated colonic neurofibromas are very rare. In this report, we discuss a case of a patient who presented to the gastroenterology clinic with a week-long occurrence of abdominal pain and bleeding. She underwent a colonoscopy in which three sentinel polyps of benign appearance, ranging in size from 4 mm to 10 mm, were removed during the procedure. The pathology report indicated that the distal rectal polyp contained a submucosal neurofibroma with SOX10+, desmin-, CD117-, DOG1-, CD34+. While NF1-associated neurofibromas harbor the risk of malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs), the malignancy potential for isolated colonic neurofibromas remains uncertain due to their rarity. The clinical significance of isolated colonic neurofibromas is yet to be defined; therefore, the optimal management strategy remains uncertain. Close monitoring is advocated to both exclude the possibility of neurofibromatosis and be vigilant about the risk of malignant transformation.

Discovery of A Polymorphic Gene Fusion via Bottom-Up Chimeric RNA Prediction

Gene fusions and their chimeric products are typically considered hallmarks of cancer. However, recent studies have found chimeric transcripts in non-cancer tissues and cell lines. In addition, efforts to annotate structural variation at large scale have found examples of gene fusions with potential to produce chimeric transcripts in normal tissues. In this report, we provide a means for targeting population-specific chimeric RNAs to enrich for those generated by gene fusion events. We identify 57 such chimeric RNAs from the GTEx cohort, including SUZ12P1-CRLF3 and TFG-ADGRG7 , whose distribution we assessed across the populations of the 1000 Genomes Project. We reveal that SUZ12P1-CRLF3 results from a common complex structural variant in populations with African heritage, and identify its likely mechanism for formation. Additionally, we utilize a large cohort of clinical samples to characterize the SUZ12P1-CRLF3 chimeric RNA, and find an association between the variant and indications of Neurofibramatosis Type I. We present this gene fusion as a case study for identifying hard-to-find and potentially functional structural variants by selecting for those which produce population-specific fusion transcripts.

KEY POINTS

- Discovery of 57 polymorphic chimeric RNAs- Characterization of SUZ12P1-CRLF3 polymorphic chimeric RNA and corresponding rearrangement- Novel bottom-up approach to identify structural variants which produce transcribed gene fusions.

MULTIPLE NEUROENDOCRINE NEOPLASIA IN A PATIENT WITH TYPE I NEUROFIBROMATOSIS (NF1): REPORT OF A NEW MUTATION (NF1, EXONS 2-30 DELETION) AND LITERATURE REVIEW

BACKGROUND

Plexiform neurofibromas represent a common neoplasia of type 1 neurofibromatosis in which neurofibromas arise from multiple nerves involving connective tissue and skin and rarely affect the colon and rectum. Co-occurrence of plexiform neurofibromas, neuroendocrine tumors with primary involvement of the rectum, and medullary thyroid carcinoma in patients with neurofibromatosis type 1 is a previously undescribed condition. The aim of this manuscript was to present a case of primary plexiform neurofibroma and neuroendocrine tumors of the upper rectum in a patient with neurofibromatosis type 1 whose genetic sequencing found a novel mutation in the neurofibromatosis type 1 gene and to review the literature.

CASE REPORT

A 49-year-old woman with a familial history of neurofibromatosis type 1 complained of abdominal cramps for 6 months. She had previously been submitted for a total thyroidectomy due to medullary thyroid carcinoma. She was submitted to a colonoscopy, which identified a submucosa lesion located in the upper rectum. The patient was referred for a laparoscopic rectosigmoidectomy, and the histopathological study of the surgical specimen identified two different tumors. An immunohistochemical panel was done for histopathological confirmation of the etiology of both lesions. The results of the panel showed intense immunoexpression of S100 protein in the largest and superficial lesion, as well as positivity for chromogranin and synaptophysin in the minor and deep lesion confirming the diagnosis of rectal plexiform neurofibromas concomitant with neuroendocrine tumors. The proliferative activity rate using Ki-67 antibodies showed that both tumors had a low rate of mitotic activity (<1%). Genetic sequence panel identified an undescribed mutation in the neurofibromatosis type 1 gene (deletion, exons 2-30). The patient's postoperative evolution was uneventful, and she remains well, without recurrence, 3 years after surgery.

CONCLUSION

The co-occurrence of medullary thyroid carcinoma, plexiform neurofibromas, and neuroendocrine tumors of the rectum in patients with neurofibromatosis type 1 is an exceptional and undescribed possibility, whose diagnosis can be confirmed by the immunohistochemical staining and genetic panel.

Reminder for the clinician: abdominal manifestations of type 1 neurofibromatosis are not so uncommon

We describe the case of a woman in her 50s with abdominal pelvic masses suspected to be an ovarian lesion with metastases. At laparoscopy, it appeared as a possible abdominal location of neurofibromatosis type 1 (NF-1). A 50 cm of small bowel was resected to remove multiple nodular lesions. On histopathology, small bowel lesions (n=14) were all classified as GISTs. Clinicians should recognise and consider gastrointestinal manifestations of NF-1 in the diagnostic flow chart. Surgical treatment may resolve symptomatic cases and prevent local infiltration or malignant degeneration of abdominal neoplasms occurring in patients with NF-1.

Challenges in the management of metastatic gastrointestinal stromal tumor in a patient with neurofibromatosis type 1: a case report

BACKGROUND

Neurofibromatosis type 1 is an inherited cancer predisposition syndrome that is caused by a mutation in the NF1 gene that encodes neurofibromin. Patients with neurofibromatosis type 1 have a higher risk of gastrointestinal stromal tumor. This study reports the case of a patient with gastrointestinal stromal tumor who was later diagnosed to have neurofibromatosis type 1 and, unlike usual features, had some uncommon features such as occurrence at an early age and unusual site of origin.

CASE

We report the case of a 29-year-old Indian female diagnosed to have gastrointestinal stromal tumor originating from the greater curvature of the stomach. Gastrointestinal stromal tumor was wild type, negative for c-kit and platelet-derived growth factor receptor, and had an aggressive clinical course not responding to oral tyrosine kinase inhibitors. On later evaluation, we found that the patient had germline mutation in NF1. This case has some unusual features compared with gastrointestinal stromal tumor cases reported in neurofibromatosis type 1. Firstly, the age of onset for gastrointestinal stromal tumor in neurofibromatosis type 1 is earlier in our case compared with previous cases reported in literature. Secondly, the site of occurrence is in the stomach, without involving other parts of the intestine. Gastrointestinal stromal tumor in neurofibromatosis type 1 is usually multifocal, and small intestine is the common site of occurrence. When occurring in the stomach, it is usually associated with other lesions in the small intestine. Lastly, the clinical course is aggressive compared with previous case reports and series.

CONCLUSION

Our patient had germline NF1 mutation and cutaneous stigmata of neurofibromatosis. Our patient had unicentric gastrointestinal stromal tumor occurring at younger age and involving greater curvature of the stomach, with spindle cell type histology and high-risk features. If gastrointestinal stromal tumor occurs at young age, we should look into neurocutaneous markers.

Giant composite pheochromocytoma and gastrointestinal stromal tumor in a patient with neurofibromatosis: A case report

A 54-year-old male was admitted to our department with neurofibromatosis and hypertension. During his examination, a mass was detected in the abdomen, and he was transferred to a surgical clinic. At the first examination of the patient, extensive café-au-lait spots and granulomas were detected on the body and the mass occupying right abdomen quadrant was palpable. The patient’s medical history indicated that he had hypertension for almost a decade. The patient also stated that nodules on the body existed from his earliest recollection and he had relatives with neurofibromatosis. The patient was taken to a surgical operation. A mass with 30×23 cm in size was removed. The area of the nodular structure, with 0.5 cm in diameter, in the stomach serosa was also removed. The tumor was composed of phaeochromocytoma in the larger spaces and ganglioneuromas in the relatively narrow spaces. The nodular area removed in gastric serosa was reported as a very low-risk gastrointestinal stromal tumor. Apart from this rare combination, adrenal mass removed from the patient was considerably larger than the masses in the literature until now. Therefore, we aimed to present this rare case with a literature background.

A case of appendiceal ganglioneuroma in neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 is an autosomal dominant inherited disease associated with multiple skin neurofibromas or other neurogenic tumors, such as nodular plexiform neurinoma or cerebrospinal tumor. Gastrointestinal stromal tumors are often complicated in patients with neurofibromatosis type 1, although involvement of the appendix is rare, and there have been few reports of appendiceal ganglioneuroma.

CASE PRESENTATION

The patient was a 29-year-old man diagnosed with neurofibromatosis type 1 based on physical findings and his family history. During the follow-up of neurofibromatosis, computed tomography was performed to detect neurological tumors, such as neurofibromas in the brain, spinal cord, and gastrointestinal tract. Computed tomography showed a markedly thickened appendix wall, and an appendiceal tumor was suspected. Laparoscopic appendectomy was performed, and a 50 × 35 mm appendiceal submucosal tumor was resected with a negative resection margin. At histopathological examination, the tumor was diagnosed as ganglioneuroma; it showed short spindle-shaped cells and ganglion cells diffusely infiltrated into the proper muscle layer and fibrous tissue that grew around nerve cells. The patient was discharged on the 5th postoperative day without postoperative complications and was doing well at 13 months following the operation.

CONCLUSIONS

Gastrointestinal stromal tumor and neurofibroma are the most common gastrointestinal tumors associated with neurofibromatosis type 1, but ganglioneuroma of the appendix is rare. Appendiceal neurogenic tumors should be considered in patients with neurofibromatosis type 1, and surgical resection is necessary because of the risk of malignancy.

Epidemiology of neuroendocrine tumors of the appendix in the USA: a population-based national study (2014-2019)

Background

The appendix is the third most common place for neuroendocrine tumors (NETs) along the digestive tract and NETs are the most common neoplasms of the appendix. However, there are limited population-based data on the epidemiology of this disease. Using a large database, we sought to describe the epidemiology and risk association of NETs of the appendix.

Method

We queried a multi-institutional database (Explorys Inc., Cleveland, OH, USA), comprising 360 hospitals in the United States (US), for patients with a diagnosis of NETs of the appendix from 2014-2019.

Results

Of the 30,324,050 individuals in the database, 2020 patients had an appendiceal NET diagnosis (0.007%). The most common presenting symptoms included abdominal pain, nausea, vomiting and diarrhea. Patients with appendiceal NETs were more likely to be female (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.24-1.49), Caucasian (OR 2.71, 95%CI 2.40-3.07), with a history of smoking (OR 1.82, 95%CI 1.65-2.01), family history of primary gastrointestinal malignancy (OR 7.26, 95%CI 6.31-8.33), diagnosis of multiple endocrine tumor type 1 (OR 52.31, 95%CI 23.15-118.23), or neurofibromatosis type 1 (OR 16.37, 95%CI 7.24-37.01).

Conclusions

In a population-based study in the US, using the Explorys database, we found the overall prevalence of NETs of the appendix to be 7 per 100,000 persons. The incidence in the year January 2019-January 2020 was 0.4 per 100,000 individuals. These rates are higher than previously reported and may be more accurate, given the more comprehensive nature of the Explorys database.

Comprehensive clinicopathologic characteristics of intraabdominal neurogenic tumors: Single institution experience

BACKGROUND

Neurogenic tumors are rare but represent an important consideration in the differential diagnosis of abdominal mesenchymal tumors. Reports on their incidence, pathological features and clinical characteristics are scarce.

AIM

To advance the overall knowledge on the histologic, immunohistochemical, clinical and radiologic characteristics of neurogenic tumors through this case series.

METHODS

An established database of a nationwide tertiary referral center, covering a 15-year period (2005 and 2020), was retrospectively re-evaluated. Diagnoses of neurogenic tumor cases were confirmed by two experts following review of the macroscopic, histological and immunohistochemical records along with findings from analysis of archived tissue sections for each included patient. Tissue microarrays were constructed for cases lacking necessary immunohistochemical studies. Clinical data and follow-up information were collected from the hospital records and the patients themselves, when available.

RESULTS

The study included 19 cases of intraabdominal neurogenic tumors, representing 12 women and 7 men, between 18 and 86 years of age (median: 51 years). Final confirmed diagnoses were 12 schwannomas, 2 diffuse submucosal neuro-fibromatoses, 2 ganglioneuromas, 2 malignant peripheral sheath nerve tumors, and 1 mucosal Schwann cell hamartoma. Sizes of the tumors were variable, with a median diameter of 4 cm; the two largest (> 10 cm) were schwannomas. The majority of cases were asymptomatic at presentation, but the most frequent symptom was abdominal pain. Gastrointestinal tract lesions were detected with endoscopy and extra-luminal lesions were detected with cross-sectional imaging. All cases were S100-positive and CD117-negative; most cases were negative for desmin, epithelial membrane antigen, smooth muscle actin and CD34. In all but 5 cases, the Ki67 proliferation index was ≤ 1%.

CONCLUSION

Re-evaluation of 19 cases of abdominal neurogenic tumors demonstrated con-siderable variability in clinicopathologic characteristics depending on location, dimension and histological features.

Imaging Features of Neurofibromatosis Type 1 in the Abdomen and Pelvis

OBJECTIVE. Loss of the neurofibromatosis type 1 (NF1) tumor suppressor protein causes uninhibited activation of the RAS oncogene, which leads to tumorigenesis in patients with NF1. This case-based review discusses imaging manifestations of NF1 in the abdomen and pelvis, highlighting key genetic associations and management to elucidate features different from the general population. CONCLUSION. The spectrum of pathologic findings includes gastrointestinal tumors such as gastrointestinal stromal tumors, genitourinary lesions including urogenital neurofibromas, vascular entities such as renal artery stenosis, and less common associations like lymphoma.

Abdominal neoplastic manifestations of neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is an autosomal dominant hereditary tumor syndrome, with a wide clinicopathologic spectrum. It is defined by characteristic central nervous system, cutaneous and osseous manifestations, and by mutations in the NF1 gene, which is involved in proliferation via p21, RAS, and MAP kinase pathways. Up to 25% of NF1 patients develop intra-abdominal neoplastic manifestations including neurogenic (commonly plexiform neurofibromas and malignant peripheral nerve sheath tumors), interstitial cells of Cajal (hyperplasia, gastrointestinal stromal tumors), neuroendocrine, and embryonal tumors (rhabdomyosarcoma). Nonspecific symptoms, multifocal disease, or coexistence of 2 or more tumor types make patients challenging to diagnose and manage. Screening for intra-abdominal tumors in NF1 patients remains controversial, and currently no guidelines are established. Management decisions are complex and often informed by single-center experiences or case studies in the literature, though the field is rapidly evolving. Thus, NF1 patients should be followed in specialist centers familiar with their wide spectrum of pathology and with multidisciplinary care including specialized pathology and radiology. This review will (1) provide a contemporaneous synthesis of the literature and our multi-institutional clinical experiences with intra-abdominal neoplasms in NF1 patients, (2) present a classification framework for this heterogeneous group of disorders, and (3) outline approaches to screening, surveillance, diagnosis, and management.

Isolated colonic neurofibroma, a rare tumor: A case report and review of literature

BACKGROUND

Neurofibromas are tumors comprised of peripheral nerve sheath and connective tissue components. They can occur sporadically or as part of familial syndromes such as neurofibromatosis type 1. Isolated colonic neurofibroma without systemic manifestations is a rarely reported clinical entity. Here we present a case of a 51 years old male with an isolated colonic neurofibroma seen on a screening colonoscopy.

CASE SUMMARY

Fifty-one years old male who was otherwise healthy without a significant family history of cancer underwent a screening colonoscopy and was found have a 2.3 cm × 1.4 cm lesion in the colon. Tissue biopsy revealed a spindle cell tumor. Magnetic resonance imaging of the pelvis was negative for adenopathy. He underwent an endoscopic ultrasound that showed an ill-defined avascular lesion of mixed echogenicity measuring 2.8 cm × 15.2 cm in the submucosa with no communication with muscularis mucosa or propria. Immunohistochemistry staining of the tumor was strongly positive for S100, with rare penetrating axons deep within the tumor. Tumor cells were negative for c-kit and desmin and had low Ki-67 index. These findings were consistent with a solitary colonic submucosal neurofibroma. A detailed history and physical examination did not reveal any evidence of extraintestinal neurofibromatosis. He underwent transanal surgical resection of the tumor. The patient tolerated the procedure well without any complications.

CONCLUSION

While neurofibromas have been well described in literature, an isolated colonic neurofibroma is a rare pathological entity. Malignant transformation of neurofibromas has been reported in patients with neurofibromatosis syndromes. We report a case of isolated colonic neurofibroma and highlight the importance of resection due to the increased risk of tumorigenesis.

Neurofibromatosis 1 French national guidelines based on an extensive literature review since 1966

Neurofibromatosis type 1 is a relatively common genetic disease, with a prevalence ranging between 1/3000 and 1/6000 people worldwide. The disease affects multiple systems with cutaneous, neurologic, and orthopedic as major manifestations which lead to significant morbidity or mortality. Indeed, NF1 patients are at an increased risk of malignancy and have a life expectancy about 10-15 years shorter than the general population. The mainstay of management of NF1 is a patient-centered longitudinal care with age-specific monitoring of clinical manifestations, aiming at the early recognition and symptomatic treatment of complications as they occur. Protocole national de diagnostic et de soins (PNDS) are mandatory French clinical practice guidelines for rare diseases required by the French national plan for rare diseases. Their purpose is to provide health care professionals with guidance regarding the optimal diagnostic and therapeutic management of patients affected with a rare disease; and thus, harmonizing their management nationwide. PNDS are usually developed through a critical literature review and a multidisciplinary expert consensus. The purpose of this article is to present the French guidelines on NF1, making them even more available to the international medical community. We further dwelled on the emerging new evidence that might have therapeutic potential or a strong impact on NF1 management in the coming feature. Given the complexity of the disease, the management of children and adults with NF1 entails the full complement healthcare providers and communication among the various specialties.

Recurrent gastrointestinal bleeding in a patient with type 1 neurofibromatosis

Type 1 neurofibromatosis (NF1) is a hereditary disorder with an incidence of approximately 1:3000 at birth. Gastrointestinal (GI) lesions occur in approximately one-third of the patients, with most being asymptomatic and diagnosed incidentally. Symptomatic lesions leading to GI bleeding are uncommon. We share our experience of an elderly man with NF1, who presented with massive recurrent GI bleeding secondary to jejunal neurofibromas. The lesions were identified on CT scan of abdomen, and the patient was managed with resection of the involved bowel segment.

A case report of hamartomatous polyposis in an individual with Neurofibromatosis type 1

Even in well-described genetic syndromes, such as neurofibromatosis type 1, expansion of the phenotype should be considered as a possible explanation for atypical presentations. However, it is critical to complete the evaluation for a potential dual diagnosis, as there could be significant prognostic and management implications.

Spectrum of gastrointestinal lesions of neurofibromatosis type 1: a pictorial review

Abstract

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. Gastrointestinal manifestations of NF-1 are seldom thought of in routine clinical practice and might thus be significantly under-recognised. Their heterogeneous spectrum ranges from localised microscopic proliferative lesions to grossly recognizable mass-forming neurofibromas, neuroendocrine and gastrointestinal stromal tumours (GIST). The aim of this study is discussing the imaging evaluation and characterisation of the abdomen lesions in patients with NF1.

Teaching Points

• Neurofibromatosis type (NF-1) is one of the most common single gene disorders.

• Every organ system can be involved and intra-abdominal manifestations are underestimated.

• The NF1 abdominal manifestations comprehend five categories of tumours.

• Neurogenic tumours including with neurofibromas are the most common type.

• Early diagnosis of abdominal manifestations of NF-1 based on imaging patterns is necessary for appropriate treatment to avoid serious organic complications related to tumour mass.

Neural and neurogenic tumours of the gastroenteropancreaticobiliary tract

Neural lesions occur uncommonly in the gastroenteropancreaticobiliary tract. However, due to the growing number of screening colonoscopy procedures, polypoid neural lesions of the colon are being recognised increasingly and range from benign tumours to high-grade malignant neoplasms. Morphological variability of neural tumours can be wide, although some entities share pathological features, and, as such, these lesions can be diagnostically challenging. We review the spectrum of pathology of neural tumours in the gastroenteropancreaticobiliary tract, with the goal of providing a practical approach for practising surgical pathologists.

Intraductal papillary bile duct adenocarcinoma and gastrointestinal stromal tumor in a case of neurofibromatosis type 1

We report our experience with a synchronous case of gastrointestinal stromal tumor (GIST) and intraductal papillary neoplasm of the bile duct (IPNB) in an elderly woman with neurofibromatosis type 1 (NF-1). A 72-year-old woman presented with a 2-mo history of right upper abdominal pain unrelated to diet and indigestion. Fourteen years earlier, she had been diagnosed with NF-1, which manifested as café au lait spots and multiple nodules on the skin. Computed tomography (CT) revealed a multilocular low-density mass with septation, and mural nodules in the right hepatic lobe, as well as a 1.7-cm-sized well-demarcated enhancing mass in the third portion of the duodenum. The patient subsequently underwent right hepatectomy and duodenal wedge resection. We present here the first report of a case involving a synchronous IPNB and GIST in a patient with NF-1. Our findings demonstrate the possibility of various tumors in NF-1 patients and the importance of diagnosis at an early stage

Genetic and epigenetic drivers of neuroendocrine tumours (NET)

Neuroendocrine tumours (NET) of the gastrointestinal tract and the lung are a rare and heterogeneous group of tumours. The molecular characterization and the clinical classification of these tumours have been evolving slowly and show differences according to organs of origin. Novel technologies such as next-generation sequencing revealed new molecular aspects of NET over the last years. Notably, whole-exome/genome sequencing (WES/WGS) approaches underlined the very low mutation rate of well-differentiated NET of all organs compared to other malignancies, while the engagement of epigenetic changes in driving NET evolution is emerging. Indeed, mutations in genes encoding for proteins directly involved in chromatin remodelling, such as DAXX and ATRX are a frequent event in NET. Epigenetic changes are reversible and targetable; therefore, an attractive target for treatment. The discovery of the mechanisms underlying the epigenetic changes and the implication on gene and miRNA expression in the different subgroups of NET may represent a crucial change in the diagnosis of this disease, reveal new therapy targets and identify predictive markers. Molecular profiles derived from omics data including DNA mutation, methylation, gene and miRNA expression have already shown promising results in distinguishing clinically and molecularly different subtypes of NET. In this review, we recapitulate the major genetic and epigenetic characteristics of pancreatic, lung and small intestinal NET and the affected pathways. We also discuss potential epigenetic mechanisms leading to NET development.

Imaging of secretory tumors of the gastrointestinal tract

Gastrointestinal secretory tumors, or gastroenteropancreatic neuroendocrine tumors, encompass a wide array of endocrine cell tumors. The significance of these tumors lies in their ability to alter physiology through hormone production as we well as in their malignant potential. Functioning tumors may present earlier due to symptomatology; conversely, non-functioning tumors are often diagnosed late as they reach large sizes, causing symptoms secondary to local mass effect. Imaging aids in the diagnosis, staging, and prognosis and provides key information for presurgical planning. Although most of these tumors are sporadic, some are associated with important syndromes and associations, knowledge of which is critical for patient management. In this article, we provide an overview of secretory and neuroendocrine tumors of the GI tract and pancreas.

Coexistence of Juvenile-Like Polyp with Neurofibroma at the Gastroesophageal Junction in an Adult with Neurofibromatosis Type I

A 23-year-old Caucasian male with Neurofibromatosis Type I (NF-I) was found to have a submucosal nodule at the gastroesophageal junction (GEJ) and underwent endoscopic submucosal dissection. Histological examination revealed two different lesions within the nodule. The dominant lesion was inflammatory/hyperplastic (juvenile-like) polyp with obliterative vasculopathy while the smaller lesion was a neurofibroma. Gastric/GEJ lesions in NF-I are very rare with only seven cases reported in the literature. Three cases of juvenile-like gastric polyps (located in the antrum, greater curvature, and fundus) have been reported in adult NF-I patients. An inflammatory polyp associated with a neurofibroma has only been described once in the pediatric literature but never in an adult. Our case is unique from those previously described in the literature due to the age of the patient, the presence of 2 histologically separate lesions in one endoscopically evident lesion, and the presence of obliterative vasculopathy in the juvenile-like polyp.

A case of periampullary adenocarcinoma in neurofibromatosis type 1

Neurofibromatosis type 1 (NF-1) is an autosomal dominant genetic disorder with a known predisposition to gastrointestinal neoplasms such as stromal tumors and carcinoids. Adenocarcinomas (ACs) of the gastrointestinal tract are relatively rare in patients with NF-1, especially those found in the periampullary region. We present a case report of periampullary adenocarcinoma in a 56-year-old woman with NF-1 who presented with abdominal pain and obstructive jaundice.

Intestinal obstruction in von Recklinghausen's disease

AIM

Gastrointestinal manifestations occur in up to 25% of patients with neurofibromatosis type 1. This review reports all published cases of acute intestinal obstruction due to neurofibromatosis type 1 and identifies mechanisms of obstruction, the nature of the tumour and the outcome.

METHOD

A systematic review of the literature on acute intestinal obstruction due to neurofibromatosis type 1 was performed by searching the major electronic databases. All relevant references were reviewed for possible inclusion. All the references of the relevant articles were screened for any further articles that were missed in the initial search.

RESULTS

We identified 25 articles from 1972 to 2013 reporting 25 patients with von Recklinghausen's disease who underwent laparotomy for acute intestinal obstruction. Three further patients were operated on in our institution. The mean age of the patients was 44.2 years and the male/female ratio 15/13. The mechanisms of obstruction were intrinsic obstruction (16), extrinsic obstruction (8) and intussusception (4). Histology was reported to show neurofibroma (19), gastrointestinal stromal tumour (5) and adenocarcinoma (4). Among patients whose outcome was mentioned (17), 10 were asymptomatic after a mean follow-up of 1.5 years.

CONCLUSION

Acute bowel obstruction is a rare manifestation of neurofibromatosis type 1. Surgery is often necessary to treat the complication and to determine the exact nature of the tumour and the prognosis.

Neurofibromatosis type 1: a multidisciplinary approach to care

Neurofibromatosis type 1 is a relatively common inherited disorder. Patients have a high predisposition to develop both benign and malignant tumours. Although many manifestations of neurofibromatosis type 1 affect the nervous system, other organs and tissues can also be affected. Because of the varying features and clinical heterogeneity inherent to this disorder, patients can present to different medical and surgical specialists and, therefore, the association of clinical symptoms with neurofibromatosis type 1 might not be appreciated. Thus, for prompt diagnosis and to provide optimum care for patients with neurofibromatosis type 1, clinicians must be aware of the diverse clinical features of this disorder. We advocate a multidisciplinary approach to care, entailing a dedicated team of specialists throughout the lifetime of the patient. As our understanding of this disorder deepens through basic laboratory and clinical investigations, swift implementation of new effective treatments becomes feasible.

Severe Hypercholesterolemia: A Unique Presentation of Non-Hodgkin's Lymphoma in a Patient with Neurofibromatosis Type 1

We report a case of non-Hodgkin's lymphoma (NHL) with an unusual initial manifestation as severe hypercholesterolemia and obstructive jaundice in a patient with neurofibromatosis type 1 (NF 1). NHL should be considered in the evaluation of obstructive jaundice alone or in combination with severe hypercholesterolemia. Relief of biliary obstruction led to the resolution of hypercholesterolemia in our 59-year-old male patient, followed by doxorubicin-based chemotherapy for the underlying lymphoma. NF 1 is a genetic condition that results from a defect in a tumor-suppressor gene and it is likely that this led to the development of NHL in our patient. It is important that clinicians are familiar with the gastrointestinal manifestations of NF 1, especially its association with intra-abdominal malignancies, when treating patients with a personal or family history. To the best of our knowledge, this is the first case of NHL presenting initially as severe hypercholesterolemia and it is also one of the few instances where NHL has been reported in association with NF 1.

Small bowel volvulus as a complication of von Recklinghausen’s disease: A case report

We report the case of a 25-year-old male with Neurofibromatosis type I (NF-1), who presented at the time of admission with clinical findings of an acute abdomen caused by a mechanical obstruction. Computerized tomography showed a volvulus of the terminal ileum with mesenteric swirling as the cause of the patient’s symptoms. Consecutive exploratory laparotomy confirmed the diagnosis and 70 cm of the small intestine was resected due to an affection of the mesentery by multiple neurofibromas. The gastrointestinal tract is affected in approximately 10% of patients with NF-1, however the mesentery is almost always spared. Here we describe the unique case of a patient with a volvulus caused by mesenteric manifestation of von Recklinghausen’s disease, emphasizing the role of surgery in a team of multidisciplinary specialists to treat this multiorganic disease.

Coexistence of gastrointestinal stromal tumors (GISTs) and pheochromocytoma in three cases of neurofibromatosis type 1 (NF1) with a review of the literature

It is well known that neurofibromatosis type 1 (NF1) is uncommonly associated with pheochromocytoma development and also, to a larger extent, with gastrointestinal stromal tumors (GISTs). We herein document three cases with the rare condition of NF1 coexisting with GIST and pheochromocytoma, while one of them also has a composite tumor and another has papillary thyroid carcinoma.

Genetics of neuroendocrine tumours, hereditary tumour syndromes

Neuroendocrine tumours occur in some hereditary tumour syndromes, and the molecular pathophysiological mechanisms involved in these are also important in their sporadic counterparts which representing the majority of neuroendocrine tumours. These syndromes include multiple endocrine neoplasia type 1, von Hippel–Lindau syndrome, neurofibromatosis type 1 and tuberous sclerosis. All these follow an autosomal dominant inheritance. The primarily affected molecular pathways are Ras-MAPK signalling, hypoxia induced factor 1α, and mTOR signalling that are also involved in sporadic tumours and may even represent potential molecular targets of therapy. In this review, the major characteristics of hereditary tumour syndromes, their molecular genetics and the pathophysiological mechanisms involved in sporadic tumours are discussed. Orv. Hetil., 2013, 154, 1541–1548.

Abdominal manifestations of neurologic disorders

A variety of disorders-including infectious, inflammatory, hereditary, and metabolic diseases-may affect both the brain and abdominal cavity, and the findings in one region may help establish the diagnosis or limit the differential diagnosis. Establishing an accurate early diagnosis enables clinicians to adequately manage these unusual diseases and potentially avert life-threatening complications. For example, an early diagnosis of Gardner syndrome enables annual sigmoid- or colonoscopy and ultrasonography. In many conditions, abdominal manifestations precede neurologic manifestations and may have prognostic significance. Patients with celiac disease more often present with abdominal manifestations such as duodenitis, slow transit time, reversal of the jejunal-ileal fold pattern, and transient small bowel intussusception than with intracranial manifestations. In other conditions, the neurologic manifestations may be the same as the presenting symptoms. For example, patients with Gardner syndrome may initially present with multiple mandibular or sinonasal osteomas. In addition, sarcoidosis may manifest with multifocal enhancing dural masses. Abdominal and neurologic manifestations may even occur simultaneously, as in several of the phakomatoses such as neurofibromatosis type 1, tuberous sclerosis complex, and von Hippel-Lindau syndrome. Ultimately, familiarity with the appearances of these conditions allows radiologists to pinpoint a diagnosis, even when imaging findings in either location are nonspecific.

Neoplasms associated with germline and somatic NF1 gene mutations

INTRODUCTION

Neurofibromatosis 1 is a tumor predisposition genetic syndrome with autosomal dominant inheritance and virtually 100% penetrance by the age of 5 years. NF1 results from a loss-of-function mutation in the NF1 gene, resulting in decreased levels of neurofibromin in the cell. Neurofibromin is a negative regulator of various intracellular signaling pathways involved in the cellular proliferation. Although the loss of heterozygosity in the NF1 gene may predispose NF1 patients to certain malignancies, additional genetic alterations are a prerequisite for their development. The precise nature of these additional genetic alterations is not well defined, and genetic testing of all malignancies in NF1 patients becomes an essential component of future research in this subset of patients. In addition to germline NF1 mutations, alteration of the somatic NF1 gene is associated with sporadic malignancies such as adenocarcinoma of the colon, myelodysplastic syndrome, and anaplastic astrocytoma.

MATERIALS AND METHODS

A comprehensive English and non-English language search for all articles pertinent to malignancies associated with NF1 was conducted using PubMed, a search engine provided by the U.S. National Library of Medicine and the National Institutes of Health. Key words searched included the following: "malignancies associated with NF1", "tumors associated with NF1", and "NF1 and malignancies". A comprehensive analysis in terms age and mode of presentation, investigation and therapeutic modalities, and outcome of the published data was performed and compared with similar information on the sporadic cases.

RESULTS

Malignancies in NF1 patients typically occur at an earlier age and, with an exception of optic pathway gliomas, certain types of malignancies carry a poor prognosis compared with their sporadic counterparts. Malignancies are the leading cause of death in NF1 patients, resulting in a 10- to 15-year decreased life expectancy compared with the general population.

CONCLUSIONS

The lack of well-defined screening tests for early detection and the nonspecific clinical presentation contributes to a poorer outcome in malignancies associated with NF1. Small study group size, mixed patient population, and a lack of uniformity in reporting research results make comparison of treatment outcome for this group difficult. An International Consensus Meeting to address and recommend best practices for screening, diagnosis, management, and follow-up of malignancies associated with NF1 is needed.

A case of neurofibromatosis type 1 coinciding with bilateral pheochromocytomas, multiple gastrointestinal stromal tumors, and malignant peripheral nerve sheath tumor

Neurofibromatosis type 1 (NF1) is associated with benign and malignant neoplasms, but the coincidence of abdominal neoplasms is rare. A 65-year-old woman with NF1 had episodes of nausea, tachycardia, hypertension, and loss of consciousness. Bilateral adrenal tumors were detected by abdominal computed tomography, and plasma and urinary catecholamine levels were elevated. Open bilateral adrenalectomy and histological findings revealed bilateral pheochromocytomas (PCCs). Furthermore, malignant peripheral nerve sheath tumor (MPNST) and multiple gastrointestinal stromal tumors (GISTs) were incidentally found in the abdominal cavity. Early diagnosis of abdominal neoplasms in NF1 patients is important because of the risk of malignancy, organic complications and hemorrhagic-obstructive complications.

Recurrent abdominal complaints caused by a cecal neurofibroma: A case report

Gastrointestinal involvement of neurofibromatosis type 1 (NF1, Von Recklinghausen’s disease) is generally associated with the upper gastrointestinal tract. Abdominal manifestation of NF1 includes several tumors such as malignant peripheral nerve sheath tumors, gastrointestinal stromal tumors and ampulla of vater tumors. However, colonic involvement in NF1 patients is rare. We report a case of a patient presenting with dysphagia, weight loss, intermittent abdominal pain and constipation caused by a single cecal neurofibroma obstructing the ileocecal valve. Also gastrointestinal involvement of the lower tract should be considered in patients with NF1 presenting with abdominal complaints.

Peripheral nerve sheath tumors of the gastrointestinal tract: a multicenter study of 58 patients including NF1-associated gastric schwannoma and unusual morphologic variants

The frequency and morphological spectrum of gastrointestinal peripheral nerve sheath tumors (PNSTs) from consecutive case material has not been studied in the c-KIT era. We reviewed all mesenchymal gastrointestinal (GI) lesions at our departments according to current diagnostic criteria. PNSTs formed the third commonest group of mesenchymal GI tumors with a lower frequency (< or =5%) compared to gastrointestinal stromal tumors (GISTs; approximately 50%) and smooth muscle neoplasms ( approximately 30%). Granular cell tumors (GCTs; n = 31) and schwannomas (n = 22) were the most common types of PNSTs encountered. Rare tumors included neurofibromatosis 1 (NF1)-associated PNSTs (n = 5) and gastric perineurioma (n = 1). Thirteen schwannomas (including also some recent cases) were initially diagnosed as GIST, leiomyoma, or neurofibroma. Unusual histological variants included sigmoid GCT with prominent lipomatous component (n = 1), reticular-microcystic schwannoma of small (n = 1) and large (n = 1) bowel, NF1-associated gastric schwannoma (the first case to date), and psammomatous melanotic colonic schwannoma unrelated to Carney complex (n = 1). PNSTs coexisted with GIST in four patients (three had definite NF1). In conclusion, PNSTs of the GI tract are rare uniformly benign neoplasms that may show schwannian, perineurial, fibroblastic, or mixed differentiation. Most of them (92%) occurred sporadically unassociated with NF1 or NF2. Gastrointestinal PNSTs are still underrecognized by general pathologists. Awareness of their diverse morphology will help to avoid confusing them with smooth muscle neoplasms and GIST that they may closely mimic.