Mesenteric plexiform neurofibroma associated with Recklinghausen's disease

Magnetic Resonance Imaging, the Virtual Biopsy of Mesenteric Masses

ABSTRACT

The mesentery may be affected by multiple disease processes. Magnetic resonance imaging aids as a virtual pathological biopsy tool in the assessment of mesenteric masses because of superior soft tissue contrast and characterization. In this comprehensive review, we describe in detail the magnetic resonance imaging features of some solid and cystic mesenteric masses, with an emphasis on lesion-specific signal characteristics on T1- and T2-weighted images, diffusion-weighted imaging, and enhancement features on the dynamic postcontrast phase that aid in narrowing the differential diagnosis.

Imaging spectrum of mesenteric masses

Mesenteries are extensions of the visceral and parietal peritoneum consisting of fat, vessels, nerves, and lymphatics. Mesenteric masses have a wide differential diagnosis with neoplastic, infectious, or inflammatory etiologies and can either be solid or cystic. Imaging features are critical for the diagnosis. We review the epidemiology, imaging spectrum, and differentiating features and treatment of mesenteric masses.

Nonoperative Management May Be a Viable Approach to Plexiform Neurofibroma of the Porta Hepatis in Patients with Neurofibromatosis-1

Background

Plexiform neurofibroma (PNF) in the porta hepatis (PH) is an unusual manifestation of neurofibromatosis-1 (NF-1). Resection is often recommended given the risk of malignant transformation. We encountered a challenging case in clinical practice which prompted us to report our findings and perform a systematic review on the management of these tumors.

Methods

We reported the case of a 31-year-old woman with NF-1 and PNF of the PH. PRISMA 2009 guidelines were followed for systematic review.

Results

Our patient was found to have unresectable disease at exploration. After >5 years of follow-up, she continued to have stable disease on imaging. We identified 12 studies/case reports including 10 adult and 6 pediatric patients with PNF of PH. None of the 7 adult patients with NF-1 and PNF of PH underwent a successful tumor resection. All pediatric patients were managed with surveillance alone. All but one pediatric patient had NF-1. None of the reported cases of PNF of PH had malignant transformation.

Conclusion

Our findings suggest that PNFs of PH in the setting of NF-1 are often unresectable and may have an indolent course. Surveillance alone may be a reasonable option in some patients; however, further studies are needed.

Imaging of the pediatric peritoneum, mesentery and omentum

The normal peritoneal structures, including the mesenteries and the omenta, are only a few cell layers thick and are visible on imaging based upon the tissues (e.g., fat) and structures (e.g., blood vessels and lymph nodes) contained within them. These structures become more visible and change in appearance when involved by pathological processes. In this pictorial essay, we discuss the normal anatomy of the various abdominopelvic peritoneal structures and illustrate numerous developmental and acquired diagnoses that involve these structures in the pediatric and young adult population.

Primary malignant tumors of peritoneal and retroperitoneal origin: clinical and imaging features

Peritoneal carcinomatosis and metastatic involvement of the retroperitoneum are manifestations of many organ-based malignancies and lymphoproliferative disorders. Primary malignancies of peritoneal and retroperitoneal origin occur much less frequently, and are difficult to distinguish from metastatic disease on imaging alone. However, the imaging features of these primary tumors, taken in concert with the clinical data, can be helpful in narrowing the scope of the differential diagnosis. This review presents the clinical and imaging features of primary peritoneal and retroperitoneal tumors arising from the various tissue components that comprise the ligaments, mesenteries, and connective tissues of the peritoneal and retroperitoneal spaces.

Gastric outlet obstruction due to neurofibromatosis: an unusual case

Neurofibromatosis type-1 (NF-1), also known as von Recklinghausen disease, is an autosomal dominant condition with an approximate incidence of one in 3000 births. NF-1 is known to involve multiple systems in the body. Abdominal involvement include neurofibroma and tumor growth in the liver, mesentery, and retroperitoneum in addition to gastric and bowel tumors. Gastrointestinal neoplasms occur in up to one quarter of patients. The author reports a rare case of diffuse submucosal neurofibromatosis resulting in gastric outlet obstruction.

A possible cause of multiple intramuscular masses: Mazabraud's syndrome (2007: 11b)

Mazabraud's syndrome is the association of fibrous bone dysplasia and myxomas in soft tissues. We present a new case of this condition in a 52-year-old female patient who presented with pain in the epigastric region. As an incidental finding an abdominal CT showed multiple hypodense intramuscular masses in the upper third of her left thigh associated with a bone lesion in the left femur and left ischiopubic ramus. A plain X-ray showed bone damage in those two bones with a ground-glass pattern and gross trabeculation, consistent with fibrous bone dysplasia. The MRI showed multiple intramuscular masses hypointense in T1-weighted images and hyperintense in T2-weighted images with contrast peripheral enhancement after administering an intravenous contrast agent, with the exception of one of the masses, which showed central enhancement, suggesting multiple myxomas. Very few conditions exist that present as multiple intramuscular masses. The association of multiple intramuscular myxomas and fibrous bone dysplasia should raise suspicion of the presence of this syndrome, and allows for the follow-up of lesions, preventing unnecessary biopsies. The objective of this report is to describe a new case.

Mesenteric plexiform neurofibroma in an 11-year-old boy with von Recklinghausen disease

We experienced the case of an 11-year-old boy diagnosed as having type 1 neurofibromatosis with intraabdominal and pelvic masses. On physical examination, there were multiple café-au-lait spots larger than 15 mm in diameter scattered over the patient's entire body and axillary freckling, but no cutaneous neurofibromas were present. Lisch nodules were detected in the iris by a slit lamp. A large, firm mobile mass was palpated in the lower abdomen. Abdominal computed tomographic scan showed the hypodense masses in the lower abdomen and pelvic cavity. At laparotomy, a 16 x 9-cm, firm nodular mass along the mesentery of the terminal ileum and ascending colon was found. The mesenteric mass was encasing the superior mesenteric vessels and extending into the serosa of the intestine. The mass was incompletely excised together with affected intestine. However, resection of the rectum could not be performed because of the extensive involvement of the entire mesorectum. Histopathologic study revealed a plexiform neurofibroma involving the mesentery and intestine without evidence of malignant transformation. The postoperative course was uneventful. Ten months after the operation, a magnetic resonance imaging showed no interval change of the mesorectal mass.

From the archives of the AFIP: abdominal neoplasms in patients with neurofibromatosis type 1: radiologic-pathologic correlation

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders. NF1 is a complex disease resulting from a spectrum of mutations that may occur at many locations along the large, complex NF1 gene, which is located on chromosome 17. Mutations of the NF1 gene lead to abnormal tumor suppression. Consequently, patients with NF1 have an increased prevalence of benign and malignant neoplasms throughout the body. There are five categories of NF1 tumors that occur in the abdomen: neurogenic, neuroendocrine, nonneurogenic gastrointestinal mesenchymal, embryonal, and miscellaneous. Many of these tumors are age related, occur at specific anatomic locations, and have unique imaging features. Notably, many patients have a variety of organs affected because there is a high prevalence of multiple tumors occurring in the same patient. Neurofibromas are the most common benign neoplasms and may occur in the retroperitoneum or visceral organs. Malignant peripheral nerve sheath tumor is an aggressive malignancy that is the most common malignant tumor of the abdomen in patients with NF1. Interpreting abdominal imaging studies in patients with NF1 can be challenging because of the wide spectrum and diverse nature of tumors that occur in this disease.

Primary neoplasms of peritoneal and sub-peritoneal origin: CT findings

Peritoneal carcinomatosis is a common metastatic manifestation of many organ-based malignancies, particularly carcinomas of the gastrointestinal tract and ovaries. Primary neoplasms of peritoneal and sub-peritoneal origin occur much less frequently than metastatic peritoneal involvement from a known or occult primary tumor; however, these rare primary lesions (peritoneal mesothelioma, papillary serous carcinoma, desmoplastic small round cell tumor, benign and malignant mesenchymal tumors, lymphoproliferative disorders) are often first detected at computed tomography (CT) and should be considered in the absence of a known or suspected organ-based malignancy. A precise diagnosis based on imaging findings alone is often not possible. Furthermore, distinguishing a benign from a malignant process and a primary from a metastatic process is also challenging. Nevertheless, CT features combined with the patient's relevant clinical and demographic data can help narrow the differential diagnosis for a peritoneum-based neoplasm in many cases. CT is useful not only for the detection, characterization, and staging of primary neoplasms of peritoneal and subperitoneal origin, but also for guiding biopsy for tissue diagnosis.

Abdominal migraine in children with neurofibromatosis type 1: a case series and review of gastrointestinal involvement in NF1

BACKGROUND

Symptomatic involvement of the gastrointestinal tract in children with neurofibromatosis type 1 (NF1) is rare. Most reported complications in adults are caused by the presence of neurofibromas in the stomach, small bowel, or mesentery. In contrast, abdominal pain in children with NF1 may be the result of nonanatomic causes, such as migraine. There are no previous reports of an association between abdominal migraine and NF1.

METHODS

Children with abdominal migraine were identified from a group of children with NF1, all of whom had been followed up for a minimum of 3 years. Medical records of cases were reviewed independently by two authors. MEDLINE was searched via PubMed for all reports of children with NF1 and any associated gastrointestinal involvement.

RESULTS

Six children with NF1 and intermittent, episodic, severe abdominal pain are reported. Investigations for obstructive or inflammatory causes of abdominal pain were negative. All patients had previously been diagnosed with migraine headaches by a neurologist. In five of the six patients, propranolol (10-15 mg three times daily) resulted in relief of their abdominal pain within days of starting therapy. Our review identified 24 children in the medical literature with gastrointestinal complications of NF1, mostly secondary to visceral neurofibromas. In almost all of these cases, clinical examination and simple radiologic investigations led to the definitive diagnosis. There were no reports of abdominal migraine complicating NF1.

CONCLUSIONS

Abdominal pain secondary to migraine is an unrecognized cause of abdominal pain in children with NF1 and may be more common than anatomic causes of abdominal pain in children with NF1. In children with NF1 and severe recurrent abdominal pain in whom an evaluation for anatomic lesions is negative, a trial of migraine therapy may be indicated.

Neurofibromatosis Type 1: A Diagnostic Mimicker at CT

Neurofibromatosis type 1 (NF1) is the most common of the phakomatoses and has a variety of localized or, more frequently, systemic manifestations throughout the thorax, abdomen, pelvis, and extremities. Classic computed tomographic (CT) findings in NF1 with thoracic involvement include small, well-defined subcutaneous neurofibromas, focal thoracic scoliosis, posterior vertebral scalloping, enlarged neural foramina, and characteristic rib abnormalities due to bone dysplasia or erosion from adjacent neurofibromas. However, more atypical manifestations are occasionally seen, and magnetic resonance (MR) imaging can be useful in equivocal cases. NF1 with abdominopelvic involvement tends to arise in the retroperitoneal, mesenteric, and paraspinal regions; it may be quite extensive and therefore difficult to distinguish from adenopathy at CT. The multiplanar capabilities of MR imaging, particularly with T2 weighting, make this modality helpful in evaluating affected patients and making the diagnosis. The classic peripheral manifestations of NF1 include limb hemihypertrophy, pseudarthrosis, peripheral nerve neurofibromas, and subcutaneous common and plexiform neurofibromas. In some cases of NF1, imaging findings are inconclusive, and biopsy and subsequent pathologic analysis are required. Familiarity with the various manifestations of NF1 in different anatomic locations is important in making the diagnosis and optimizing postdiagnostic treatment.

Molecular genetic diagnosis of the familial myxoma syndrome (Carney complex)

We describe an individual in whom molecular genetic testing provided a diagnosis of the Carney complex, an autosomal dominant syndrome comprising cutaneous and cardiac myxomas, spotty pigmentation of the skin, and endocrinopathy. Recently, we localized the Carney complex disease gene to chromosome region 17q2. Our patient was a member of a family segregating the Carney complex, but was not, himself, initially thought to be affected. Haplotype analysis based on genotyping studies with 17q2 microsatellites predicted that this individual was, in fact, affected by Carney complex and was at risk for development of myxomas. Further clinical evaluation and re-review of prior pathologic studies, then, confirmed the DNA-based diagnosis. This report highlights the difficulty in establishing a diagnosis of Carney complex based on clinical and pathologic findings alone, and we suggest that molecular genetic analyses provide an important diagnostic method for this familial myxoma syndrome.