Imaging Features of Neurofibromatosis Type 1 in the Abdomen and Pelvis

Myxoid neurofibroma masquerading as lymphatic-venous malformation and poses a diagnostic challenge on fine needle aspiration biopsy

BACKGROUND

Myxoid neurofibromas (NF) are uncommon, benign spindle cell tumors that originate from peripheral nerve sheaths, often posing a diagnostic challenge due to their hypocellularity on cytology specimens. Distinguishing myxoid spindle cell lesions can be challenging, given the broad range of potential differential diagnoses.

CASE PRESENTATION

A 26-year-old female with a past medical history of embolized inguinal, flank, and retroperitoneal venolymphatic malformation presented with a left pelvic pain causing significant disability. CT scan showed an extensive 8.7 cm × 6.6 cm retroperitoneal mass. FNA was performed and alcohol-fixed papanicolaou-stained smears showed a hypocellular specimen with loosely arranged clusters of bland spindle cell proliferation in the background of a mucoid matrix. Spindle cells showed scant cytoplasm and elongated oval-shaped regular nuclei. Prominent nucleoli were not seen. An excisional biopsy revealed a bland spindle cell proliferation in a myxoid background associated with shredded collagen bundles. Immunohistochemical staining showed diffuse positivity for S100 and CD34. Based on the overall findings, a definitive diagnosis of myxoid neurofibroma was rendered.

DISCUSSION

Cytological features of myxoid neurofibroma include the presence of hypocellular spindle-shaped cells arranged in small, loosely organized groups within a myxoid matrix background. Cells exhibit scant cytoplasm with regular oval and elongated nuclei. Nucleoli are typically not identified. The differential diagnosis includes myxoid neurofibroma, myxoma, myxoid liposarcoma, myxoid chondrosarcoma, myxoid dermatofibrosarcoma protuberans, low-grade fibromyxoid sarcoma, and low-grade myxo-fibrosarcoma.

CONCLUSION

We aim to highlight the importance of considering myxoid neurofibroma in the differential diagnosis of hypocellular myxoid spindle cell lesions encountered on fine-needle aspiration cytology.

Adrenal Lesions: A Review of Imaging

Adrenal lesions are frequently incidentally diagnosed during investigations for other clinical conditions. Despite being usually benign, nonfunctioning, and silent, they can occasionally cause discomfort or be responsible for various clinical conditions due to hormonal dysregulation; therefore, their characterization is of paramount importance for establishing the best therapeutic strategy. Imaging techniques such as ultrasound, computed tomography, magnetic resonance, and PET-TC, providing anatomical and functional information, play a central role in the diagnostic workup, allowing clinicians and surgeons to choose the optimal lesion management. This review aims at providing an overview of the most encountered adrenal lesions, both benign and malignant, including describing their imaging characteristics.

A case report of mesenteric involvement in neurofibromatosis type 1

Mutations in the Neurofibromatosis Type 1 (NF-1) gene, which is located on chromosome 17q11.2, are the cause of NF-1, an autosomal dominant hereditary condition in which tumors of the nerve system develop. Neurological, skeletal, and cutaneous abnormalities are symptoms of the condition. Of all gastrointestinal tract lesions, mesentery lesions are the least common. There are many gastrointestinal problems that can accompany mesenteric neurofibromas, or they may not. We describe a case of a 5-year-old kid with mesenteric neurofibromatosis, which results in bowel obstruction and abdominal discomfort. On a CT scan, the mesenteric vasculature was completely encircled by homogenous soft tissue lesions without any vessel wall invasion. Diffuse mesentery lesions were discovered during surgery, although they could not be fully removed.

Neurofibromatosis from Head to Toe: What the Radiologist Needs to Know

Neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2) are autosomal dominant inherited neurocutaneous disorders or phakomatoses secondary to mutations in the NF1 and NF2 tumor suppressor genes, respectively. Although they share a common name, NF1 and NF2 are distinct disorders with a wide range of multisystem manifestations that include benign and malignant tumors. Imaging plays an essential role in diagnosis, surveillance, and management of individuals with NF1 and NF2. Therefore, it is crucial for radiologists to be familiar with the imaging features of NF1 and NF2 to allow prompt diagnosis and appropriate management. Key manifestations of NF1 include café-au-lait macules, axillary or inguinal freckling, neurofibromas or plexiform neurofibromas, optic pathway gliomas, Lisch nodules, and osseous lesions such as sphenoid dysplasia, all of which are considered diagnostic features of NF1. Other manifestations include focal areas of signal intensity in the brain, low-grade gliomas, interstitial lung disease, various abdominopelvic neoplasms, scoliosis, and vascular dysplasia. The various NF1-associated abdominopelvic neoplasms can be categorized by their cellular origin: neurogenic neoplasms, interstitial cells of Cajal neoplasms, neuroendocrine neoplasms, and embryonal neoplasms. Malignant peripheral nerve sheath tumors and intracranial tumors are the leading contributors to mortality in NF1. Classic manifestations of NF2 include schwannomas, meningiomas, and ependymomas. However, NF2 may have shared cutaneous manifestations with NF1. Lifelong multidisciplinary management is critical for patients with either disease. The authors highlight the genetics and molecular pathogenesis, clinical and pathologic features, imaging manifestations, and multidisciplinary management and surveillance of NF1 and NF2. Online supplemental material is available for this article. ^©RSNA, 2022.

Radiologic screening and surveillance in hereditary cancers

Hereditary cancer syndromes comprise an important subset of cancers caused by pathogenic germline mutations that can affect various organ systems. Radiologic screening and surveillance for solid tumors has emerged as a critical component of patient management in permitting early cancer detection. Although imaging surveillance may be tailored for organ-specific cancer risks, surveillance protocols frequently utilize whole-body MRI or PET/CT because of their ability to identify neoplasms in different anatomic regions in a single exam. In this review, we discuss the basic tenets of imaging screening and surveillance strategies in these syndromes, highlighting the more common neoplasms and their associated multimodality imaging findings.

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Pathogenic germline mutations in hereditary cancers cause early-onset distinctive tumors in an organ-specific pattern.

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Geneticist, oncologist, and radiologist coordination facilitates syndrome-appropriate screening and surveillance strategies.

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WB-MRI is a promising comprehensive non-ionizing screening/surveillance modality but with sparse prospective survival data.

Imaging of the Vagina: Spectrum of Disease with Emphasis on MRI Appearance

The vagina is a median fibromuscular structure of the female reproductive system that extends from the vulva inferiorly to the uterine cervix superiorly. As most vaginal lesions are detected at gynecologic examination, imaging performed for nongynecologic indications can frequently cause concomitant vaginal pathologic conditions to be overlooked. The vagina is often underevaluated at routinely performed pelvic transvaginal US because of a narrow scan area and probe positioning. MRI has progressively become the imaging method of choice for vaginal pathologic conditions, as it provides excellent soft-tissue detail with unparalleled delineation of the complex pelvic floor anatomy and helps establish a diagnosis for most vaginal diseases. It is important that radiologists use a focused approach toward understanding and correctly recognizing different vaginal entities that may otherwise go unnoticed. In this case-based review, the authors discuss the key imaging features of wide-ranging vaginal pathologic conditions, with emphasis on appearance at MRI. Knowledge of vaginal anatomy and embryology is helpful in evaluating congenital anomalies at imaging. Often seen incidentally, vaginal inflammation can cause diagnostic confusion. Because of its central location in the pelvis, the vagina can form fistulas to the urinary bladder, colon, rectum, or anus. Vaginal masses can be neoplastic and nonneoplastic and include a myriad of benign and malignant conditions, some of which have characteristic imaging features. Therapeutic and nontherapeutic vaginal foreign bodies include pessaries, vaginal mesh, and packing that can be seen with or without associated complications. Online supplemental material is available for this article. ^©RSNA, 2021.

[Imaging of tumor predisposition syndromes]

CLINICAL ISSUE

Tumor predisposition syndromes (TPS) are a heterogeneous group of genetic cancers. About 10% of the approximately 2200 malignancies in the childhood in Germany develop due to an inherited disposition, whereby TPS may be underdiagnosed. The focus of this review is set on imaging of Li-Fraumeni syndrome, neurofibromatoses, tuberous sclerosis, overgrowth, and neuroendocrine syndromes.

STANDARD RADIOLOGICAL METHODS

In order to detect tumors at an early stage, screening at specific time intervals for each TPS are required. Ultrasonography and magnetic resonance imaging (MRI), especially whole-body MRI, are particularly important imaging modalities.

METHODOLOGICAL INNOVATIONS

Innovative MRI techniques can increase image quality and patient comfort. MRI acquisition time can be significantly reduced through optimized acceleration factors, motion robust radial sequences and joint acquisition and readout of multiple slices during excitation. Thus, shorter MRI examinations can be performed in younger children without anesthesia.

PRACTICAL RECOMMENDATION

Regular screening with ultrasound and MRI can reduce the morbidity and mortality of the patients affected with TPS.

Abdominal imaging findings in patients with SARS-CoV-2 infection: a scoping review

PURPOSE

This scoping review evaluated the currently available data related to abdominal imaging in the SARS-CoV-2 infection.

METHOD

A systematic review of MEDLINE, EMBASE, SCOPUS, and Web of Science was performed from inception to July 15, 2020 using PRISMA-ScR guidelines. The review included case reports and series discussing radiologic manifestations of SARS-CoV-2 infection in abdominal imaging studies. Studies published from inception to March 31, 2020, were independently screened and reviewed by one author, and another author reviewed studies published after March 31 to July 15, 2020. Study screening and full-text review for publications before March 31, 2020, was performed by one author, and another author for publications after March 31 to July 15, 2020.

RESULTS

Thirty-six studies were included in qualitative synthesis. The prevalence of gastrointestinal symptoms is roughly 18% and includes loss of appetite, nausea, vomiting, diarrhea, and abdominal pain. Sixteen percent of COVID-19 cases may only present with gastrointestinal symptoms. Many patients presenting this way demonstrate evidence of COVID-19 incidentally through abdominal CT imaging at the lung bases. Studies published to date have also reported abdominal imaging findings including small and large bowel wall thickening, fluid-filled colon, pneumatosis intestinalis, pneumoperitoneum, intussusception, and ascites.

CONCLUSION

Gastrointestinal manifestations and imaging manifestations of SARS-CoV-2 infection are increasingly reported and warrant specific attention during abdominal imaging.