A Rare Presentation of Pseudo-Pneumoperitoneum Secondary to Chilaiditi Sign and Chilaiditi Syndrome in Two Pre-adolescent Females: A Case Series.

Chilaiditi sign is defined as the interposition of the colon or small intestine between the liver and the right diaphragm in the absence of symptoms. Chilaiditi syndrome refers to the condition where the Chilaiditi sign is associated with symptoms including abdominal pain. In this series, we present the cases of two pre-pubescent patients with these rare conditions.  A 10-year-old female with a history of autism, IgA deficiency, and constipation presented for gastrointestinal studies due to weight loss and constipation. An abdominal X-ray revealed bowel gas under the right hemidiaphragm and colonic interposition between the diaphragm and the liver, raising concerns for the Chilaiditi sign. She underwent a bowel cleanout, with studies revealing colonic dysmotility and compartmentalization of the sigmoid colon and rectum with the absence of coloanal reflex. A nine-year-old female with a history of constipation, developmental delay, and hypotonia presented with abdominal pain, vomiting, constipation, and decreased appetite. She also manifested tachypnea, abdominal distension, and abdominal tenderness, with an abdominal X-ray revealing a dilated colon interposed between the liver and diaphragm, confirming Chilaiditi syndrome. Prior gastrointestinal studies showed dilated and redundant sigmoid colon and dyssynergia. The treatment entailed rectal irrigations and catheter decompression, which led to the improvement of symptoms. Conservative treatment is the treatment of choice for patients with Chilaiditi sign or Chilaiditi syndrome. It is important to distinguish Chilaiditi syndrome, a common cause of pseudo-pneumoperitoneum, from true pneumoperitoneum, as this diagnosis warrants immediate surgical intervention. Surgical treatment is indicated when there are signs of bowel obstruction or ischemia and for cases with recurrent Chilaiditi syndrome. Raising awareness about this condition is important to reduce the incidence of misdiagnosed surgical emergencies and resulting exploratory surgeries, as well as to avoid high-risk colonoscopies. Chilaiditi sign and Chilaiditi syndrome are relatively uncommon entities, and their prevalence is very rare in the pediatric population. Hence, we believe this case series will contribute to providing clinical awareness of these major complications and avoiding invasive interventions due to the inaccurate diagnosis of these conditions as pneumoperitoneum.

Pediatric focal calvarial lesions: an illustrated review.

Focal skull lesions in children can be diagnostically challenging with a wide variety of potential etiologies. Understanding the diverse pathologies and recognizing their associated clinical and imaging characteristics is crucial for accurate diagnosis and appropriate treatment planning. We review pertinent anatomy of the scalp and calvarium and review different pathologies that can present with focal skull lesions in pediatric patients. These include neoplastic, non-neoplastic tumor-like, congenital, post traumatic, and vascular-associated etiologies. We review the key clinical and imaging features associated with these pathologies and present teaching points to help make the correct diagnosis. It is important for radiologists to be aware of the common and rare etiologies of skull lesions as well as the clinical and imaging characteristics which can be used to develop an accurate differential to ensure a timely diagnosis and initiate appropriate management.

Imaging recommendations in pediatric lymphoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are both malignancies originating in the lymphatic system and both affect children, but many features differ considerably, impacting workup and management. This paper provides consensus-based imaging recommendations for evaluation of patients with HL and NHL at diagnosis and response assessment for both interim and end of therapy (follow-up).

Imaging of pediatric neuroblastoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

Neuroblastoma is the most common extracranial solid neoplasm in children. This manuscript provides consensus-based imaging recommendations for pediatric neuroblastoma patients at diagnosis and during follow-up.

Pulmonary Metastases of Chondroblastoma in a Pediatric Patient: A Case Report and Review of Literature.

Chondroblastoma is a locally destructive, cartilaginous bone tumor that accounts for a small percentage of cases of primary bone tumors. Although considered a benign tumor, chondroblastoma can locally recur and can rarely metastasize. Here, we report a rare presentation of a locally recurrent chondroblastoma with pulmonary metastases. A 13-year-old female presented with palpitations, dry cough, difficulty breathing, and chest tightness four years after her original surgical resection of tibial chondroblastoma. On chest CT, multiple pulmonary soft tissue nodules with confluent punctate areas of calcification were seen. The patient underwent robotic-assisted bilateral pulmonary wedge resections. She is now undergoing denosumab therapy. This case underlined the importance of suspecting metastatic disease in patients with a history of chondroblastoma when pulmonary nodules are detected on imaging.

Rhabdomyosarcoma With Diffuse Bone Marrow Metastases.

Rhabdomyosarcoma is a highly aggressive cancer that is generally considered a disease of childhood. A vast majority of cases occur in those below the age of 20. Rhabdomyosarcoma can occur in any soft tissue in the body but is primarily found in the head, neck, orbit, genitourinary tract, genitals, and extremities. Prognosis is closely tied to the location of the primary tumor and the extent of metastatic spread. As with most sarcomas, rhabdomyosarcoma has a pattern of hematogenous spread which favors metastasis to the lungs. Other common areas include bone marrows, liver, breasts, and brain. One unusual pattern is the presence of diffuse bone marrow metastases in absence of significant soft tissue disease other than primary (no distant nodal disease, absence of visceral disease in chest and abdomen). Frequently in such cases, patients may have initial presentation similar to hematologic malignancy especially when the primary tumor is not evident. This pattern has been rarely described in the radiology literature. This pattern appears to be well documented in pathology literature. Even more rarely, in some cases, the primary tumor site may not be found after imaging and may remain undetermined even postmortem - only diagnosed by bone marrow aspiration. Awareness of this unique pattern is clearly important for radiologists, especially pediatric radiologists, as misdiagnosis can lead to delay in appropriate treatment that ultimately results in increased mortality. We present a case of rhabdomyosarcoma with this unique pattern of bone marrow metastases in which initial differential diagnosis favored a leukemic picture. This paper will go over the diagnostic techniques utilized throughout our patient's disease course as well as treatment.

Pearls and Pitfalls of Imaging in Pediatric Brain Tumors.

The central nervous system (CNS) tumors constitute the most common type of solid tumors in the pediatric population. The cerebral and cerebellar parenchyma are the most common site of pediatric CNS neoplasms. Imaging plays an important role in detection, characterization, staging and prognostication of brain tumors. The focus of the current article is pediatric brain tumor imaging with emphasis on pearls and pitfalls of conventional and advanced imaging in various pediatric brain tumor subtypes. The article also elucidates changes in brain tumor terms and entities as applicable to pediatric patients, updated as per World Health Organization (WHO) 2016 classification of primary CNS tumors. This classification introduced the genetic and/or molecular information of primary CNS neoplasms as part of comprehensive tumor pathology report in the routine clinical workflow. The concepts from 2016 classification have been further refined based on current research, by the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) group and published in the form of updates. The updates serve as guidelines in the time interval between WHO updates and expect to be broadly adopted in the subsequent WHO classification. The current review covers most pediatric brain tumors except pituitary tumors, meningeal origin tumors, nerve sheath tumors and CNS lymphoma/leukemia.

Utility of paramagnetic rim lesions on 1.5-T susceptibility phase imaging for the diagnosis of pediatric multiple sclerosis.

BACKGROUND: Studies have suggested that paramagnetic rim lesions on 7-tesla (T) and 3-T susceptibility-based brain MRI are specific features of multiple sclerosis (MS) lesions in adults. OBJECTIVE: The aim of this study was to investigate whether the presence of paramagnetic rim lesions on 1.5-T phase images can help discriminate pediatric patients with MS from those with other demyelinating diseases. MATERIALS AND METHODS: In this retrospective study we reviewed brain MRIs performed on 1.5-T scanners that included susceptibility-weighted imaging (SWI) sequences with phase images in children younger than 18 years diagnosed with MS and other acquired demyelinating syndromes. In each case, five white matter lesions were selected using T2/fluid-attenuated inversion recovery images for further paramagnetic rim evaluation on SWI. Two researchers performed independent assessments of the presence of paramagnetic rim lesions. Discrepancies between them were settled by consensus, with input from a senior neuroradiologist. RESULTS: We included 13 children diagnosed with MS and 16 children diagnosed with non-MS demyelinating diseases and analyzed a total of 132 focal white matter lesions. Seventy-one percent of the lesions in the MS group had paramagnetic rims, while none of the lesions in the non-MS group had rims. All but one of the children with MS had at least one lesion with a paramagnetic rim. The presence of one lesion with a paramagnetic rim on 1.5-T phase-contrast images resulted in 70% sensitivity and 100% specificity for MS. CONCLUSION: Paramagnetic rim lesions detected on 1.5-T phase-contrast MR images can help discriminate MS from other acquired demyelinating syndromes in the pediatric population.

Anophthalmia, Global Developmental Delay, and Severe Dysphagia in a Young Girl With 14q22q23 Microdeletion Syndrome.

14q22q23 microdeletion syndrome, also called Frias syndrome, is an extremely rare partial deletion of the long arm of chromosome 14 characterized by the anomalies of the pituitary gland, eyes, and hand/foot. Intellectual disability and facial dysmorphism are other common manifestations. Haploinsufficiency of the genes bone morphogenetic protein 4 (BMP4) and orthodenticle homeobox 2 (OTX2) accounts for most of the phenotypic abnormalities seen in these patients. There are only a few cases reported with Frias syndrome in the literature, and there are multiple variations present, which are not well recognized due to different set of genes involved. This case report presents the case of a young child with a deletion in 14q22.2q23.1 region containing both BMP4 and OTX2 genes as well as sineoculis homeobox homolog 1 (SIX1) and sineoculis homeobox homolog 6 (SIX6) genes. The case report illustrates the wide phenotypic findings associated with these genes along with additional unique findings that previously have not been commonly reported.

Neuroimaging of Propofol Infusion Syndrome: A Case Report and Review of Literature.

A school-age boy with a complex medical history underwent a minor elective surgical procedure. Propofol was used for sedation during the procedure. The patient could not be awakened post-operatively. Laboratory findings demonstrated metabolic lactic acidosis, leukocytosis with bandemia, and transaminitis. Neuroimaging demonstrated findings that were consistent with hypoxic-ischemic or toxic-metabolic brain injury involving the bilateral basal ganglia, hippocampi, and cerebellum. The patient's condition progressively worsened over the course of the following few weeks, and brain death was confirmed by scintigraphy seven weeks later. Prompt neuroimaging in unresponsive patients with suspected propofol infusion syndrome (PRIS) is of critical importance in detecting neurologic injuries, excluding alternative diagnoses, and determining prognostication.

Imaging mimics of chronic recurrent multifocal osteomyelitis: avoiding pitfalls in a diagnosis of exclusion.

Chronic recurrent multifocal osteomyelitis (CRMO) is a pediatric autoinflammatory disorder that is characterized by multiple sterile inflammatory bone lesions with a relapsing and remitting course. CRMO belongs to the autoinflammatory family of rheumatologic disorders based on absence of significant titers of autoantibodies and autoreactive T-lymphocytes. In absence of pathognomonic clinical, radiographic or pathological features, diagnosis can be challenging. CRMO shares imaging features with other diseases. It is important for radiologists to be able to differentiate other diseases from CRMO because prognosis varies from completely benign to frankly malignant. In this article we first present the clinical and imaging features of CRMO to help readers gain an understanding of the disease process, then discuss our imaging approach to CRMO and review other disease processes that sometimes share similar imaging findings to CRMO and review differentiating features to help avoid misdiagnoses.

Neurocristopathies: Enigmatic Appearances of Neural Crest Cell-derived Abnormalities.

The neural crest is an important transient structure that develops during embryogenesis in vertebrates. Neural crest cells are multipotent progenitor cells that migrate and develop into a diverse range of cells and tissues throughout the body. Although neural crest cells originate from the ectoderm, they can differentiate into mesodermal-type or endodermal-type cells and tissues. Some of these tissues include the peripheral, autonomic, and enteric nervous systems; chromaffin cells of the adrenal medulla; smooth muscles of the intracranial blood vessels; melanocytes of the skin; cartilage and bones of the face; and parafollicular cells of the thyroid gland. Neurocristopathies are a group of diseases caused by the abnormal generation, migration, or differentiation of neural crest cells. They often involve multiple organ systems in a single person, are often familial, and can be associated with the development of neoplasms. As understanding of the neural crest has advanced, many seemingly disparate diseases, such Treacher Collins syndrome, 22q11.2 deletion syndrome, Hirschsprung disease, neuroblastoma, neurocutaneous melanocytosis, and neurofibromatosis, have come to be recognized as neurocristopathies. Neurocristopathies can be divided into three main categories: dysgenetic malformations, neoplasms, and combined dysgenetic and neoplastic syndromes. In this article, neural crest development, as well as several associated dysgenetic, neoplastic, and combined neurocristopathies, are reviewed. Neurocristopathies often have clinical manifestations in multiple organ systems, and radiologists are positioned to have significant roles in the initial diagnosis of these disorders, evaluation of subclinical associated lesions, creation of treatment plans, and patient follow-up. Online supplemental material is available for this article. ©RSNA, 2019.

Brain metastases from adenocarcinoma of the lung with truly cystic magnetic resonance imaging appearance.

Metastatic disease represents over half of all malignancies in brain parenchyma, and carcinoma when metastatic will often spread to the brain, with lung and breast tumors being the most common culprits. The suggestive features of metastatic disease on magnetic resonance imaging include peritumoral, vasogenic edema and avid postcontrast enhancement. We present the case of a 50-year-old male with an established diagnosis of metastatic adenocarcinoma of the lung treated with erlotinib who developed multiple cystic brain lesions on surveillance MRI. These cysts demonstrated T2 prolongation, suppressed completely on FLAIR, lacked surrounding edema, and featured a complete lack of enhancement. Due to the ambiguous imaging findings, brain biopsy was performed to establish the diagnosis. The pathology revealed a single layer of malignant cells lining brain parenchyma and focal areas of glandular growth. The intracranial lesions responded well to total brain radiation. This case is unique for the imaging findings most characteristic of simple cysts in biopsy-proven metastatic disease and may relate to the effects of erlotinib on metastatic brain tumors.

Malignant transformation and leptomeningeal spread of recurrent ganglioglioma: case report and review of literature.

Gangliogliomas are rare, typically benign low grade tumors which usually occur in the supratentorial compartment, more commonly in the pediatric age group. Malignant transformation of a low grade ganglioglioma in the absence of prior radiation therapy is exceptionally rare with only 17 such cases previously reported. The author present an additional case of malignant transformation of recurrent ganglioglioma. Unlike the prior cases however, the recurrent tumor in our case showed prominent intratumoral hemorrhage and widespread leptomeningeal spread. The rapidly fatal course in our case was likely secondary to tumor dedifferentiation which is supported by serial histopathological specimens.

Multimodality Imaging Spectrum of the Extranodal Lymphomas in the Head and Neck-A Pictorial Review.

Lymphoma is the second most common malignant neoplasm of the head and neck region, involving the nodal and/or extranodal sites or both in a variable fashion. Lymphoma may mimic a variety of tumors in this region depending on the subsite involved. The usual presentation of lymphomatous disease is presence of multiple enlarged, often conglomerate, lymph nodes without significant necrosis. Extranodal lymphomas demonstrate more complex radiologic features, but careful evaluation can identify distinct imaging patterns to suggest extranodal lymphomatous disease from other more common lesions. Knowledge of these imaging features can help raise suspicion for lymphoma as a differential consideration. This can be of critical importance since further work-up and management can be vastly different between lymphomatous disease and other disease entities. The authors present a pictorial review of the spectrum of imaging findings in extranodal head and neck lymphomas.

Retroperitoneal Cystic Malignant Fibrous Histiocytoma Mimicking a Psoas Abscess.

Primary neoplasms in the psoas muscle including schwannoma and soft tissue sarcoma with secondary cystic degeneration are rare entities. They are difficult to distinguish from psoas abscess purely based on radiological findings. Malignant fibrous histiocytoma (MFH) in the retroperitoneum is an uncommon entity in contrast to liposarcoma and leiomyosarcoma. Psoas abscess is a common infection in the retroperitoneum, especially in regions where tuberculosis is endemic. In the current case, the patient presented with gradually progressive lower abdominal pain and raised erythrocyte sedimentation rate (ESR), lymphocyte count and sputum positive for acid fast bacilli. There was a presence of previous history of skeletal tuberculosis. Imaging revealed well-defined multilocular cystic lesion involving the left psoas muscle which along with the clinical scenario suggested psoas abscess. However, post-operative biopsy showed the lesion to be a MFH with extensive cystic degeneration. To the best of our knowledge, cystic MFH mimicking an abscess has been previously reported only once in an oncology literature.

Primary spinal primitive neuroectodermal tumor on MR imaging.

Neoplasms in the region of filum terminale are not uncommon. Myxopapillary ependymoma is the commonest tumor at this location. The differentials reported for this entity are nerve sheath tumor, meningioma, paraganglioma, intradural metastases, lymphoma, other varieties of ependymoma, subependymoma, astrocytoma, ganglioglioma, hemangioblastoma, and primitive neuroectodermal tumor (PNET). PNET may very rarely present as an intradural thoracolumbar mass. We present pre- and post-therapy magnetic resonance imaging (MRI) features of a patient with proven primary spinal primitive neuroectodermal tumor (PSPNET) of peripheral subtype.

Synchronous multifocal osteogenic sarcoma on multimodality imaging including bone scintigraphy.

Multifocal osteosarcoma is diagnosed when there are two or more lesions in the skeleton without presence of pulmonary metastases. It is further classified as synchronous type when the patient is demonstrated to have more than one lesion simultaneously at presentation and is known as Synchronous Multifocal Osteogenicsarcoma (MOGS). We report a case of synchronous MOGS showing its multimodality imaging findings including nuclear scan findings with pathological correlation.

Retroperitoneal extragastrointestinal stromal tumor: radiologic pathologic correlation.

Neoplasms with histology and immunohistochemistry similar to gastrointestinal stromal tumors may occur primarily outside the gastrointestinal tract, usually in the omentum and mesentery. These are referred to as extragastrointestinal stromal tumors (EGISTs). Retroperitoneum is a very rare site for such neoplasms. We report a patient with EGIST in the retroperitoneum, elaborating the cross-sectional imaging and histopathologic findings.

Malignant mesenchymal renal tumor: a rare case of primary renal fibrosarcoma.

Malignant mesenchymal neoplasms of kidney constitute a rare group of tumors. Primary fibrosarcoma of kidney is an extremely rare subtype of primary malignant mesenchymal renal neoplasms. An elderly female presented with a gradually increasing abdominal lump and mild abdominal discomfort. On cross-sectional imaging, the lesion showed features suggestive of an atypical renal mass not conforming to either ball or bean type growth pattern. The mass was surgically removed and on histopathological and immunohistological investigations diagnosed to be primary renal fibrosarcoma.