Can vulvar edema be the presenting sign of Crohn's disease? A case series.

Vulvar involvement as an extraintestinal manifestation of Crohn's disease (CD) is a challenging diagnosis considering that vaginal findings may precede gastrointestinal symptoms. The aim of this study is to describe the clinical presentation, radiological findings, and treatment of vulvar Crohn's disease (VCD). We reviewed the time from initial presentation to diagnosis, presenting symptoms, radiological findings, gastrointestinal Crohn's disease Paris classification, and treatment response of five female pediatric patients. All the patients had radiological findings of vulvar inflammation on magnetic resonance imaging. Vaginal symptoms preceded gastrointestinal disease in two of the patients, which correlated with a delay in diagnosis. All patients had active disease on colonoscopy, with three of them having significant colorectal inflammation. Four of the patients were treated with infliximab, while one patient received ustekinumab with a resolution of their symptoms. In conclusion, VCD can precede gastrointestinal symptoms and is easily miss-diagnosed, leading to a delayed Crohn's disease diagnosis and treatment.

Bacterial osteomyelitis in pediatric patients: a comprehensive review.

Bacterial osteomyelitis, an inflammatory response in the bone caused by microorganisms, typically affects the metaphysis in the skeletally immature. Bacterial osteomyelitis possesses a significant diagnostic challenge in pediatric patients due to its nonspecific clinical presentation. Because the metaphysis is the primary focus of infection in skeletally immature patients, understanding the normal physiologic, maturation process of bones throughout childhood allows to understand the pathophysiology of osteomyelitis. Timely and accurate diagnosis is crucial to initiate appropriate treatment, and prevent long-term sequelae and efforts must be made to isolate the causative organism. The potential causative organism changes according to the age of the patient and underlying medical conditions. Staphylococcus Aureus is the most common isolated bacteria in pediatric pyogenic osteomyelitis whereas Kingella Kingae is the most common causative agent in children aged 6 months to 4 years. Imaging plays a pivotal role in the diagnosis, characterization, evaluation of complications, and follow up of bacterial osteomyelitis. Imaging also plays a pivotal role in the evaluation of potential neoplastic and non-neoplastic mimickers of osteomyelitis. In children, MRI is currently the gold standard imaging modality when suspecting bacterial osteomyelitis, whereas surgical intervention may be required in order to isolate the microorganism, treat complications, and exclude mimickers.

Radiologic and Clinical Features of Infantile Hemangioma: Potential Pitfalls and Differential Diagnosis.

Infantile hemangioma (IH) is the most common neoplasm in children, but it may mimic other types of vascular anomalies or nonvascular benign and malignant tumors. In most cases, the clinical appearance, time of onset, and pattern of involution facilitate its diagnosis. Imaging evaluation is not always needed since the IH features at clinical presentation are usually characteristic, but when needed, US and frequently MRI are the imaging modalities of choice. Clinical photography or photographic documentation plays a central role in monitoring these lesions over their clinical course. Photographic documentation can also add confidence and alert the radiologist when interpreting imaging studies. Some vascular anomalies, especially vascular malformations, are a frequent source of confusion, as these may resemble IHs clinically and at imaging. The lack of uniform terminology also hinders an accurate diagnosis. To unify the terminology and minimize confusion, the International Society for the Study of Vascular Anomalies created a helpful classification in 1994. In addition, radiologists need to be aware of and become familiar with other neoplasms in children that may resemble IH to avoid misdiagnosis and unnecessary procedures. Fibrous and lipomatous tumors are examples of benign tumors that can mimic IHs clinically and at imaging, whereas rhabdomyosarcoma, infantile fibrosarcoma, neuroblastoma, and lymphoproliferative disorders are examples of malignant neoplasms. The authors review the features of IH at clinical presentation and imaging evaluation, highlighting its different phases of evolution and stressing the importance of photographic documentation. The authors also review pitfalls of IH with helpful pearls for differentiation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material. See the invited commentary by Khanna and Briones in this issue.

Ankle and Foot Deformities in Children.

Ankle and foot deformity is one of the most common musculoskeletal disorders in children and a leading cause of functional impairment and diminished quality of life when not treated. A spectrum of conditions may produce foot and ankle deformities, with congenital disorders the most frequent cause, followed by acquired conditions. Congenital disorders include congenital talipes equinovarus or congenital clubfoot, metatarsus adductus, skewfoot, congenital vertical talus, and tarsal coalition.Some of these deformities are frequent and easily diagnosed based on clinical features, but clinical overlap between pathologies can be challenging. Thus imaging plays a paramount role in evaluating these patients. Radiographs are the first imaging modality of choice, but they may not be sufficient in infants due to the lack of ossification of the tarsal bones. Ultrasonography allows not only a detailed visualization of the cartilaginous structures but also permits a dynamic study of the foot and ankle. Computed tomography may be necessary in certain conditions such as tarsal coalitions.

Subcutaneous fat necrosis of the newborn: a pictorial essay of an under-recognized entity.

Subcutaneous fat necrosis of the newborn is a self-limited disorder predominantly affecting full-term and post-term neonates during the first 6 weeks after birth. Subcutaneous fat necrosis can be focal or multifocal and affect one or both sides with a predilection for areas of pressure in certain anatomical areas. Subcutaneous fat necrosis of the newborn is associated with perinatal asphyxia and other neonatal and maternal risk factors. Subcutaneous fat necrosis of the newborn presents as a self-limited area of dermal edema followed by indurated subcutaneous plaques, or nontender and mobile nodules, sometimes with skin discoloration [1-3]. The diagnosis is based on the child's history and physical examination, but when in doubt, imaging is helpful. US is the imaging modality of choice to confirm the diagnosis of subcutaneous fat necrosis of the newborn because it provides the best resolution of superficial lesions, requires no sedation and lacks ionizing radiation. US can also help evaluate and characterize other pathologies affecting the superficial subcutaneous soft tissues at this age. Familiarity with subcutaneous fat necrosis of the newborn is important to make a prompt and precise diagnosis and avoid unnecessary imaging tests or invasive procedures.

Update on aneurysmal bone cyst: pathophysiology, histology, imaging and treatment.

Aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare. ABC can involve any bone in the body, and although it has a metaphyseal preference, it can involve any part of a bone and soft tissues. As with any bone tumor, the initial evaluation of ABCs should be done with radiographs followed by magnetic resonance imaging or less frequently computed tomography for further characterization. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. The main differential diagnosis of an ABC in the pediatric population is unicameral bone cyst (UBC) and telangiectatic osteosarcoma, therefore a biopsy is recommended before treatment. The therapeutic options of ABC range from curettage with or without adjuncts such as phenol, liquid nitrogen, argon laser and bone grafting or bone substitutes to more recently employed alternatives such as image-guided sclerotherapy with various sclerosing agents and monoclonal antibodies (e.g., Denosumab).

Pediatric Musculoskeletal Trauma: Upper Limb.

Pediatric upper extremity injuries, acute and chronic due to overuse, are commonly encountered in the clinical setting. However, interpretation of imaging studies is often challenging in pediatric patients because of changing postnatal skeletal development and the broad spectrum of pathology that can potentially occur. This article discusses normal skeletal development and the pathomechanics of skeletal injuries in pediatric patients. It also outlines a framework for imaging as it pertains to the pediatric upper extremity, with specific emphasis on acute and chronic injuries to the shoulder, elbow, forearm, and wrist.

Updates and Advances: Pediatric Musculoskeletal Infection Imaging Made Easier for Radiologists and Clinicians.

Infants and children often present with a wide range of musculoskeletal (MSK) infections in daily clinical practice. This can vary from relatively benign superficial infections such as cellulitis to destructive osseous and articular infections and life-threatening deep soft tissue processes such as necrotizing fasciitis. Imaging evaluation plays an essential role for initial detection and follow-up evaluation of pediatric MSK infections. Therefore, a clear and up-to-date knowledge of imaging manifestations in MSK infections in infants and children is imperative for timely and accurate diagnosis that, in turn, can result in optimal patient management. This article reviews an up-to-date practical imaging techniques, the differences between pediatric and adult MSK infections, the spectrum of pediatric MSK infections, and mimics of pediatric MSK infections encountered in daily clinical practice by radiologists and clinicians.

Breast development in pediatric patients from birth to puberty: physiology, pathology and imaging correlation.

Breast tissue undergoes a series of changes from birth to puberty. The majority of the changes are transient, related to physiological hormonal changes. Although the breast is identical in both sexes at birth, its histology and development will eventually differ. It is important for radiologists to have a basic understanding of endocrinological changes and appearance on imaging to avoid potential pitfalls, particularly on ultrasound, which is the primary modality used to evaluate the breast.

Myeloperoxidase instigates proinflammatory responses in a cecal ligation and puncture rat model of sepsis.

Myeloperoxidase (MPO)-derived hypochlorous (HOCl) reacts with membrane plasmalogens to yield α-chlorofatty aldehydes such as 2-chlorofatty aldehyde (2-ClFALD) and its metabolite 2-chlorofatty acid (2-ClFA). Recent studies showed that 2-ClFALD and 2-ClFA serve as mediators of the inflammatory responses to sepsis by as yet unknown mechanisms. Since no scavenger for chlorinated lipids is available and on the basis of the well-established role of the MPO/HOCl/chlorinated lipid axis in inflammatory responses, we hypothesized that treatment with MPO inhibitors (N-acetyl lysyltyrosylcysteine amide or 4-aminobenzoic acid hydrazide) would inhibit inflammation and proinflammatory mediator expression induced by cecal ligation and puncture (CLP). We used intravital microscopy to quantify in vivo inflammatory responses in Sham and CLP rats with or without MPO inhibition. Small intestines, mesenteries, and lungs were collected to assess changes in MPO-positive staining and lung injury, respectively, as well as free 2-ClFA and proinflammatory mediators levels. CLP caused neutrophil infiltration, 2-ClFA generation, acute lung injury, leukocyte-/platelet-endothelium interactions, mast cell activation (MCA), plasminogen activator inhibitor-1 (PAI-1) production, and the expression of several cytokines, chemokines, and vascular endothelial growth factor, changes that were reduced by MPO inhibition. Pretreatment with a PAI-1 inhibitor or MC stabilizer prevented CLP-induced leukocyte-endothelium interactions and MCA, and abrogated exogenous 2-ClFALD-induced inflammatory responses. Thus, we provide evidence that MPO instigates these inflammatory changes in CLP and that chlorinated lipids may serve as a mechanistic link between the enzymatic activity of MPO and PAI-1- and mast cell-dependent adhesive interactions, providing a rationale for new therapeutic interventions in sepsis.NEW & NOTEWORTHY Using two distinct myeloperoxidase (MPO) inhibitors, we show for the first time that MPO plays an important role in producing increases in free 2-chlorofatty aldehyde (2-ClFALD)-a powerful proinflammatory chlorinated lipid in plasma and intestine-a number of cytokines and other inflammatory mediators, leukocyte and platelet rolling and adhesion in postcapillary venules, and lung injury in a cecal ligation and puncture model of sepsis. In addition, the use of a plasminogen activator inhibitor-1 (PAI-1) inhibitor or a mast cell stabilizer prevented inflammatory responses in CLP-induced sepsis. PAI-1 inhibition also prevented the proinflammatory responses to exogenous 2-ClFALD superfusion. Thus, our study provides some of the first evidence that MPO-derived free 2-ClFA plays an important role in CLP-induced sepsis by a PAI-1- and mast cell-dependent mechanism.

Binge Alcohol Is More Injurious to Liver in Female than in Male Rats: Histopathological, Pharmacologic, and Epigenetic Profiles.

Binge alcohol consumption is a health problem, but differences between the sexes remain poorly defined. We have examined the in vivo effects of three acute, repeat binge alcohol administration on the liver in male and female rats. Sprague-Dawley rats were gavaged with alcohol (5 g/kg body weight) three times at 12-hour intervals. Blood and liver tissues were collected 4 hours after the last binge ethanol. Subsequently, several variables were analyzed. Compared with male rats, females had higher levels of blood alcohol, alanine aminotransferase, and triglycerides. Liver histology showed increased lipid vesicles that were larger in females. Protein levels of liver cytochrome P4502E1 were higher in the liver of females than in the liver of males after binge. Hepatic phospho-extracellular signal-regulated kinase 1/2 and phosph-p38 mitogen-activated protein kinase levels were lower in females compared with males after binge alcohol, but no differences were found in the phospho-C-jun N-terminal kinase levels. Peroxisome proliferator-activated receptor γ-coactivator 1α and cyclic AMP response element binding (CREB) protein levels increased more in female than in male livers; however, increases in phospho-CREB levels were lower in females. Remarkably, c-fos was reduced substantially in the livers of females, but no differences in c-myc protein were found. Binge ethanol caused elevation in acetylated (H3AcK9) and phosphoacetylated (H3AcK9PS10) histone H3 in both sexes but without any difference. Binge alcohol caused differential alterations in the levels of various species of phosphatidylethanol and a larger increase in the diacylglycerol kinase-α protein levels in the liver of female rats compared with male rats. These data demonstrate, for the first time, similarities and differences in the sex-specific responses to repeat binge alcohol leading to an increased susceptibility of female rats to have liver injury in vivo. SIGNIFICANCE STATEMENT: This study examines the molecular responses of male and female rat livers to acute binge alcohol in vivo and demonstrates significant differences in the susceptibility between sexes.

Up-To-Date Practical Imaging Evaluation of Neonatal Soft-Tissue Tumors: What Radiologists Need to Know.

OBJECTIVE: The purposes of this article are to provide an up-to-date overview of neonatal soft-tissue tumors, including information regarding their unique nature, and to present practical imaging techniques and characteristic imaging findings. CONCLUSION: Neonatal soft-tissue tumors are a unique set of neoplasms that often have characteristic clinical and imaging findings. Imaging evaluation, mainly with ultrasound and MRI, plays an important role in the initial diagnosis, staging, preoperative assessment, and follow-up evaluation. Clear understanding of practical imaging techniques combined with up-to-date knowledge of characteristic imaging findings can help the radiologist provide a timely and accurate diagnosis of these neoplasms and can lead to optimal neonatal patient care.

Intraabdominal Lymphatic Malformations: Pearls and Pitfalls of Diagnosis and Differential Diagnoses in Pediatric Patients.

OBJECTIVE: The purpose of this article is to review the practical imaging workup and characteristic imaging appearances of intraabdominal lymphatic malformations (LMs) in the pediatric population with a brief discussion of some common differential diagnoses found in a vascular anomaly clinic. CONCLUSION: LMs are uncommon pediatric lesions. Because of their rarity among LMs overall, a tendency to present later in life than superficial LMs, and often incidental identification, intraabdominal LMs pose a particular diagnostic challenge, and pathologic entities that are more prevalent must be carefully excluded first. Although the diagnosis of most intraabdominal LMs can be reliably based on clear understanding of characteristic imaging findings, histologic correlation may be necessary in some cases.

Pediatric Musculoskeletal Ultrasound: Practical Imaging Approach.

OBJECTIVE: The purpose of this article is to review some of the common indications for pediatric musculoskeletal ultrasound examination, with emphasis given to imaging technique, normal anatomy, and the spectrum of pathologic findings seen in the pediatric population. CONCLUSION: Ultrasound is an essential first-line tool in pediatric musculoskeletal imaging. It aids in determining which patients may benefit from further imaging, including radiography, CT, and MRI.

Acute Pancreatitis in Pediatric Patients: Demographics, Etiology, and Diagnostic Imaging.

OBJECTIVE: The objective of this article is to provide updates on acute pancreatitis in children regarding the imaging findings, causes, and complications based on a review of the current studies in the pediatrics literature. We discuss the epidemiology of acute pancreatitis, the role of imaging and imaging findings in the diagnosis of acute pancreatitis, and the causes and complications of acute pancreatitis. CONCLUSION: The incidence of acute pancreatitis is increasing in children. Imaging plays an important role in the diagnosis of acute pancreatitis because imaging findings can be used to establish the cause of acute pancreatitis, evaluate for complications of acute pancreatitis, and possibly predict the course of the disease.

Low-Flow Vascular Malformation Pitfalls: From Clinical Examination to Practical Imaging Evaluation--Part 1, Lymphatic Malformation Mimickers.

OBJECTIVE: Palpable subcutaneous masses present in various shapes and sizes in the pediatric population and, accordingly, represent a variety of underlying causes. Lymphatic and venous malformations are among the most common pediatric subcutaneous lesions. However, there are congenital and acquired, as well as benign and malignant, soft-tissue masses that can mimic them clinically and at imaging. CONCLUSION: Here, we review the natural history, wide range of clinical presentations, and varied but characteristic imaging appearance of lymphatic malformations that can pose diagnostic difficulties in children. In addition, the clinical and imaging characteristics of some pediatric soft-tissue pathologies that can mimic lymphatic malformations and clues to reach a proper diagnosis are highlighted.

Low-Flow Vascular Malformation Pitfalls: From Clinical Examination to Practical Imaging Evaluation--Part 2, Venous Malformation Mimickers.

OBJECTIVE: The purpose of this article is to review the unusual clinical and radiographic features of venous malformations that can give rise to diagnostic confusion. Entities that can have overlapping clinical and imaging features with venous malformations are also reviewed. CONCLUSION: Venous malformations are congenital endothelial malformations secondary to errors in vascular morphogenesis and are usually diagnosed in the first 2 decades of life. The clinical and imaging features of venous malformations often overlap those of other pathologic entities, creating diagnostic confusion. Furthermore, the clinical presentation and imaging appearance of venous malformations can vary, making the diagnosis challenging. Thorough knowledge of the various clinical and imaging features not only of venous malformations but also of the major potential mimic lesions is crucial for clinicians caring for patients with these lesions.

Different mechanisms for histone acetylation by ethanol and its metabolite acetate in rat primary hepatocytes.

Ethanol and its major metabolite acetate both induced histone H3 acetylation in primary culture of rat hepatocytes. The acetylation by ethanol was dependent on the reactive oxygen species and mitogen-activated protein kinase pathway, whereas that by acetate was independent of both pathways. Ethanol increased CYP2E1 protein expression but acetate had negligible effect. The level of phospho-H2AX, an indicator of DNA breaks, was elevated by ethanol but not by acetate. Ethanol and acetate differentially activated mRNA expression for different genes, e.g., IL-6, PPARγ, c-Fos, Egr-1, and PNPLA3 in hepatocytes. The most striking increase (3-fold) was in PNPLA3 mRNA by ethanol with little change by acetate. It was further shown that acetate inhibited histone deacetylase activity. Taken together, these data establish for the first time that ethanol and acetate exhibit differences in their effects on hepatocytes in gene expression, P-H2AX levels, and the mechanism of histone H3 acetylation. The implications of these differences in the actions of ethanol in liver are discussed.

Uncommon Implantation Sites of Ectopic Pregnancy: Thinking beyond the Complex Adnexal Mass.

Ectopic pregnancy occurs when implantation of the blastocyst takes place in a site other than the endometrium of the uterine cavity. Uncommon implantation sites of ectopic pregnancy include the cervix, interstitial segment of the fallopian tube, scar from a prior cesarean delivery, uterine myometrium, ovary, and peritoneal cavity. Heterotopic and twin ectopic pregnancies are other rare manifestations. Ultrasonography (US) plays a central role in diagnosis of uncommon ectopic pregnancies. US features of an interstitial ectopic pregnancy include an echogenic interstitial line and abnormal bulging of the myometrial contour. A gestational sac that is located below the internal os of the cervix and that contains an embryo with a fetal heartbeat is indicative of a cervical ectopic pregnancy. In a cesarean scar ectopic pregnancy, the gestational sac is implanted in the anterior lower uterine segment at the site of the cesarean scar, with thinning of the myometrium seen anterior to the gestational sac. An intramural gestational sac implants in the uterine myometrium, separate from the uterine cavity and fallopian tubes. In an ovarian ectopic pregnancy, a gestational sac with a thick hyperechoic circumferential rim is located in or on the ovarian parenchyma. An intraperitoneal gestational sac is present in an abdominal ectopic pregnancy. Intra- and extrauterine gestational sacs are seen in a heterotopic pregnancy. Two adnexal heartbeats suggest a live twin ectopic pregnancy. Recognition of the specific US features will help radiologists diagnose these uncommon types of ectopic pregnancy.

MRI-based score helps in assessing the severity and in follow-up of pediatric patients with perianal Crohn disease.

OBJECTIVES: The radiologic healing of perianal fistulizing Crohn disease (PfCD) lags behind the clinical healing. Contrast-enhanced pelvic magnetic resonance imaging (MRI) is the radiologic study of choice used to diagnose PfCD in children. The aim was to study whether the various MRI-based radiologic parameters and score can help in staging and follow-up of patients with PfCD. METHODS: We performed a retrospective chart review of children with PfCD who underwent contrast-enhanced MRI of the pelvis. The demographic profile, clinical status, and laboratory data of the patients at the time of each MRI examination were noted. Based on the clinical status of the patient at the time of MRI examinations, the MRIs were classified into 3 groups: severe disease, mild-to-moderate disease, and asymptomatic. Each MRI examination was reviewed by a radiologist, who was blinded to the clinical status of the patient. RESULTS: Of the radiologic parameters, the number of fistulas, the complexity of fistulas, and the number of abscesses were significantly lower in the asymptomatic group compared with the mild-to-moderate and severe disease groups. The Van Assche MRI-based score was significantly lower in the asymptomatic group compared with the mild-to-moderate disease (P = 0.01) and the severe disease group (P = 0.002). The percentage increase in fistula activity after gadolinium administration was significantly lower in the asymptomatic group compared with the mild-to-moderate disease (P = 0.026) and severe disease (P = 0.019) groups. The MRI-based scores were significantly higher in the MRI examinations performed at diagnosis compared with those that were performed while the patients were receiving the treatment (P = 0.017). CONCLUSIONS: The Van Assche MRI score and the percentage increase in fistula activity after gadolinium administration help in assessing the severity perianal Crohn disease. The Van Assche MRI score may be helpful in documenting healing during therapy of perianal Crohn disease.