Osteopoikilosis With Germline LEMD3 Mutation Mimicking Bone Metastases in a Girl With a Concurrent Secreting Mixed Germ Cell Tumor.

Osteopoikilosis (OPK) is a rare, benign, asymptomatic bone disease causing dense bone lesions, which could be interpreted as bone metastasis. The symmetric distribution, lack of bone destruction, and location differentiate OPK from metastatic disease. It is essential to be aware of this benign condition to prevent diagnostic errors. We present the case of a 10-year-old female patient with the concurrent diagnosis of secreting mixed germ cell tumor with Yolk Salk Tumor compound and OPK. Physical examination disclosed an abdominal mass, and blood tests showed increased alfa-fetoprotein and human chorionic gonadotropin levels. Computed tomography revealed a pelvic tumor associated with multiple radiodense lesions distributed throughout the bone skeleton. Lesions were inactive on scintigraphy and FDG-PET. Pathology of the bone showed normal bone tissue and ruled out metastasis. The patient achieved complete remission after chemotherapy and surgery and remains in continued complete remission 28 months from diagnosis. The genetic analysis confirmed the LEMD3 germline mutation confirming OPK.

MR Imaging of the Temporomandibular Joint in Juvenile Idiopathic Arthritis: Technique and Findings.

The term juvenile idiopathic arthritis (JIA) encompasses a group of arthritides of unknown cause that begin before 16 years of age and last for at least 6 weeks. Temporomandibular joint (TMJ) involvement has been described in up to 87% of children with JIA and has been associated with all JIA subtypes. TMJ involvement is difficult to detect clinically. In one study, 71% of JIA patients with active TMJ synovitis were asymptomatic and 63% had normal physical examination results. Moreover, the main growth center of the mandible is located in the condyle, separated from the joint space by only a thin layer of fibrocartilage. This makes mandibular growth vulnerable to arthritic changes, eventually resulting in facial asymmetry and retrognathia. Therefore, early detection and treatment of TMJ arthritis are paramount to preserving motility and preventing deformity. As clinical symptoms and physical examination results are not good markers of TMJ involvement, imaging plays a key role in diagnosis and treatment monitoring. Magnetic resonance imaging is the technique of choice for the study of TMJ arthritis. It has the advantages of displaying both soft tissue and bone, is the most sensitive technique for detecting acute synovitis, and is the only one able to demonstrate bone marrow edema. In addition, it allows the assessment of changes to the joint over time and evaluation of the effectiveness of therapeutic interventions. ©RSNA, 2017.

Consensus-driven conceptual development of a standardized whole body-MRI scoring system for assessment of disease activity in juvenile idiopathic arthritis: MRI in JIA OMERACT working group.

OBJECTIVES: Whole body-MRI is helpful in directing diagnostic and treatment approaches, and as a research outcome measure. We describe our initial consensus-driven phase towards developing a whole body-MRI scoring system for juvenile idiopathic arthritis. METHODS: An iterative approach using three rounds of anonymous Delphi surveys followed by a consensus meeting was used to draft the structure of the whole body-MRI scoring system, including the relevant anatomic joints and entheses for assessment, diagnostic item selection, definition and grading, and selection of appropriate MRI planes and sequences. The surveys were completed independently by an international expert group consisting of pediatric radiologists and rheumatologists. RESULTS: Twenty-two experts participated in at least one of three rounds of Delphi surveys and a concluding consensus meeting. A first iteration scoring system was developed which ultimately included the assessment of 100 peripheral, 23 chest, and 76 axial joints, and 64 entheses, with 2-4 diagnostic items graded in each of the items, using binary (presence/absence) and 2-3-level ordinal scores. Recommendations on anatomic MRI planes and sequences were specified as the minimally necessary imaging protocol for the scoring system. CONCLUSION: A novel whole body-MRI scoring system for juvenile idiopathic arthritis was developed by consensus among members of MRI in JIA OMERACT working group. Further iterative refinements, reliability testing, and responsiveness are warranted in upcoming studies.

Broadening the spectrum of neonatal hemochromatosis.

Neonatal hemochromatosis (NH) has been defined as neonatal liver disorder accompanied by extrahepatic siderosis, and gestational alloimmune liver disease (GALD) is the main cause of NH. We report an atypical case of NH that may have gone underdiagnosed. A male infant was born at term after an uneventful antenatal period. At 7 h of life, he was noted to be tachypneic. Chest X-ray was normal and capillary blood gas analysis showed severe lactic acidosis. An extended blood test showed elevated levels of tyrosine and methionine that, after excluding an inborn error of metabolism, led to the diagnosis of acute liver failure. Hyperferritinemia and elevated transferrin saturation were suggestive of NH. Extrahepatic siderosis on MRI confirmed the diagnosis of NH, so even though the infant was in good general condition, a dose of intravenous immunoglobulin was administered and double volume exchange transfusion was performed. Treatment of a suspected case of GALD and prevention in subsequent gestations is imperative.

Preliminary Definitions for Sacroiliac Joint Pathologies in the OMERACT Juvenile Idiopathic Arthritis Magnetic Resonance Imaging Score (OMERACT JAMRIS-SIJ).

OBJECTIVE: To develop definitions for the assessment of magnetic resonance imaging (MRI) pathologies of the sacroiliac joints (SIJ) in juvenile idiopathic arthritis. METHODS: An Outcome Measures in Rheumatology (OMERACT) consensus-driven methodology consisting of iterative surveys and focus group meetings within an international group of rheumatologists and radiologists. RESULTS: Two domains, inflammation and structural, were identified. Definitions for bone marrow edema, joint space inflammation, capsulitis, and enthesitis were derived for joint inflammation; sclerosis, erosion, fatty lesion, and ankylosis were defined for assessing structural joint changes. CONCLUSION: Preliminary consensus-driven definitions for inflammation and structural elements have been derived, underpinning the ongoing development of the OMERACT Juvenile Arthritis MRI SIJ scoring system (OMERACT JAMRIS-SIJ).

Ultrasound to differentiate thyroglossal duct cysts and dermoid cysts in children.

OBJECTIVES/HYPOTHESIS: To determine if ultrasound could differentiate between thyroglossal duct cysts (TGDC) and midline dermoid cysts (DC). STUDY DESIGN: Cohort study. METHODS: A search of pathology reports yielded 91 patients with TGDC or midline DC. Ultrasound images were presented to a radiologist blinded to pathology who evaluated the following: 1) depth of lesion from skin, 2) maximum diameter, 3) dimensions, 4) midline location, 5) distance from base of tongue, 6) tract, 7) wall regularity, 8) wall thickness, 9) margin definition, 10) heterogeneity, 11) internal septae, 12) solid components, 13) intralesional Doppler flow, and 14) posterior enhancement. The predictive power of these variables was evaluated in a multiple logistic regression model. RESULTS: There were 53 TGDC and 38 DC. TGDC were significantly more likely than DC to have the following features: 1) smaller distance from base of tongue, 2) tract, 3) irregular wall, 4) ill-defined margin, 5) internal septae, 6) solid components, and 7) intralesional Doppler flow. Three clinically reliable ultrasound variables were independently able to discriminate between TGDC and DC. A predictive model was fashioned whereby each variable was scored as 0 or 1, with a total score calculated (septae + irregular wall + solid components = TGDC [or SIST] score). We propose a scoring system whereby 0 = suggestive of DC; 1 = suggestive of TGDC; and ≥2 = highly suggestive of TGDC. CONCLUSIONS: It may be possible to differentiate between TGDC and midline DC preoperatively using ultrasound.

MRI thresholds for discrimination between normal and mild temporomandibular joint involvement in juvenile idiopathic arthritis.

BACKGROUND: Currently there is no consensus agreement on the degree of enhancement in normal temporomandibular joints (TMJ) in children, which makes it difficult for clinicians to distinguish between the presence/absence of mild synovitis. Quantitative measurements of synovial and condylar enhancement may be useful additions to current qualitative methods on early MRI diagnosis and follow up of TMJ involvement in JIA. The purpose of the study is to establish thresholds/tendencies for quantitative measures that enable distinction between mild TMJ involvement and normal TMJ appearance based on the degree of synovial and bone marrow enhancement in JIA patients. METHODS: TMJ MRI examinations in 67 children with JIA and in 24 non-rheumatologic children who underwent MRI for neurologic/orbit indications were retrospectively assessed. As a priori determined TMJs of JIA patients were categorized into three groups by experienced staff radiologists based on the degree of synovial and condylar enhancement: no active disease (rheumatologic control), mild and moderate/severe findings. The signal intensity (SI) of the synovial tissue around each condyle and of the bone marrow was measured to calculate the enhancement ratio (ER) and relative SI change. The ER was calculated using signal to noise ratios, while relative SI change was calculated using signal intensities alone. Quantitative measurements of synovial and condylar enhancement of TMJs with mild or moderate/severe findings were compared with the rheumatologic and non-rheumatologic controls. RESULTS: Mean ER values were significantly different between the TMJs without active disease and those with mild and moderate/severe synovial enhancement, with highest values in the moderate/severe group (P < 0.0001). Similar findings were seen for condylar enhancement with P < 0.005. Relative SI change was unable to differentiate TMJs with mild synovitis from the two controls (P > 0.10). 27/60 (45%) TMJs without active disease had osteochondral changes. 8/40 (20%) TMJs in the mild group did not demonstrate any synovial thickening. CONCLUSIONS: Quantitative signal to noise ratios of TMJ synovial and condylar enhancement generate thresholds/tendencies, which offer additional information to differentiate mild synovitis from normal TMJs in JIA patients. Osteochondral changes and synovial thickening may not be reliable indicators of active TMJ involvement and should be differentiated from synovial enhancement.