Cytotoxic lesions of the corpus callosum in children: Etiology, clinical and radiological features, and prognosis.

OBJECTIVES: Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated with entities like infection manifested by restricted diffusion on diffusion-weighted cranial magnetic resonance imaging. Our objectives are to evaluate the clinic-radiological spectrum of pediatric patients with cytotoxic lesions of the corpus callosum (CC). METHODS: Children (0-18 years) admitted between February 2017 and May 2020 with splenial lesions showing diffusion restriction on MRI, either isolated or within involvement of other parts of the brain, were included retrospectively. The primary lesions of the CC (e.g. acute disseminated encephalomyelitis, acute ischemic infarction, and glioblastoma multiforme) were excluded. CLOCCs were divided into infection-associated, metabolic disorder-associated, and trauma-associated lesions, as well as CLOCCs involving other entities. Data were collected from the medical databases. RESULTS: Forty-one patients were determined to have CLOCCs. Twenty-five (61%) were infection-associated, nine (22%) were trauma-associated, and three (7%) were metabolic disorder-associated cases, including 2 inherited disorders of metabolism. There were four (10%) patients with other entities, three with epilepsy, and one had an apparent life-threatening event. Six patients had a known etiology among the infection-associated group; one had multisystem inflammatory syndrome caused by COVID-19 and one had been infected by COVID-19 without any complications. All the infection-associated patients with isolated splenial lesions recovered totally, although six patients required intensive care hospitalization. Four trauma-associated patients had sequela lesions. CONCLUSIONS: CLOCCs are associated with a spectrum of diseases, including the new coronavirus, COVID-19 infection. Infection-associated CLOCCs has the best prognosis, although severe cases may occur. Sequelae are possible based on the etiology.

A Case of Familial Hemophagocytic Lymphohistiocytosis Type 4 With Involvement of the Central Nervous System Complicated With Infarct.

BACKGROUND: Familial hemophagocytic lymphohistiocytosis (HLH) is a fatal disease affecting infants and very young children. Central nervous system involvement of HLH can cause catastrophic results. METHOD: We present a case with cranial involvement of familial HLH type 4 who showed diffuse infiltration of white matter complicated with intracranial thrombosis. A 5-year-old girl from a consanguineous couple presented with fever and pancytopenia, and was referred to our hematology unit. Examination revealed fever, lymphadenopathy, and hepatosplenomegaly. Ultrasound examination revealed hepatosplenomegaly and free intra-abdominal fluid. HLH was revealed on bone marrow aspiration biopsy. Defective natural killer and T lymphocyte cytotoxicity using degranulation tests was determined. In the genetic analysis, syntaxin gene mutation was found. On T2-weighted and T2-fluid-attenuated inversion recovery magnetic resonance imaging (MRI), diffuse hyperintense signal changes of cerebral white matter, indicating white matter demyelination, were observed. A second brain MRI showed an acute infarct involving the left temporooccipital region. Immunosuppressive therapy according to the HLH 2004 protocol was started. The infarct resolved but white matter lesions were stable on the brain MRI that was performed 1 month later. Brain MRI taken 4 months after the first examination showed stable cerebral white matter lesions, but hyperintense signal changes appeared in the cerebellar white matter and were regarded as progression. The patient died because of infection despite immunosuppressive therapy. CONCLUSIONS: Physicians managing patients with HLH must be vigilant about the possibility of central nervous system involvement including stroke.

Apparent diffusion coefficient in differentiation of pediatric posterior fossa tumors.

PURPOSE: To investigate the contribution of preoperative apparent diffusion coefficient (ADC) values in the differential diagnosis of pediatric posterior fossa tumors. METHODS: Forty-two pediatric patients (mean age 7.76 ± 4.58 years) with intra-axial tumors in the infra-tentorial region underwent magnetic resonance imaging. ADC measurement was performed using regions of interest, obtained from the solid component of the mass lesions. ADC ratios were calculated by dividing the ADC values from the mass lesions by the ADC values from normal cerebellar parenchyma. Lesions were categorized as juvenile pilocytic astrocytoma (JPA), ependymoma and medulloblastoma based on histopathological diagnosis. ADC values of the lesions and histopathological diagnoses were statistically correlated. RESULTS: Histopathological diagnosis showed that 14 lesions were JPA, 10 were ependymoma; 18 were medulloblastoma. Both ADC values and ADC ratios were significantly correlated with tumor types (p <0.05). Astrocytoma was distinguished from ependymoma with sensitivity 85.7% and specificity 90% using an ADC ratio ≥1.7 and medulloblastoma was distinguished from ependymoma with sensitivity 100% and specificity 88.89% using an ADC ratio ≤1.18. CONCLUSION: Preoperative ADC values could differentiate the main histological subtypes of pediatric posterior fossa tumors with high sensitivity and specificity.

Neuroblastoma in a Child With Wolf-Hirschhorn Syndrome.

Neuroblastoma is the most common extracranial solid tumor of childhood originating from sympathetic nervous system cells. Neuroblastoma has also been diagnosed in conjunction with other congenital conditions such as Hirschsprung's disease, congenital hypoventilation disorder, and neurofibromatosis type 1. Wolf-Hirschhorn syndrome is a congenital disorder caused by microdeletion of short arm of chromosome 4 encoding MSX1 gene with characteristic facial features. We describe a child with dysmorphic features, developmental delay, mental retardation who developed neuroblastoma at 2 years of age and cytogenetic analysis of blood lymphocytes revealed an interstitial deletion of 4p(15,2). To best our knowledge, this report is the first report of neuroblastoma in a child with Wolf-Hirschhorn syndrome; and the reported association may be an important clue for oncological follow-up of patients with Wolf-Hirschhorn syndrome.

Diffusion weighted imaging in differentiating malignant and benign neuroblastic tumors.

PURPOSE: Our aim was to assess diffusion weighted imaging (DWI) of neuroblastic tumors and whether apparent diffusion coefficient (ADC) value may have a role in discrimination among neuroblastoma, ganglioneuroblastoma and ganglioneuroma. MATERIAL AND METHODS: The DWIs (b = 0-800 s/mm(2)) of 24 children (13 girls, 11 boys) who were diagnosed neuroblastic tumors on histopathological examination (neuroblastoma = 15, ganglioneuroblastoma = 5, ganglioneuroma = 4) were evaluated retrospectively. The ADC maps were performed by drawing freehand ROI on PACS (Sectra Workstation IDS7, Linköping, Sweden). RESULTS: We observed a significant decrease in ADC value of neuroblastomas 0.869 ± 0.179 × 10(-3) mm(2)/s compared to ganglioneuroblastomas 0.97 ± 0.203 × 10(-3) mm(2)/s and ganglioneuromas 1.147 ± 0.299 × 10(-3) mm(2)/s (p = 0.026). There was no significant difference in between ganglioneuroblastoma and ganglioneuroma (p = 0.16). In detecting neuroblastomas; the sensitivity, specificity, negative and positive predictive values of ADC were 74, 67, 78.6, 66 % respectively with a cut-off value of 0.93 × 10(-3) mm(2)/s. CONCLUSION: Our study stands out as the most comprehensive study with larger sample size on this topic. Moreover, we are able to suggest a cut-off value which can discriminate neuroblastoma from ganglioneuroblastoma and ganglioneuroma. We believe that ADC will evolve to an objective, quantitative measurement in discrimination among malignant and benign neuroblastic tumors.

Contribution of real-time elastography in diagnosis of polycystic ovary syndrome.

PURPOSE: We aimed to assess the feasibility and reproducibility of real-time elastography (RTE) for displaying the effects of morphological changes in the ovary in polycystic ovary syndrome (PCOS). METHODS: Forty-eight patients diagnosed with PCOS and 48 healthy women were enrolled in the study. Ultrasonography and RTE were performed on the 3rd day of the menstrual cycle. Evaluations were performed independently by two radiologists. Ovarian volume, number of follicles, elasticity pattern, and strain ratio were measured. Elasticity patterns were assessed as hard (type 1; blue or blue-green), moderate (type 2; green or green-yellow) or soft (type 3; red or orange-red). RESULTS: Both radiologists determined the elasticity pattern as mostly type 1 in the PCOS group and type 3 in the control group (P < 0.01). The mean strain ratios obtained by the first and second radiologist were 6.1±1.8 (2.7-10.1) and 6.0±1.5 (3.0-9.0) in PCOS and 3.3±1.2 (1.7-7.2) and 3.2±0.9 (1.7-6.8) in the control group, respectively (P < 0.001). Interobserver agreement was moderate for the elasticity pattern (κ=0.48) and good for the strain ratio (intraclass correlation coefficient, 0.77). A strain ratio of 3.8 was determined as the optimized cutoff point by receiver operating curve analysis. Strain ratio was correlated with the ovarian volume and the number of detected follicles (P < 0.001). CONCLUSION: Elasticity pattern and strain ratio can help identify morphological changes that make PCOS ovaries stiffer than normal ovaries.