Development of a pre-operative scoring system for predicting risk of post-operative paediatric cerebellar mutism syndrome.

BACKGROUND: Despite previous identification of pre-operative clinical and radiological predictors of post-operative paediatric cerebellar mutism syndrome (CMS), a unifying pre-operative risk stratification model for use during surgical consent is currently lacking. The aim of the project is to develop a simple imaging-based pre-operative risk scoring scheme to stratify patients in terms of post-operative CMS risk. METHODS: Pre-operative radiological features were recorded for a retrospectively assembled cohort of 89 posterior fossa tumour patients from two major UK treatment centers (age 2-23yrs; gender 28 M, 61 F; diagnosis: 38 pilocytic astrocytoma, 32 medulloblastoma, 12 ependymoma, 1 high grade glioma, 1 pilomyxoid astrocytoma, 1 atypical teratoid rhabdoid tumour, 1 hemangioma, 1 neurilemmoma, 2 oligodendroglioma). Twenty-six (29%) developed post-operative CMS. Based upon results from univariate analysis and C4.5 decision tree, stepwise logistic regression was used to develop the optimal model and generate risk scores. RESULTS: Univariate analysis identified five significant risk factors and C4.5 decision tree analysis identified six predictors. Variables included in the final model are MRI primary location, bilateral middle cerebellar peduncle involvement (invasion and/or compression), dentate nucleus invasion and age at imaging >12.4 years. This model has an accuracy of 88.8% (79/89). Using risk score cut-off of 203 and 238, respectively, allowed discrimination into low (38/89, predicted CMS probability <3%), intermediate (17/89, predicted CMS probability 3-52%) and high-risk (34/89, predicted CMS probability ≥52%). CONCLUSIONS: A risk stratification model for post-operative paediatric CMS could flag patients at increased or reduced risk pre-operatively which may influence strategies for surgical treatment of cerebellar tumours. Following future testing and prospective validation, this risk scoring scheme will be proposed for use during the surgical consenting process.

Angiomatoid fibrous histiocytoma: A case of local recurrence and metastases to loco-regional lymph nodes that responded to chemotherapy.

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumour with intermediate malignant potential. We report the case of a patient with local recurrence of AFH in two locations and lymph node metastases 18 months after primary surgical excision. The patient was treated with six cycles of ifosfamide and doxorubicin chemotherapy and a further three courses of ifosfamide monotherapy. Reassessment imaging showed a good response to chemotherapy with reduction in size of the two tumours of local recurrence and the lymph node metastases. This case demonstrates that AFH can respond to chemotherapy, even though it is rarely used.

Intussusception: A 14-year experience at a UK tertiary referral centre.

AIMS: Intussusception is the most common cause of acute intestinal obstruction in infants. First line management in uncomplicated cases at our centre is fluoroscopy guided air enema reduction. This study reports a 14 year UK single centre experience highlighting management and outcomes of intussusception in children. METHODS: All cases of intussusception (ICD 10-code K56.1) at a single tertiary referral centre from 2004 to 2017 were analyzed. Data evaluated included patient demographics, clinical presentation, treatment modality(s), complications and outcome(s). RESULTS: Two hundred ninety confirmed cases (69% male) of intussusception were identified during the study period. The median age at presentation was 9.5 months (range 4 days-15 years). One hundred eighty-six (64%) cases occurred in children who were transferred to Alder Hey from peripheral district hospitals. One hundred ninety-six cases (68%) proceeded directly to air enema reduction and successful reduction was achieved in 129 cases (66%). A single case (0.5%) of attempted air enema reduction was complicated by perforation. Early recurrence rate following air enema reduction was 9%. Operative management was indicated in 140 (48%) cases of which 66 required bowel resection (47%). There were no deaths. CONCLUSIONS: We highlight one of the largest single centre UK studies defining practice outcomes for intussusception across the British Isles. Our centre has achieved a 66% success rate of non-operative reduction over 14 years in line with the British Society Pediatric Radiology (BSPR) recommendations and within 5% of the national median metric (71%). Moreover these outcomes were achieved with a very low complication rate (0.5%) from air enema reduction and no mortality in the series. TYPE OF STUDY: Retrospective study. LEVEL OF EVIDENCE: III.

Diagnostic imaging of benign and malignant neck masses in children-a pictorial review.

Neck masses are frequently encountered in pediatric medicine, and can present a diagnostic dilemma for the clinicians involved. There are several means by which neck masses in children can be subdivided, for example by age at presentation, anatomical location including compartments and fascia of the neck, their classical appearance when imaged, or by etiology. When imaging children the clinicians must be mindful of radiation exposure and as such ultrasound (US) is often attempted first. Cross sectional imaging can be helpful for problem solving with CT being particularly useful for assessing the patient in more acute scenarios, for example when there is airway compromise. Nuclear medicine scintigraphy has a role in specific circumstances and can aid in staging in the presence of malignancy. If required, additional acquisition by means of magnetic resonance imaging (MRI) and computed tomography (CT) can be considered. This pictorial review describe the diagnostic imaging of (I) congenital and Developmental Pathologies, including thyroglossal duct cyst, branchial cleft cyst, cystic hygroma, dermoid cyst, thymic cyst and ectopic thymus; (II) neoplastic lesions, including hemangiomas and vascular malformations, pilomatrixoma, neurofibroma, neuroblastoma, rhabdomyosarcoma, papillary thyroid cancer, lymphoma & leukemia; (III) neck masses of Infective causes, including lymphadenitis, retropharyngeal and peritonsilar abscess, salivary gland inflammation; and (IV) other miscellaneous lesions, including ranula, sternocleidomastoid fibromatosis coli, and goiter. Neck masses are common in the pediatric population with a broad and varied differential; malignant etiologies are less frequently encountered when compared with adults but an awareness of its potential is important when reviewing imaging.

Post-operative pediatric cerebellar mutism syndrome and its association with hypertrophic olivary degeneration.

BACKGROUND: The dentato-thalamo-cortical (DTC) pathway is recognized as the anatomical substrate for postoperative pediatric cerebellar mutism (POPCMS), a well-recognized complication affecting up to 31% of children undergoing posterior fossa brain tumour resection. The proximal structures of the DTC pathway also form a segment of the Guillain and Mollaret triangle, a neural network which when disrupted causes hypertrophic olivary degeneration (HOD) of the inferior olivary nucleus (ION). We hypothesize that there is an association between the occurrence of POPCMS and HOD and aim to evaluate this on MR imaging using qualitative and quantitative analysis of the ION in children with and without POPCMS. METHODS: In this retrospective study we qualitatively analysed the follow up MR imaging in 48 children who underwent posterior fossa tumour resection for presence of HOD. Quantitative analysis of the ION was possible in 28 children and was performed using semi-automated segmentation followed by feature extraction and feature selection techniques and relevance of the features to POPCMS were evaluated. The diagnosis of POPCMS was made independently based on clinical and nursing assessment notes. RESULTS: There was significant association between POPCMS and bilateral HOD (P=0.002) but not unilateral HOD. Quantitative analysis showed that hyperintensity in the left ION was the most relevant feature in children with POPCMS. CONCLUSIONS: Bilateral HOD can serve as a reliable radiological indicator in establishing the diagnosis of POPCMS particularly in equivocal cases. The strong association of signal change due to HOD in the left ION suggests that injury to the right proximal efferent cerebellar pathway plays an important role in the causation of POPCMS.