Atypical imaging presentation of herpes simplex virus encephalitis in paediatric immunocompromised oncology patients.

INTRODUCTION: We aim to assess the imaging manifestations of brain involvement in paediatric immunocompromised patients with haematological malignancies on chemotherapy presenting with encephalitis and positive HSV CSF PCR. We also aim to determine whether our findings are similar or different to those described in literature for paediatric patients in general. METHODS: A retrospective study was performed in paediatric ALL/lymphoma patients on chemotherapy, and cases with positive CSF HSV-PCR with at least one head MRI scan were included. On imaging, location(typical/atypical), post-contrast enhancement and haemorrhage/diffusivity/gliosis were evaluated. RESULT: A total of 28 scans were included in study from 16 patients fulfilling inclusion criteria, 12 (75%) HSV-1 and 4 (25%) HSV-2. Of the 16 initial scans (CT n = 10, MRI n = 6), 11 were normal (CT = 7, MRI = 4). Fourteen patients had follow-up MRI, of which two had normal scans. On the abnormal initial scan (5/16), only 20% had typical medial temporal/inferomedial frontal/cingulate involvement. Most had frontal (80%), parietal (60%) and non-medial temporal (40%) lesions. Abnormal diffusivity/haemorrhage was absent in all, and postcontrast enhancement was seen in 20%. On follow-up, more patients (33%) had typical medial temporal/inferomedial frontal/cingulate involvement. Widespread atypical site involvement of frontoparietal (75%), thalamus (58%), non-medial temporal (50%), occipital/basal ganglia (33%) and cerebellum (8%) was noted. Most lesions were cortical (91%)/subcortical (75%) with few periventricular lesions (58%). Few showed abnormal diffusivity (16%), post-contrast parenchymal enhancement/haemorrhage (8%), post-contrast meningeal enhancement (25%) and gliosis (16%). CONCLUSION: Immunocompromised paediatric patients with haematological malignancies have widespread atypical brain involvement in herpes simplex encephalitis with lack of diffusion restriction and post-contrast enhancement, likely due to haematogenous spread of HSV across the blood-brain barrier, lack of cellular immunity and limited inflammatory cytokine response.

A study of 853 high grade osteosarcomas from a single institution-Are outcomes in Indian patients different?

AIMS: To review outcomes of 853 patients of primary high grade osteosarcoma operated with curative intent between January 2006 to December 2013. METHODS: All patients underwent appropriate surgical resection after preoperative chemotherapy (non methotrexate based). Excised specimen was analyzed for margins and response to chemotherapy. We analysed various factors (sex, age, size, site, type of surgery, pathologic fractures, margin status, and chemotherapy induced necrosis) for their impact on outcomes. RESULTS: Five year overall survival (OS) for entire cohort was 49% and event free survival (EFS) was 42%. Seventy hundred thirty-eight non metastatic patients had OS of 53% and EFS of 47% at 5 years. The 3 year OS and EFS of the metastatic patients was 22% and 9%, respectively. Analysis of 738 non metastatic patients demonstrated that chemotherapy induced necrosis, size of tumor (< / >8 cms), type of surgery (limb salvage vs amputation) significantly affected overall survival. Local recurrence was 9%. Site of tumor (long bone vs pelvis), type of surgery and chemotherapy induced necrosis influenced local recurrence. CONCLUSIONS: Our patients appeared to have poorer survival compared to most Western data, possibly attributable to large tumors. In contrast to existing data, males (71%) were predominantly affected and only patients with 100% necrosis qualified as good responders regarding OS.