Leptomeningeal metastases in pineoblastoma.

To cite: Sandip S, Das CJ, Khandelwal RK. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2015210343 DESCRIPTION Pineoblastoma is one of the pineal parenchymal tumours, which are rare tumours and account for approximately 15% of all tumours found in the pineal region. They are malignant tumours that infiltrate the adjacent structures by direct invasion and tend to spread through cerebrospinal fluid (CSF) circulation. MRI helps in depicting the local infiltration and leptomeningeal spread of the disease. Tumour spread occurs as a result of CSF seeding from direct extension of the tumour through the pia or ependymal lining. We present an MRI of a 2-year-old boy, a biopsyproven case of pineoblastoma, which revealed a large lobulated mass in the pineal region. It was iso to hypointense on T1-weighted images (T1WIs) (figure 1A) and heterogeneously hyperintense on T2-weighted images (figure 1B). It showed restricted diffusion, seen as hyperintensity on diffusion-weighted image (figure 1C) and hypointensity on corresponding apparent diffusion coefficient image (figure 1D). It showed heterogeneous enhancement on post-gadolinium T1WIs (figure 1E). It was infiltrating the tectum, cerebral aqueduct and third ventricle, and also extending into the fourth ventricle. Secondary obstructive hydrocephalus was present (figure 2A). Leptomeningeal spread was seen as extensive areas of nodular enhancement on contrast images along the sulcal spaces in the cerebral hemispheres, bilateral sylvian fissures, suprasellar cisterns, cerebellar folia, perimesencephalic cisterns and ventricular wall (figure 2B and C). There were also extensive leptomeningeal metastases along the entire spinal cord, which were seen as nodular enhancement along the spinal cord (figure 2D). The patient received radiotherapy and is doing well at 3 months of follow-up.