The macrophages that clear these cells are unable to eliminate the waste product, which accumulates in fibrils, and turn into Gaucher cells, which appear on light microscopy to resemble crumpled-up paper.The exact mechanism of neurotoxicity is not understood, but it is thought to involve a reaction to glucosylsphingosine.Different mutations in the GBA (beta-glucosidase) gene determine the remaining activity of the enzyme. In type I, there is some residual activity of the enzyme, accounting for the lack of neuropathology in this type. Although there is some correlation between genotype and phenotype, neither the amount of stored lipids, nor the residual enzyme activity correlates well with disease symptoms. This circumstance has called for alternative explanations accounting for disease symptoms including

jamming of the endo/lysosomal system
ER stress
altered lipid composition of membranes throughout the cell, including the plasma membrane, and consequent changes in the dynamic and signaling properties of the cell membrane
inflammation caused by cytokine secretion as a result of sphingolipid accumulation, and neurodegeneration caused by the accumulation of glucosylsphingosine, a neurotoxinHeterozygotes for particular acid beta-glucosidase mutations carry about a five-fold risk of developing Parkinsons disease, making this the most common known genetic risk factor for Parkinsons.Cancer risk may be increased, particularly myeloma. This is thought to be due to accumulation of glucosylceramide and complex glycosphingolipids.The role of inflammatory processes in Gaucher disease is poorly elucidated. However, sphingolipids are known to participate in inflammation and apoptosis, and markers of macrophage activation are elevated in people with Gaucher disease.
classified this tumour into two subtypes: 

1) medulloepithelioma not otherwise specified
2) medulloepithelioma with differentiation into astrocytes, oligodendrocytes; ependymal cells; neuronal cells; others (melanin, mesenchymal cells); and mixed cellular elements. Treatment
Total resection of the tumour, followed by radiation therapy is the standard treatment modality. Medulloepithelioma of the ciliary body may necessitate enucleation of the eye. Radiation therapy alone may prolong survival. Aggressive chemotherapy with autologous bone marrow transplant is used for metastatic medulloepitheliomas. Prognosis
Medulloepithelioma carries a dismal prognosis with a median survival of 5 months. Epidemiology
Medulloepithelioma most commonly affect children between 6 months and 5 years; rarely, this tumour may occur congenitally or beyond this age range. Incidence is equal in males and females. References


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