Medulloblastomas: Medulloblastomas (PNETs) are the most common malignant brain tumor in children (20% of all pediatric tumors) and usually occur in children between the ages of 4 and 10 years. Medulloblastomas occur more often in boys than in girls.
Acanthocyte (from the Greek word á¼ÎºÎ±Î½Î¸Î± acantha, meaning 'thorn'), in human biology and medicine, refers to a form of red blood cell that has a spiked cell membrane, due to abnormal thorny projections. A similar term is spur cells.canthocytosis can be seen in: Acute or Chronic Anemia, Hepatitis A,B,C; Hepatorenal syndrome, Hypopitutarism, Malabsorption Syndromes, Malnutrition In malnourishment, such as anorexia nervosa and cystic fibrosis, acanthocytosis remits with resolution of the nutritional deficiency.
Melanocytes are the cells that synthesize pigment. Through a series of enzymatic reactions these cells efficiently produce melanin pigment that determines skin color. Once it is formed, melanin is packaged into tiny vesicles called melanosomes. The melanocyte has tiny tentacles that it uses to transfer melanosomes to other skin cells. It is interesting to note that dark-skinned patients do not have more melanocytes but instead have melanocytes with more pigment producing power.