Neuroimaging - CNS Tumors, Infections & Neurocutaneous Syndromes MCQs

Drop metastasis refers to the spread of tumor cells through the cerebrospinal fluid (CSF) leading to seeding of the leptomeninges along the spinal cord or brain surface. This phenomenon is seen in certain types of brain tumors, particularly those originating in or near the ventricles or meninges. Medulloblastoma (A), Pineal germinoma (B), and Ependymoblastoma (C) are all types of brain tumors that can spread through the CSF and cause drop metastasis. Oligodendroglioma (D), however, typically does not exhibit this pattern of spread. Oligodendrogliomas are more likely to spread locally within the brain rather than through the CSF.

Cect is better to evaluate small bowel tumors

N-Acetyl Aspartate (NAA) Is the higher peak in normal MR Spectroscopy and is indicative of neuronal integrity NAA is reduced in most pathologies except for CANAVANS Disease, which shows elevated NAA peak

The classic form of this disease has the following characteristics: B cells are absent or markedly decreased in the circulation, and serum levels of all classes of immunoglobulins are depressed. Pre B cells, which express the B-lineage marker CD19 but not membrane Ig, are found in normal numbers in the bone marrow. Germinal centers of lymph nodes, peyer's patches, the appendix, and tonsils are underdeveloped. Plasma cells are absent throughout the body. T cell mediated reactions are normal. Reference: Robbins and Cotran Pathologic Basis of Disease, 10 th Edition, Page Number-244.

The idea that angiogenesis is essential for solid tumors to grow to clinically significant sizes provided a powerful impetus for the development of therapeutic agents that block angiogenesis. These agents are now a part of the armamentarium that oncologists use against cancers. A cardinal example is Bevacizumab, a monoclonal antibody that neutralizes VEGF activity and is approved for treatment of multiple cancers. Reference: Robbins and Cotran Pathologic Basis of Disease, 10 th Edition, Page Number-306.