Removal of tissue or suspensions of cells from living patients through a small needle for diagnostic examination.

An abnormal tissue that grows by cellular proliferation more rapidly than normal and continues to grow after the stimuli that initiated the new growth cease.

The entire integrated system of nerve tissue in the body

Nerve cell; conducts electrical signals.

The clinical subspecialty concerned with the diagnostic radiology of diseases of the central nervous system, head, and neck.

Denoting a procedure that does not require insertion of an instrument or device through the skin or a body orifice for diagnosis or treatment.

The clinical discipline concerned with the diagnostic and theraputic uses of radionuclides (an isotope of artificial or natural origin that exhibits radioactivity), excluding the therapeutic use of sealed radiation sources.

The center of the cell containing the genetic information (genes and chromosomes, DNA, etc.).