Department of Pathology, University of Oklahoma Health Sciences Center

NeuroTest Question #65 Next question Previous question

Answer: Dense core (neurosecretory) granules  Level of difficulty: 3 NeuroTest NeuroLearn NeuroHelp

Discussion: 

• Dense core (neurosecretory) granules: They are membrane bound vacuoles with a core of electron dense material (Þ) . They can be normally found in the presynaptic bulbs. The smaller ones are 40-80 nm in diameter and the larger ones are 100-150 nm in diameter. This electron micrograph is taken from a pituitary adenoma of which dense core granule is a diagnostic feature. Dense core granules in pituitary adenoma can vary from 150 to 1,500 nm in diameter.
• Mitochondria: They are far, far larger then dense core granules and is illustrated by the red arrow (Þ) in this photograph. Note that the fixation is not optimal and there is a mild, artifactual dilatation of the mitochondria.
• Desmosome: They are membrane junctional complex that are found in epithelial cells and tumors with epithelial cell phenotype such as pituitary adenoma and a variety of carcinomas. They are illustrated by the blue arrow here (Þ) .
• Neutral fat (lipid): They are not membrane bound nor contain electron dense core. In addition, they are much larger in size.
• Cilia: There is no well defined cilia in this photomicrograph.

Comment: KarMing-Fung@ouhsc.edu