Type:
Educational Exhibit
Keywords:
Abdomen, Head and neck, Thorax, CT, MR, Ultrasound, Diagnostic procedure, Education and training
Authors:
J. Granadas, J. S. S. Alexandre, S. Ferreira, A. Germano; Lisboa/PT
DOI:
10.26044/ecr2021/C-15294
Background
OCT correspond to a wide subset of lesions composed of cells that display an intense cytoplasmic eosin staining as a consequence of the accumulation of enlarged mitochondria in their cytoplasms. These cells were denominated as “oncocytes”, a term that is derived from the word “onkousthai” in Greek and which means “swollen”.
The pathways involved in the proliferation of mitochondria are not yet known, but the process appears to be triggered by mutations in the nuclear and mitochondrial genes related to the complex 1 of the mitochondrial respiratory chain. This compromises oxidative phosphorylation. As a result, apoptosis is blocked and glycolytic activity increases, which although energetically less efficient, creates intermediate metabolite molecules that are necessary for the creation of new cells. Additionally, a state of pseudo-hypoxia is created, leading to increased hypoxia-inducible factor 1-alpha (HIF-1α) levels and subsequently to increased transcription of vascular endothelial growth factor (VEGF) and other important biological agents. The mentioned changes grant an evolutionary advantage to these cells, and then it is not surprising that OCT are identified in such a great diversity of tissues, such as the salivary glands, the thyroid gland, the adrenal glands, the kidneys, among many others.
OCT may be benign or occasionally show a malignant behavior but they are usually associated with an indolent prognosis. [1]