Another possibility that can explain the pain is pericarditis. It causes chest pain aggravated by laughing yawning and deep breathing and also causes radiation of pain to arms. Again an EKG, heat echo and chest X-ray is required. I think you should discuss these possibilities with your doctor.
This is due to the confering of such atypia to progeny-cells further down the lineage of that cell type. The term atypia is also used dermatologically and can be a precursor to melanoma. The related concept of dysplasia refers to an abnormality of development, and includes abnormalities on larger, histopathologic, scales.
Quick Answer. Atypical cells, the presence of which is sometimes called dysplasia, have a number of causes that range from infection and/or inflammation to normal aging. Atypical cells usually revert back into normal cells once the cause is identified and treated.