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.
Epithelial dysplasia consists of an expansion of immature cells (such as cells of the ectoderm), with a corresponding decrease in the number and location of mature cells. Dysplasia is often indicative of an early neoplastic process. The term dysplasia is typically used when the cellular abnormality is restricted to the originating tissue, as in the case of an early, in-situ neoplasm.