The study of changes in tissues caused by disease. Histopathology is the examination of biological tissues in order to observe the appearance of diseased cells in microscopic detail.
Histopathology is the examination of tissues from the body under a microscope to spot the signs and characteristics of disease. Histology is the study of tissues, and pathology is the study of disease.
So taken together, histopathology literally means the study of tissues as relates to disease. A histopathology report describes the tissue that has been sent for examination and the features of what the cancer looks like under the microscope. A histopathology report is sometimes called a biopsy report or a pathology report.