As a pathologist, I’m used to people thinking that my job mainly involves dealing with death. But nothing could be further from the truth. That is why I and many of my colleagues are so dismayed by changes introduced during the coronavirus epidemic which mean that pathology has not been able to play the role that it should have in helping to understand this new disease.
The word ‘pathology’ tends to conjure up images of body bags, mortuaries and murder investigations. ‘Ho ho,’ people say, ‘your patients can’t answer back.’ They imagine days spent trudging across fields to reach murder scenes, Silent Witness-style, and nights sifting through arcane evidence to catch the perpetrators. And a rare type of pathologist — the forensic pathologist — does indeed do that.
Most pathologists, though, spend the majority of their careers looking after the living. After all, pathology is the study of disease, and the whole point of knowing about diseases is to inform our approaches to preventing and treating them.
There are four main types of pathologist. Microbiologists specialise in the study of infectious diseases — a subtype is the virologist, in particular demand at the moment. Chemical pathologists are experts in the liquid parts of the blood; they analyse the endless samples that pour into path labs day and night, looking for changes in chemicals and hormones that indicate disease. Haematologists are experts in diseases of the blood cells, the red cells and white cells that can cause problems such as anaemia or leukaemia.
And then there is my own speciality of histopathology, or cellular pathology. We are experts in analysing changes in the fabric of our bodies that result from disease. Many diseases affect our tissues in ways that can be seen down the microscope, allowing them to be accurately diagnosed and monitored, particularly tumours and inflammations. Every time a biopsy or surgical sample is taken, it comes to the histopathology lab to be examined. Histopathology is often regarded as a ‘gold standard’ for diagnosis of diseases that change tissue structure. A clinical examination or X-ray may suggest that a tumour or fibrosis of the lung, say, is present, but you need to examine a tissue sample microscopically to be sure that it’s really there, what type it is, and how advanced. Tissue can also be examined genetically to look for the presence of infectious agents or cellular receptors that may determine how deadly it is.