In Indonesia, the laboratory can be described as a place occupied by three things: machines, analysts, and clinical pathologists. Machines are contraptions doing all the automated laboratory examinations, analysts are people operating the machines and performing the manual examinations, while clinical pathologists are medical doctors who click on the computer mouse. This unfunny role of clinical pathologists in the world of medicine has been a subject of ridicule and mockery. The machines are perfect and the analysts are experts, so why does the world of medicine require an extra person to authorize something that doesn’t need to be authorized? Even if some kind of authorization is needed, isn’t it best be done by the clinicians who treat and know the patients well, thus enabling them to directly compare the laboratory results with the real conditions?
It’s no wonder then to have a clinical pathologist’s protest in a seminar painfully dismissed by an internist. The protest was the fact that most clinicians do not include the patient’s diagnosis in the laboratory form, making it hard for clinical pathologists to produce a clinical interpretation. The dismissal was that a clinical pathologist’s interpretation was actually not needed at all. “We will make the interpretation ourselves,” said the internist sharply. Ouch... It seemed like there’s no use to have a clinical pathologist around.
Such notions proved to be personally troublesome, especially when I realized I had already enrolled in a school to be one. Bigger questions came up in mind. What are clinical pathologists really? What are they supposed to be doing? Is it true that they do not have a role at all in the world of medicine? And if they do, must they first be medical doctors?
I pondered as I went along. After about two years living in the environment, here are a couple of things I’ve noted from teachers, friends, and my own experience.
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A clinical pathologist is someone who practices clinical pathology. Clinical pathology on the other hand, can be simply defined as a study of diseases and their diagnosis based on laboratory analysis of specimens, mostly blood and body fluids. Compared to another major division of pathology, the anatomical pathology, clinical pathology deals with something much more dynamic. This means that the specimens and what they represent are always something that is in a rapid balance, whether it is a substance, cells, or even microorganisms. This is not the case with anatomical pathology, which usually deals with the structure of tissues.
Now, the question remains whether a clinical pathologist, considering his extensive use of machines and other people’s expertise (analysts), can be abolished entirely. Should clinicians just give the samples to the machines and analysts, receive the plain results, and interpret them themselves? The answer is yes and no.
When I say yes, it is because I believe, contradictory to most clinical pathologists, clinical interpretations are solely the right of clinicians. Clinical pathologists do not see the patients when they were first admitted, follow their progress everyday, nor execute any kind of managements. Those things are done by clinicians. They know the patients well. Hence, their interpretations are the valid ones and any clinical interpretation made by clinical pathologists, regardless the possibility that it is also made based on the diagnosis written in the laboratory form, are vague and pointless.
But I also say no to the idea of erasing the profession because clinical pathologists do have some roles. Between the generation of results and the clinical interpretation, there is an unsurprising phase of authorization or infamously known as the "mouse clicking". The surprising part, however, is the fact that this phase is really needed and important.
Measuring substances, cells, or microorganisms in a human body is a tricky business. When all you have is pint of blood along a bunch of chemicals and you are asked how much glucose is in it, you’re facing a not so easy job. Proving the result you get is true is not less difficult. How do you know for sure that the glucose concentration is truly 171 mg/dL? Almost always, machines and manual examinations will give different results regardless the same basic principle being used. Even the same machine is unlikely to produce the same result over the same sample. Various factors can affect laboratory examinations in every step, from the pre-analytical to the post-analytical phase. There are also underlying aspects of uncertainty, precision, accuracy, linearity, and phenomena that need to be counted for. If a control run shows 9 consecutive values below last month mean, what needs to be done? What if it shows 10 values instead of 9? What do we do when we have a leukocyte number of 110,000/μL and the machine’s linearity is 0-100,000? What is required when we have a platelet count of 650,000/ μL with very low mean erythrocyte values? Those are several questions that a clinical pathologist has to deal everyday, and all of them are just from the technical point of view.
From the medical point of view, there are aspects of the patients that need to be considered. This point of view is special because although it is medical, it basically stems from the technical one, making it something unique and almost exclusive to clinical pathology. We can take an example on how low density cholesterol (LDL-C) is measured. One of the most routinely available methods to measure LDL-C is an indirect one, using a formula that involves three serum concentrations of substances, one of which is triglyceride. When we have all the concentrations needed, all we have to do is put them in the formula and calculate the concentration of LDL-C from it. The formula, however, is based on an assumption that in humans, concentration of triglyceride is always five times the concentration of very low density lipoprotein cholesterol (VLDL-C). Whenever this is not the case, LDL-C measurement using this method will only yield false result. Thus, in people with conditions like dyslipidemia type IIb and IV (higher concentration of VLDL-C) or diabetes (higher triglyceride), this formula can no longer be applied correctly unless some act of precaution has been done. This is also the reason why when we use the formula, the patient is required to fast. Recent meals will increase triglyceride concentration variably and considerably, rendering the formula useless. So basically, it is clear that in order for a laboratory examination to work, it's essential to put some consideration into the human body itself.
To this point, we can imagine that clinical pathology provides a bridge between technical methods and the state of human body. Machines may produce results and a decision that a patient has hypercholesterolemia needing gradual correction may be the right of clinicians, but supervision of the machines and the decision that a 126 mg/dL LDL-C concentration of a sample is truly the concentration a patient has in his blood can only be taken by a clinical pathologist. Again, machines may produce results and a diagnosis of diabetes mellitus may be the right of clinicians, but the decision that a 171 mg/dL glucose concentration of a sample is truly the real concentration a patient has can only be taken by a clinical pathologist. Laboratory results are not that easy to validate and it is the job of a clinical pathologist to make sure that the results are the actual thing.
In the same time, the above paragraphs can also explain why a clinical pathologist needs a clinical diagnosis to be written in the laboratory form. It isn’t for making up clinical interpretations as suggested early in this article when the internist dismissed the protest. It is instead for validation. It acts as a source of information on the patient’s condition, enabling a clinical pathologist to put what’s happening in the patient’s body into account when validating a laboratory result. For instance, a clinical pathologist will be faster convinced to validate a platelet count of 5,000/μL when the diagnosis is aplastic anemia.
The question regarding whether a clinical pathologist must be a medical doctor can also be answered. Only a medical doctor has the education and training about the inside of the human body, and thus can offer an integration between the technical part of a laboratory examination and the medical part of a patient’s conditions. An example is when a sample of cerebrospinal fluid is sent to the laboratory to be analyzed. An analyst may be able to perform the required examinations, but only a clinical pathologist knows what examination needs to be done first if the sample is way below the amount needed (cell identification over protein tests, or Indian ink test over cell identification, etc.). This is possible because a clinical pathologist possesses a general idea of what the clinician actually needs when he sent the sample in the first place. The difference between an analyst and a clinical pathologist can also be understood more clearly when we compare the nature of payments for both jobs. An analyst is only responsible in technicality and so he is paid by the number of tests. A clinical pathologist, on the other hand, is responsible in technicality and validation of a patient’s results and so he is paid (or should be paid) by the number of patients, just like any other clinicians. By the end of the day, a clinical pathologist is still a medical doctor.
To sum it up, in my opinion a clinical pathologist has five main roles. He is an authorizer, consultant, manager, scholar, and clinical interpreter. The role of an authorizer has been described extensively above. The role of a consultant puts a clinical pathologist as an expert in laboratory examinations. Therefore he can provide his partners (mostly clinicians and researchers) with information on how a test is done, its basic principle, subject preparation, types and amount of sample needed, how to store and transport it, the strengths and weaknesses of a test, its sensitivity and specificity, other tests that are available regarding a clinical diagnosis, and more. The role of a manager is also a task of a clinical pathologist because he leads a unit called the laboratory. It makes him in charge not only in tests, but also in employee affairs, finance, logistics, equipments, improvements, facility and safety, and basically all the things needed to keep a laboratory going. The role of a scholar requires a clinical pathologist to constantly update his knowledge on the latest development in diagnostics and pathology, do researches, and invent new diagnostic procedures. The last role, the clinical interpreter, is somewhat problematic because I have expressed a strong disagreement on the matter. However, I think in some cases a clinical pathologist does face the need to provide some clinical interpretation. For instance, the need to interpret a certain hematology test result as a possible acute myeloid leukemia. Although there is no doubt that clinicians still have the last say, I still think that an extra educated opinion on such a grave matter won’t hurt, especially when the clinician who asked for the test is not a hematologist.
Finally, to answer the primary question, “What are clinical pathologists?” I can say lightly that they are people who delve into the dynamics of the human body and its state of sickness to become measurers of man. Or puzzlingly simply, they are medical doctors who run the laboratory.
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