Pathology & Histology

Here is a clinical scenario: a patient comes to your office for a routine examination. While examining the skin, you notice an ill-defined and oddly-colored brown spot on the patient’s back. Or perhaps while palpating the thyroid gland, you palpate something that doesn’t feel quite right. What is the next step in this patient’s care? If you thought to perform a biopsy, you’d be correct. Indeed, to derive insights from what a patient is suffering from, clinicians obtain a sample of tissue via biopsy from the suspect organ for the tissue to be studied histologically.

Biopsy
Origin: Greek, bios (life) + opsia (a sight)
A sight of life

Histology
Origin: Greek, histos (web/tissue) + logos
The study of tissue

This tissue can initially be examined grossly [L., grossus (thick/coarse)], i.e., by the naked eye, but clinicians often require insights from a pathologist to more completely characterize and understand the tissue they obtained. What does a pathologist study? Let’s take a look:

Pathology
Origin: Greek, pathos (suffering) + logos (word, taken to mean “study of”)
The study of suffering

This is a very generalized definition of pathology (which is absolutely wonderful to me), but let me offer my own comprehensive/digestible definition of pathology. Pathology is the molecular, histological, and gross study of disease processes and their clinical manifestations. Thus, staying true to its etymology, pathology is the systematic and scientific study of suffering. There are four main areas that pathologists explore to better understand disease: aetiology, pathogenesis, morphological changes, and clinical manifestations.

spitz papillary

Left: Spitz nevus (mole). Right: papillary thryoid carcinoma

Aetiology
Origin: Greek, aitos (cause) + logos
The study of the cause of a disease

Pathogenesis
Origin: Greek, pathos + genesis (origin/source)
The origin and development of disease

If all goes well, the pathologist will generate a diagnosis and a prognosis regarding the patient’s condition, and the clinician or the surgeon will proceed accordingly.

Diagnosis
Origin: Greek, dia– (through) + gignoskein (to know) + –osis (condition of)
A condition of knowing through, i.e., a distinguishing

Prognosis
Origin: Greek, pro- (for/before) + gignoskein + –osis
A condition of foreknowledge, i.e., the likely outcome

What tools does a pathologist use to actually study the tissue in question and generate a diagnosis? You’ll have to stay tuned to find out!

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