Tumour histology and regressive changes
What tumours look like under the microscope: architecture, differentiation and atypia, what a grade measures, and the regressive changes (necrosis, haemorrhage, cysts, hyalinisation, calcification) that follow when a tumour outgrows its supply.
By the end, you can
- Describe the architectural patterns tumour cells form and relate them to the tissue of origin.
- Explain differentiation and anaplasia, and describe the cytological features of malignant cells.
- Explain what a histological grade measures and why it matters, in general terms.
- Relate a tumour outgrowing its blood supply to necrosis, haemorrhage and ulceration.
- Recognise the later regressive changes, such as cysts, hyalinisation and psammoma bodies, and their consequences.
What it is
The histology of a tumour is how its cells and their arrangement compare with normal tissue. Differentiation is how closely tumour cells resemble their normal counterparts; its loss, with marked cellular abnormality, is anaplasia. Regressive (secondary) changes are degenerative changes inside a tumour, such as necrosis, haemorrhage, cystic change, hyalinisation and calcification, that follow when its blood supply falls short or its cells die.
3 types to tell apart
- Architectural features
- How the cells are arranged: glands, papillae, nests, sheets, cords or fascicles, and whether the border pushes or infiltrates.
- Cytological features
- How individual cells look: the size and shape of their nuclei, chromatin, nucleoli, mitoses and the ratio of nucleus to cytoplasm.
- Regressive changes
- Secondary degeneration within a tumour: necrosis, haemorrhage, cystic and myxoid change, fibrosis, hyalinisation and calcification.
US spelling: tumour → tumor, haemorrhage → hemorrhage.
Normal function
Order in normal tissue
Normal tissue is orderly. In , divide on the ; their daughters mature as they rise through the and flatten into . Every cell sits in a predictable place, oriented the same way as its neighbours (polarity).
Normal are small and uniform in size and shape, with fine, evenly spread chromatin and a small nucleolus. The nucleus takes up a modest share of the cell (a low nuclear-to-cytoplasmic ratio), and mitoses are few, normal in shape and confined to the basal layer.
The tissue also has a matching blood supply: capillaries in the connective tissue lie within diffusion distance of every cell, and new vessels form only when the tissue needs them.
Underlying change · Step 1 of 5
Architecture and differentiation
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Atypia: how malignant cells look
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Grade: measuring how abnormal a tumour is
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Outgrowing the blood supply
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
Regressive changes inside tumours
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 8 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .