Pathology histology - Colon cancer

Pathology histology

Normal colon

Normal colon - Circular muscle (inner layer)

Normal colon - Crypt

• Crypt = Tubular gland located in the mucosa

• Lined by goblet cells

Normal colon - Enterocyte

Normal colon - Enteroendocrine cell

Normal colon - Goblet cell

Normal colon - Lamina propria

• Contains mainly immune cells

Normal colon - Lympho-glandular complex

• Normal numbers of immune cells (mainly lymphocytes)

Normal colon - Mucosa

Normal colon - Submucosa

Normal colon - Muscularis externa

Normal colon - Muscularis mucosae

Normal colon - Serosa

• Adipose tissue

Well differentiated colon adenocarcinoma

Gland-like structures at wrong location in well differentiated colon adenocarcinoma

Well differentiated colon adenocarcinoma - Mucosa area

Well differentiated colon adenocarcinoma - Muscularis externa layers

Well differentiated colon adenocarcinoma - Submucosa area

Well differentiated colon adenocarcinoma - Tumour cells

• Nuclei on different levels (not in a row at the bottom of the cells as in normal crypts)

Well differentiated colon adenocarcinoma

• Different sized, closely bound gland-like tubule/crypts

• Cell debris in the lumen of the glands (necrotic cell remains mixed with inflammatory cells ) - can be a sign of relative lability of the cancer cells and/or be caused by ischaemia

• No lamina propria between, located very close to each other - Pushed together, not growing in a normal way

Well differentiated colon adenocarcinoma - Cylindrical epithelial cells of cancer glands

• Irregular structure

• Sometimes form several layers (pseudo stratified) due to compression

• Densely packed

• Polymorphic

• Varied sizes and configurations

• Relatively large nuclei and hyperchromatic

• The mucin level in the cytoplasm is severely reduced compared to normal

• Mitosis is frequent

• Prominent nuceolus

• Not all nuclei is not at the bottom of the cell as they are normally - Nuclei are not arranged in a straight line

Superficial growing colon adenocarcinoma

• On the “right” side of the muscularis mucosa

Invasive colon adenocarcinoma

• On the “wrong” side of muscularis mucosa

Well differentiated colon adenocarcinoma - Invasive cancer glandular structures in submucosa

• Not a good prognosis

Well differentiated colon adenocarcinoma - Large groups of invasive cancer cells on wrong side of muscularis externa

• Large clusters of cancer structures

• Forming into glandular structures

• Large nuclei

• Varied location of nuclei

• Tumour has infiltrated all the walls of the intestine, reached the fat tissue and also the muscle tissue here to some extend

Why is all of these images diagnosed as well differentiated colon adenocarcinoma and not poorly differentiated?

• Even though there are cancer cells present that are morphologically different from normal, they are still forming some kind of tubular structure (not the normal shape, but still there) → Well differentiated

• Morphology gives us an indication of the likely behaviour of this cancer

• Good sign, but unfortunately it has spread through the intestinal wall

Poorly differentiated colon adenocarcinoma areas

Lymph node - No signs of metastasis

• Looks normal

• No cancer cells can be identified → Positive sign

• Capsule, normal follicular structure

Poorly differentiated colon adenocarcinoma - Mucosa

Poorly differentiated colon adenocarcinoma - Muscularis externa

Poorly differentiated colon adenocarcinoma - Necrosis in tumour

Poorly differentiated colon adenocarcinoma - Serosa

• The serosa is facing the peritoneal cavity

• Adipose tissue on the other side of the muscularis externa

Poorly differentiated colon adenocarcinoma - Serial surface

• A bit damaged during surgery

• No apparent visible mesothelium

Poorly differentiated colon adenocarcinoma - Cancer cells

• Not arranged in any particular pattern (no crypt or glandular-like structures) → poorly differentiated (little to no resemblance of normal structure) → worse prognosis

• Mitosis can be seen