38. Anaplastic carcinoma (brain metastasis)

Staining: HE

Organ: Brain

Description:

We can see four sections. Two of them are necrotic debris where no cell structure is seen, only a soup of necrotic cells with few visible nuclei.

One of the sections shows normal brain parenchyme, where we can see neurons, glial cells, the arachnoid mater and pia mater.

The last section is the one of most interest. Here we can see cells with no organization, but they show significant pleomorphism (anisocytosis, anisonucleosis, anisochromasia), we can see mitotic figures and giant cells.

Diagnosis: Anaplastic brain carcinoma

Causes:

• Unknown

Theory:

The tumor in this case is a carcinoma, meaning that it is a malignant tumor of epithelial cells. However, these cells bear no characteristics of normal epithelial cells (they don’t produce keratin), which means that they are non-differentiated. A non-differentiated malignant tumor is called an anaplasia or anaplastic tumor.

Comparing the cancer cells in this slide to the cancer cells in slide 36, you can see that the cancer cells here show more pleomorphism, which also shows that these cancer cells are non-differentiated.

The large necrotic segments are necrotic parts of the tumor.

Overview of the slide

Necrotic debris. It’s mostly an eosinophilic soup of cell debris with very few nuclei.

Normal, healthy brain parenchyme.

From the tumor. Note the variety of staining of the nuclei (anisochromasia), and the varying sizes of both cells (anisocytosis) and the nuclei (anisonucleosis).

Giant cell