50. Planocellular carcinoma of the lung

Staining: HE

Organ: Bronchus

Description:

We can see cartilage and respiratory epithelium, so we know that this is a bronchus.

We can divide the slide into 5 “parts”:

• 1 shows normal, healthy respiratory epithelium
• 2 shows goblet cell hyperplasia and basal cell hyperplasia
• 3 shows squamous cell metaplasia
• 4 shows squamous cell dysplasia and carcinoma in situ
• 5, which is the majority of the slide, shows the invasive carcinoma

The carcinoma cells show pleomorphism and mitotic figures and giant cells are present.

Diagnosis: Squamous cell lung carcinoma

Causes:

• Smoking

Theory:

Squamous cell carcinoma in the lung usually occurs centrally, around the hilum. It shows symptoms earlier than adenocarcinomas and large cell carcinomas, which grow peripherally. However, also because of the central location is surgical removal of squamous cell carcinomas more difficult than for the peripheral-growing cancers.

In this slide we can see several stages of cancer development, from hyperplasia to metaplasia to dysplasia to cancer.

It can metastasize into pericardium, mediastinum, aorta and even the heart.

Overview of the slide, with the 5 parts

From part 1. Shows normal, healthy respiratory epithelium.

From part 2. Shows goblet cell and basal cell hyperplasia. Basal cells are the cells that are in contact with the basement membrane.

From part 3. Shows the border between respiratory epithelium and squamous metaplasia (upper half of the slide). You can see that the squamous metaplasia doesn’t have kinocilia.

From part 4. Shows squamous cell dysplasia and carcinoma in situ.

From part 5. Shows how the cancer has spread even beyond the cartilage (upper left).

From part 5. Shows pleomorphism (anisocytosis, anisochromasia, anisonucleosis), mitotic figures and multinucleated giant cells.