29. Sarcoidosis in lymph node

Staining: HE

Overview of the slide

Organ: Lymph node

Description:

The whole slide is made up of mainly eosinophilic parts, with some basophilic tissue in between. Black pigment can be seen in some regions.

Diagnosis: Sarcoidosis

Causes:

• Unknown cause

Theory:

See also macropreparation 32 and slide 30. The basophilic tissue is the remnant on the normal lymphoid tissue that lymph nodes are comprised of. The eosinophilic rest of the slide is made up of granulomas. These granulomas are “hard” because they have no necrotic centre. Not many giant cells can be seen. These granulomas are mostly made up of epithelioid cells. We can know that this lymph node is from the lung because we can see anthracosis.

Anthracosis

The dark spots are lymphoid tissue. The eosinophilic spots are the granulomas.

Epithelioid granulomas