Case 73: Reactive lymphoid hyperplasia

This 73 year old man present with an enlarged lymph node in the left submandibular region. Involvement of the node by metastatic carcinoma or lymphoma was considered the most likely possibility clinically and a lymph node biopsy was performed.

The biopsy specimen consisted of a lymph node measuring 1.6 cm in maximum dimension. The lymph node specimen is not available nor is there a photograph.

Microscopic pathology

Macroscopic examination of the slide shows 3 rounded portions of deep blue tissue. Close inspection reveals numerous paler grey-blue zones 1-2 mm in diameter.

Examination under the microscope shows preservation of the normal nodal architecture. The cortex has been significantly expanded by numerous, variably sized reactive germinal centres (1), (2). A mantle of small lymphocytes (1), (2) surrounds each germinal centre. The paracortex is compressed and contains predominantly small lymphocytes.

Normal lymphatic tissues

Click on any hyperlink text in the slide description above to take you to a microscopic view that illustrates the point. The picture will be resized to fill your screen. You can then enlarge the picture to full size by clicking anywhere within it. Or you can click on one of the pictures below for the same result. Press the left browser arrow to return here. Where there are numbers in brackets, these refer to the numbers of the pictures below.

Micro 1 of 2

Micro 2 of 2

Test yourself on the pictures of this case - Link to the lymphatic system test pictures

Commentary

This is an example of the follicular type of reactive lymphoid hyperplasia. This is indicative of a B cell response to an immune stimulus. In many cases the features are non-specific (as in this case) and the aetiology is obscure.

Lymph node biopsies should be sent urgently and fresh to the Pathology Laboratory in a sterile container. On arrival in the laboratory a pathologist will examine the removed node. Depending on the clinical setting and the macroscopic appearance of the node, tissue will be submitted for microbiological culture, cell marker studies, electron microscopy and routine processing.

Learning objectives

1. Recognise the key features of lymphoid hyperplasia so you can distinguish it from a neoplastic proliferation
2. Know the importance of fresh material for laboratory diagnosis