Granuloma

In medicine (anatomical pathology), a granuloma is a group of epithelioid macrophages surrounded by a lymphocyte cuff. Granulomas are small nodules that are seen in a variety of diseases such as Crohn's disease, tuberculosis, sarcoidosis, berylliosis and syphilis. It is also a feature of Wegener's granulomatosis and Churg-Strauss syndrome, two related autoimmune disorders.

Related Topics:
Medicine - Anatomical pathology - Epithelioid - Macrophage - Lymphocyte - Crohn's disease - Tuberculosis - Sarcoidosis - Berylliosis - Syphilis - Wegener's granulomatosis - Churg-Strauss syndrome - Autoimmune disorder

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Important aspects of granulomas are whether they are caseating or not. Caseation (literally: turning to cheese) is a form of necrosis at the centre of a granuloma and is a feature of the granulomas of tuberculosis.

Related Topics:
Cheese - Necrosis - Tuberculosis

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The tuberculous granuloma (caseating tubercule): central caseous necrosis bordered by giant multinucleated cells (Langhans cells), and surrounded by epithelioid cells aggregates, lymphocytes and fibroblasts. Granulomatous tubercules tend to confluence. Multinucleated giant cell (mature - Langhans type): 50-100 micrometres, numerous small nuclei (over 20) disposed at the periphery of the cell (crown or horseshoe), abundant eosinophilic cytoplasm. It results when activated macrophages merge. Epithelioid cells are activated macrophages resembling epithelial cells: elongated, with finely granular, pale eosinophilic (pink) cytoplasm and central, ovoid nucleus. They have indistinct shape contour and form aggregates. At the periphery are the lymphocytes (T cells) and rare plasma cells and fibroblasts. Caseous necrosis is a central area, amorphous, finely granular, eosinophilic (pink). If recent, it may contain nuclear fragments. The caseum is the result of giant cells and epithelioid cells destruction.

Related Topics:
Caseous necrosis - Langhans - Caseum

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