Tuberculous Lymphadenitis (15) Granuloma Tuberculous Lymphadenitis (15) Tuberculous Lymphadenitis Epithelioid granuloma Langhan’s giant cell Caseous necrosis T.B. of the Lung Sarcoidosis Rhinoscleroma Fungal Granuloma Nodal tissue Extensive caseation

Tuberculous Lymphadenitis (15) Granuloma Tuberculous Lymphadenitis (15) Section in a lymph node showing: Effacement of the normal lymph node architecture and replacement by multiple confleunt (fused) epithelioid granulomas. The granulomas are made up of epithelioid cells, multinucleated Langhan’s giant cells and a mantle of lymphocytes with central areas of pink homogenous structureless caseous necrosis. Langhan’s cells show peripheral horse shoe arrangement of the nuclei.

Tuberculosis of the lung (16) Granuloma Tuberculosis of the lung (16) Tuberculous Lymphadenitis Central caseation T.B. of the Lung Sarcoidosis Rhinoscleroma Tubercle Fungal Granuloma Langhan’s giant cell

Tuberculous of the lung (16) Granuloma Tuberculous of the lung (16) Section in lung showing Multiple scattered rounded tubercles formed of: -Epitheliod cells -Lymphocytes -Langhan’s giant cells With little or no caseation The intervening lung tissue shows compensatory emphysema.

Granuloma Sarcoidosis in lymph node (17) Tuberculous Lymphadenitis Giant cell with Schaumann body Langhan’s giant cell T.B. of the Lung Sarcoidosis Rhinoscleroma Giant cell with Asteroid body Fungal Granuloma Multiple epithelioid granulomas

Sarcoidosis of Lymph Node (17) Granuloma Sarcoidosis of Lymph Node (17) Section in a lymph node showing - Effacement of normal lymph nodal architecture and replacement by multiple discrete epithelioid non caseating granulomas, made up of epithelioid cells and multinucleated giant cells with a mantle of lymphocytes and some fibroblastic proliferation. -The epithelioid cells are oval or rounded with faint eosinophilic cytoplasm and central or eccentric vesicular nuclei and ill defined borders. -The langhan’s cells show peripheral horse shoe arrangement of the nuclei. -Schaumann bodies and asteroids bodies may be present.

Granuloma Rhinoscleroma (18) Squamous epithelium Russel body Tuberculous Lymphadenitis Squamous epithelium Russel body T.B. of the Lung Sarcoidosis Rhinoscleroma Fungal Granuloma Mickulicz cell

Granuloma Rhinoscleroma (18) Section in the nasal mucosa showing Hyperplastic thickened stratified squamous epithelium. The subepithelial tissue is formed of vascular connective tissue which is densely infiltrated by chronic inflammatory cells mainly histiocytes and plasma cells together with lymphocytes and fibroblasts. There are two characteristic cells: Mickulicz cells: large vacuolated with central or eccentric small dark nuclei Russel bodies: oval eosinophilic homogenous structures.

Polymorphs and pus cells Granuloma Fungal Granuloma (6) Tuberculous Lymphadenitis Polymorphs and pus cells skin T.B. of the Lung Sarcoidosis Colonies of fungus Rhinoscleroma Fungal Granuloma

Granuloma Fungal Granuloma (6) Section in the skin showing: Multiple intradermal suppurative granulomas. The central parts of the granulomas show pinkish colonies of a fungus surrounded by polymorphs and pus cells . The peripheral parts of the granulomas show histiocytes, lymphocytes and fibroblasts .