Multinucleated giant cell containing an asteroid, microscopy.

This image depicts a section of a cell block prepared from a fine needle biopsy of an axillary (armpit) lymph node in a patient who had previously had breast surgery. In the middle of the image a multinucleated giant cell stained purple can be seen. The many nuclei of the cell are shown in dark purple. Giant cells are a fusion of multiple epitheloid cells, a type of immune cell. The cell contains an asteroid which is a star-like structure that forms in some giant cells through fusion and rearrangement of the cell structural components called microtubules. The asteroid can be seen in the middle of the giant cell, in the centre of the image. Asteroid bodies are usually described in reference to sarcoidosis, a relatively rare condition which causes clumps of cells called granulomas. However, asteroid bodies are actually more frequently encountered in giant cells formed in reaction to foreign material such as suture. Horizontal image width is 215 micrometers.