DERMATOFIBROMA WITH MONSTER CELLS
This is a pseudomalignancy characterized by the presence of large, bizarre, sometimes multinucleated,  cytologically atypical cells within the background of a dermatofibroma. Such cells sometimes contain hemosiderin. The background of ordinary dermatofibroma helps to distinguish these from atypical fibroxanthomas, pleomorphic fibromas, and true spindle cell malignancies.
 
Low power view. The markedly atypical cells are readily apparent at this magnification. The background pathology of a dermatofibroma is best seen in the lower part of the picture.
High power view. Bizarre, cytologically atypical cells are in the background of a dermatofibroma.
Another high power view. Some of the atypical cells have foamy cytoplasm.

Reference:
Tamada S, Ackerman AB: Dermatofibroma with monster cells. Amer J Dermatopathol 1987 Oct;9(5):380-7.


Click on your browser's 'Back' button to go the previous page.