Histology Course S IX 14 Department of Pathology, University of Zurich Histology Course

S IX 14 histiocytoma of skin  HE further information (German) on HiPaKu
  ICD-10: C44.9; ICD-O: 8832/0

36-year-old female, lens-shaped induration of the skin at the calf with intact epidermis and discrete increased pigmentation. Excision.

- Poorly demarcated cluster in the cutis: plump spindle cells without any typical features arranged in a whirl.
- There may also be foam cells, multinucleated giant cells and haemosiderin deposits
- The epidermis is intact and hyperplastic with hyperpigmentation, and is not affected by the lesion.

This is a common form of fibro-histiocytic neoplasia (refer to specimen S IX 15). It is occasionally difficult to tell apart from related aggressive and malignant tumours..