1. Professor Rino Cerio BSc FRCP(Edin.) FRCP(Lon.) FRCPath Departments of Dermatology and Pathology INSTITUTE OF CELLULAR MOLECULAR SCIENCE (School of Medicine & Dentistry) Barts and the Royal London Hospitals Queen Mary’s University of London, UK CASES24-28

2. 30 y.o. Female. Lesion on the thigh. Painful. Suddenly growing pigmented lesion. No trauma. Melanoma?

3. CASE 24 RC Pigmented thigh lesion

9. CASE 24 RC A. Melanoma B. Aneusymal fibrous histiocytoma C. Angiosarcoma D. Kaposi’s sarcoma E. Dermatofibrosarcoma protuberans

10. CASE 24 RC A. Melanoma B. Aneurysmal fibrous histiocytoma C. Angiosarcoma D. Kaposi’s sarcoma E. Dermatofibrosarcoma protuberans

11. Santa Cruz, D.J. and M. Kyriakos, Aneurysmal ("angiomatoid") fibrous histiocytoma of the skin. Cancer, 1981. 47(8): p. 2053-61. Calonje, E. and C.D. Fletcher, Aneurysmal benign fibrous histiocytoma: clinicopathological analysis of 40 cases of a tumour frequently misdiagnosed as a vascular neoplasm. Histopathology, 1995. 26(4): p. 323-31.

13. HISTIOCYTOMA LYMPHOHISTIOCYTIC INFILTRATE REGRESSING ATYPICAL HISTIOCYTOSIS HISTIOCYTOSIS X LANGERHANS’ CELL HISTIOCYTOSIS NON-X HISTIOCYTOSIS MULTICENTRIC RETICULOHISTIOCYTOSIS SELF-HEALING RETICULOHISTIOCYTOSIS MALIGNANT HISTIOCYTOSIS HISTIOCYTIC LYMPHPOMA

18. FACTOR XIIIa

19. CD34 + Type II DD NORMAL HUMAN SKIN

21. Cerio et al 1998 FXIIIa+DD distinct from CD34 Type 2 DD FXIIIa+DD like HLA-DR do not vary with age or sex Unlike CD34 DD which decrease with age especially in hands and feet compared with trunk

24. Wilson Jones, E., R. Cerio, and N.P. Smith, Epithelioid cell histiocytoma: a new entity. Br J Dermatol, 1989. 120(2): p. 185-95.

25. ALTMAN, D.A., B.J. NICKOLOFF, AND D.P. FIVENSON, DIFFERENTIAL EXPRESSION OF FACTOR XIIIA AND CD34 IN CUTANEOUS MESENCHYMAL TUMORS. J CUTAN PATHOL, 1993. 20(2): P. 154-8. Kutzner, H., Expression of the human progenitor cell antigen CD34 (HPCA-1) distinguishes dermatofibrosarcoma protuberans from fibrous histiocytoma in formalin-fixed, paraffin-embedded tissue [see comments]. J Am Acad Dermatol, 1993. 28(4): p. 613-7. Cohen, P.R., R.P. Rapini, and A.I. Farhood, Expression of the human hematopoietic progenitor cell antigen CD34 in vascular and spindle cell tumors [see comments]. J Cutan Pathol, 1993. 20(1): p. 15-20.

26. DERMAL DENDROCYTES Langerhans cells CD1a, CD40, CD80 CD86, Langerin HLA- DR, DP, DQ Dermal dendritic cells DD Type 1FactorXIIIa CD36, CD14 (22%) HLA-DR DD Type 2CD36 ?? Further subsets

27. DENDRITIC CELLS Immunoregulatory cells -Most powerful professional antigen- presenting cell -Activates primary immune response -Down regulates immune response Maintain immune homeostasis Play a key role in immune escape of pathogens and tumours