rather than DC differentiation in which abundant expression of CD1 and CD11c is expected. The exact sublineage of DC involved in HS has not been determined in most instances. The most likely candidates include interdigitating DC in lymphoid tissues and perivascular interstitial DC in other involved tissues. Immunophenotyping and careful morphological assessment should also avoid confusion of HS and MH with the large cell form of cutaneous T cell lymphoma, and poorly differentiated mast cell tumors. List of immunohistological markers for canine histiocytic diseases Cutaneous histiocytoma = Langerhans cells: CD1+, CD11c+, MHCII+, CD86+, E-cad+, Langerin+, CD14-, Thy1- Reactive histiocytosis = Interstitial/dermal dendritic cells: CD1+, CD11b+, CD11c+, MHCII +, CD86+, Thy1+, CD4+, CD14-, E-cad- Histiocytic sarcoma complex = Dendritic cells (interdigitating or perivascular?): CD1+, CD11c+, MHCII+, E-cad-, Thy1-, CD4- Macrophages (for example in haemophagocytic syndrome): CD11d+, CD14+, MHCII+/-, CD1-, CD86-, Thy1-, E-cad-. References External links School of Veterinary Medicine Histiocytic diseases