Figure 3: Tumour-associated slanDCs are detectable only in M-TDLN.

(a) Graph shows the frequency of carcinoma cases containing DC subsets and macrophages. Data have been obtained by scoring multi-tumour TMA sections stained for CD68, CD11c, CD163, CD1a and DD2 (n=3). (b) Graph shows the frequency of M-TDLN cases from different primary tumours containing slanDCs (GE, genital; GI, gastrointestinal; UR, urinary; LU, lung; H&N, head and neck; BR, breast; SK, skin). Data have been obtained by analysing a cohort of eighty M-TDLN on sections stained for DD2. (c–h) Sections are from M-TDLN stained as indicated. In M-TDLN, numerous slanDCs commonly line the nodal metastasis (c), while in cases with low tumour burden (d) slanDCs are found in close contact with dispersed single tumour cells. Double immunohistochemistry illustrates co-expression of CD68 (e) and CD11c (f) by DD2⁺ slanDCs. (g,h) Comparative analysis of a slanDC-rich M-TDLN (g) with its matched primary carcinoma (h), the latter completely devoid of slanDCs in the surrounding tumour stroma. Sections are counterstained with Meyer’s haematoxylin. Original magnifications: 40X (c, scale bar, 500 μm); 600X (d–f, scale bar, 33 μm); 100X (g,h, scale bar, 200 micron). T, tumour cells.