Fig. 6.

a In this lymph node with metastatic carcinoma, there is no capsule surrounding the lymphoid tissue that contains tumor. The hilum of the node is towards the left. The edge of the lymphoid tissue with tumor was in smooth continuity with the rest of the node, and this was not interpreted as ENE. b Same case as 6a, but a different lymph node. Again the capsule is ill-defined and the lymphoid tissue in the upper part of the field could be interpreted as extranodal and reactive. The ill-defined periphery and desmoplastic response to tumor in the upper right was interpreted as microscopic extranodal extension. However, this determination and the site of the “external aspect of the capsule” for ENE measurement are both subjective