Fig. 2From: Spontaneous regression of non-small cell lung cancer after biopsy of a mediastinal lymph node metastasis: a case reporta Tissue obtained by biopsy of a right paratracheal lymph node showing metastatic cells of large cell carcinoma. b Immunohistochemical staining showing cytokeratin positivity (KL-1) of tumorous cells within the lymphatic tissueBack to article page