Figure 3: (A) Hematoxylin-eosin (H-E) staining of the biopsied neck lymph nodes shows malignant cell proliferation with enlarged nuclei and clear eosinophilic cell bodies. (B) The immunostaining with thyroid transcription factor 1 (TTF-1) is positive. (C) The cytology of cerebrospinal fluid with papanicolaou staining is compatible with metastatic adenocarcinoma.