Challenging Lung Carcinoma with Coexistent ΔNp63/p40 and Thyroid Transcription Factor-1 Labeling Within the Same Individual Tumor Cells

We herein report on an unusual instance of non–small-cell lung carcinoma (NSCLC) with double squamous/basal-like and glandular differentiation within the same individual tumor cells as documented in a biopsy sample by means of immunohistochemistry (IHC), electron microscopy (EM), and molecular investigation. Coexistence of glandular and squamous traits within the same tumor cells has previously been described in NSCLC using EM1 to testify the possibility of "amphicrine" biphenotypic tumors as an extreme consequence of intratumor heterogeneity in lung cancer.