Fig. 4From: Biphasic low-grade nasopharyngeal papillary adenocarcinoma: a case report and literature reviewImmunohistochemical staining of tumor samples. The left side shows spindle cells while the right side shows columnar cells. The tumor was positive for (a) CK7 and (b) thyroid transcription factor-1, and was negative for (c) PAX8 and (d) p40. All magnifications are × 200Back to article page