Figure 4
From: Minute ampullary carcinoid tumor with lymph node metastases: a case report and review of literature
(a) The resected specimen contains a small yellowish submucosal tumor (approximately 7 mm in diameter) located at the ampulla of Vater (arrow). (b) Monotonous tumor cells with small round nuclei are seen (hematoxylin and eosin staining, × 400). (c) Carcinoid tumor cells within a peripancreatic lymph node (× 200). (d) The tumor cells are positive for synaptophysin, a neuroendocrine marker (× 40). (e) Endolymphatic tumor emboli are shown by staining with D2-40 antibody (× 400). (f) Positive staining for MIB-1 antibody is seen in approximately 3.2% of the tumor cell nuclei (× 400).