Pigmented PanNET : Gross Pathology

Comments:
Pigmented "black" neuroendocrine tumor of pancreas appears dark brown/black grossly due to cytoplasmic granules of lipofuscin pigment. The tumor may mimic metastatic melanoma at first glance; however, melanocytic markers are negative. See microscopic appearance here.

Image courtesy of: University of Colorado Dept. of Pathology (@CU_Pathology); used with permission.