Solid Pseudopapillary Neoplasm of the Pancreas with High-Grade Malignant Transformation Involving p16-RB Pathway Alterations

Figure 2

Histological and immunohistochemical findings of the low-grade pseudopapillary areas of the pancreatic tumour (×400). (a) Conventional pseudopapillary structures composed of uniform, poorly cohesive monomorphic cells and fibrovascular stalks. Mitosis was not prominent. (b) Nuclear and cytoplasmic immunohistochemical expression of β-catenin. (c) Ki-67 index: 6%. (d) Normal nuclear staining for RB protein. (e) Heterogeneous staining for p16 protein.

(a)

(b)

(c)

(d)

(e)