Fibrous Extracellular Spheroids in an Endoscopic Ultrasound-Guided Pancreatic Fine Needle Aspiration Correlating to a Gyriform Pancreatic Endocrine Tumor with a Unique Cobblestone Pavement Growth Pattern

Figure 9

(a) Histologic sections from the pancreatectomy specimen confirmed a solid neoplasm with a low power pattern reminiscent of pulmonary alveolar edema or proteinosis with peripheral rims of epithelial cells surrounding eosinophilic spaces (Hematoxylin & eosin, 100X). (b) At greater magnification, the collagenized nature of the eosinophilic cobblestones is apparent with lesional epithelial cells in ribbons between the spheroids (Hematoxylin & eosin, 200X). (c) At highest magnification, the small, bland, tapering and spindled nuclei (black arrow) within the spheroids can be readily distinguished from the lesional epithelial cells between the cobblestones (white arrow) (Hematoxylin & eosin, 600X).

(a)

(b)

(c)