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 4

Large, cohesive, three-dimensional aggregates of cellular material predominate in the direct smears. These show spheroidal globules of eosinophilic to amphophilic extracellular material with intimately associated small to intermediate sized spindled and epithelioid cells. While appliqueed spindled cells are noted on the spheroids, true intrinsic fibrovascular cores are not identified (Papanicolaou stain, 200X).