Solid and cystic pancreatic tumors. Clinical, histochemical, and electron microscopic features in ten cases

Abstract

Ten cases of the rare solid and cystic pancreatic tumors are presented. All except one occurred in young women (mean age, 25 +/- 9.2 years). The large neoplasms were evenly distributed across the pancreas; in one case, metastasis occurred; all other cases were free from disease after complete resection. Histologic hallmarks of solid and cystic neoplasms were papillary growth, large intracytoplasmic granules, and immunoreactivity with alpha 1-antitrypsin, alpha 1-antichymotrypsin, phospholipase A2, and neuroendocrine markers (neuron-specific enolase [NSE], synaptophysin). This suggests both endocrine as well as exocrine differentiation.

Nonductal neoplasms of the pancreas

“…169,170,173,175,178 Most cases are quite large at diagnosis (mean diameter of 9-10 cm), although with the increased use of crosssection imaging techniques, more cases are being diagnosed when less than 5 cm. 179,180 Grossly, solidpseudopapillary neoplasms appear to be circumscribed or even partially encapsulated.…”

“…Solid sheets of uniform polygonal cells are separated into nests by abundant capillarysized vessels (Figure 18). 178,179,181,182 There is no true lumen formation. The cells are relatively discohesive, and in areas away from the vessels, cell drop away, leaving a ragged cuff of neoplastic cells clinging to the blood vessels; this results in the characteristic pseudopapillae (Figure 19).…”

“…Most solid-pseudopapillary neoplasms stain for vimentin, CD10, neuron-specific enolase, CD56, progesterone receptors, and a-1-antitrypsin ( Figure 21), 169,178,182,[184][185][186][187][188] and the pattern of staining for the last marker parallels the distribution of the hyaline globules. The neoplasms variably express synaptophysin and cytokeratins 178,187 and are consistently negative for chromogranin, ductal markers (glycoproteins), and acinar markers (trypsin and chymotrypsin).…”

“…The neoplasms variably express synaptophysin and cytokeratins 178,187 and are consistently negative for chromogranin, ductal markers (glycoproteins), and acinar markers (trypsin and chymotrypsin). Immunolabeling for b-catenin demonstrates abnormal nuclear labeling in 490% of the tumors, 83,182,189 and 75% also express cyclin D1.…”

“…178,184,[191][192][193][194] The neoplastic cells usually contain numerous mitochondria, abundant rough endoplasmic reticulum, and some annulate lamellae. 184,191,193,195 Most cases also have large (500-3000 nm) membrane-bound electron dense granules that contain internal granular and membranous debris, resembling the contents of complex secondary lysosomes.…”