Solid-pseudopapillary Neoplasm of the Pancreas

Abstract

Solid-pseudopapillary neoplasm of the pancreas is a very rare tumor. It most commonly occurs in young women and has unique pathologic features. Previous immunohistochemical studies demonstrated that most solid-pseudopapillary neoplasms were immunoreactive with antibodies directed against vimentin and neuron-specific enolase. Recently, expression of CD10 and CD56 in this tumor has been reported. In this report, we expanded the demographic profile, highlighting 3 cases of solid-pseudopapillary neoplasm of the pancreas that presented in an elderly woman, a young man, and a young woman and further characterized them histologically and immunophenotypically. Grossly, all 3 tumors were well circumscribed and had a variable degree of cystic formation, necrosis, and hemorrhage. Microscopically, these tumors were characterized by a pseudopapillary pattern of epithelioid cells arranged around a delicate fibrovascular core with sheets of bland epithelioid cells filling cystic spaces. Hyaline globules, cholesterol granulomas, and foamy cells were all seen to be common findings. Although these 3 tumors were strongly immunoreactive for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, neuron-specific enolase, CD10, CD56, and progesterone receptor, they demonstrated only variable "positivity" for epithelial membrane antigen and broad-spectrum cytokeratin, but were being consistently nonreactive for synaptophysin, insulin, glucogon, chromogranin A, and estrogen receptor. Interestingly, 2 of the 3 tumors were S-100 protein and melanin A reactive but were nonreactive for HMB45.

Solid pseudopapilllary neoplasm of the pancreas. A clinicopathologic study of 25 cases from Pakistan and review of Literature

“…Synaptophysin positivity ranging from 15% to 20% has also been reported in various studies but often been found to be weak and focal [23,24,26]. Chromogranin A has been reported to be consistently negative in SPNs [23,26,27]. CD56 positivity is consistently seen in SPNs [26,28].…”

Solid pseudopapillary neoplasm of the pancreas: CT imaging features and radiologic-pathologic correlation

“…A single focal eccentric calcification is noted. differentiation (10). These tumors are also often texturally fairly soft; this accounts for the rarity of ductal dilatation and jaundice even for tumors arising in the pancreatic head (4,11).…”

Large, clear cytoplasmic vacuolation

“…We, as well as other observers, have reviewed the immunophenotypic profiles associated with SPN as well as PEN. 5,27,28 Characteristically, SPNs are usually immunoreactive with antibodies directed against vimentin, neuron-specific enolase, a-1 antitrypsin, CD10, CD56, and progesterone receptors. Up to approximately one-third of SPNs may also be immunoreactive for synaptophysin.…”