Table 3.
Pathology of the Major Neoplasms of the Pancreas
| Tumor type | Gross | Microscopy | Clinical Importance |
|---|---|---|---|
| Acinar cell carcinoma | Large soft fleshy solid masses | Pyramidal cells neoplastic cells form small lumina. Expression of digestive enzymes can be demonstrated by immunolabeling. | Rare fully malignant neoplasm. 15% associated with metastatic fat necrosis caused by the release of digestive enzymes into the blood stream. |
| Invasive ductal adenocarcinoma | Poorlydefined firm solid infiltrative masses | The neoplastic cells form glands and infiltrate tissues. Vascular and perineural invasion are common. Associated with a dense desmoplasticstroma. | Most common type of pancreatic cancer. Very poor prognosis. |
| Intraductal papillary mucinous neoplasm (IPMN) | Cystic tumors that arise in the larger pancreatic ducts. Finger-like papillae of neoplastic cells project into mucin-filled ducts | Papillae lined by mucin-producing neoplastic cells with varying degrees of dysplasia. | IPMNs are detectable and curable non-invasive precursors to invasive pancreatic cancer. The challenge is not to over treat low-grade IPMNs. |
| Mucinous cystic neoplasm (MCN) | Cystic neoplasm that almost always arises in the tail of the pancreas. Cysts filled with mucin. | Mucin-producing neoplastic epithelium resting on ovarian-type stroma. | Can progress to invasive cancer if untreated. |
| Pancreatic intraepithelial neoplasia (PanIN) | Microscopic lesions | Noninvasive epithelial proliferations in the smaller pancreatic ducts. Associated with lobulocentric atrophy. | PanINs are a curable noninvasive precursor to invasive pancreatic cancer, but most are too small to detect. |
| Pancreatoblastoma | Large soft solid masses | Similar to acinar carcinoma but also have squamoid nests. | More common in children than adults. |
| Pancreatic neuroendocrine tumor (PanNET) | Well-demarcated and soft solid masses | Nests and trabecullae of relatively uniform cells with “salt and pepper” chromatin. Expression of neuroendocrine markers and hormones can be demonstrated by immunolabeling. | Some arise in the setting of a familial genetic syndrome. Aberrant hormone production can cause clinical syndromes. Fully malignant, with a 45% 10-year survival rate |
| Serous cystadenoma | Cystic neoplasms with thin septa, and straw-colored fluid. Often have a central scar. | Clear cuboidal cells without atypia line cysts. | Virtually always benign. |
| Solid-pseudopapillary neoplasm | Solid masses that undergo cystic change caused by hemorrhage and necrosis | Poorly cohesive cells surround delicate blood vessels. | Most arise in young women. Low-grade malignant neoplasms. |
| Variants of ductal carcinoma (adenosquamous, colloid, medullary, undifferentiated, etc.) | Most are solid | Varies based on tumor type. | Can be clinically important to recognize. |
IPMN=intraductal papillary mucinous neoplasm; MCN=mucinous cystic neoplasm; PanIN=pancreatic intraepithelial neoplasia; PanNET=pancreatic neuroendocrine tumor; SCN=serous cystic neoplasm; SPN=solid-pseudopapillary neoplasm