Pancreatic Pathology Online
Nonneoplastic Tumor-like lesions ('Pseudotumors') of the Pancreas
tumor-like lesions ("pseudotumors") of the pancreas include cystic and
In the pancreas, a variety of non-neoplastic conditions may form solid masses that may mimic cancer.
Up to 5% of pancreatectomies performed with the preoperative clinical diagnosis of carcinoma will prove to be non-neoplastic by pathologic examination.
Chronic inflammatory lesions are the leading cause of this phenomenon ("pseudotumoral pancreatitis"), and among these, autoimmune and paraduodenal pancreatitides are most important.
Pseudolymphoma forms well-defined nodules composed of hyperplastic lymphoid tissue. Rarely, foreign-body deposits, granulomatous inflammations (such as sarcoidosis or tuberculosis), and congenital lesions may form tumoral lesions.
Nonspecific terms such as "inflammatory pseudotumor" should be avoided, and every attempt should be made to classify a "pseudotumor" into a more specific diagnostic category.
Pathology of Pancreatic Hamartoma:
Diagram of Pancreatic Hamartoma
Nonneoplastic tumour-like lesions ("pseudotumors") or hamartoma of the pancreas include cystic and noncystic varieties.
Solid pancreatic hamartomas seem to be benign tumor-like lesions, which are found incidentally in healthy middle-aged adults.
These lesions are usually located on head and neck of the pancreas. Occasionally the lesion involve the whole pancreas, resulting in a poor prognosis. Macroscopically, pancreatic hamartomas were well-demarcated tumors with a solid or solid and cystic appearance.
Microscopically, the lesion is well demarcated and is usually and composed of cystic ductal structures set in a inflamed stromal tissue.
In some cases lesion is composed of non-neoplastic, disarranged acinar cells and ducts embedded in a sclerotic stroma with elongated spindle cells, lacking discrete islets.
The tumours consistently lacked concentric elastic fibers in their duct walls, peripheral nerves, and well-formed islets of Langerhans, all of which exist in both the normal and atrophic pancreas.
The stromal spindle cells were immunoreactive for CD34 and CD117.
Distinctive histopathologic findings of pancreatic hamartomas suggesting their "hamartomatous" nature: a study of 9 cases.
Pathology of Paraduodenal Pancreatitis:
Syn: 'groove pancreatitis' ; 'cystic dystrophy of heterotopic pancreas'; para-duodenal wall cyst ; myoadenomatosis ; pancreatic hamartoma of duodenum.
It is a distinct form of chronic pancreatitis occurring predominantly in and around the duodenal wall (near the minor papilla) has been.
The patients are usually males, 40-50 years old.
There is history of excessive alcohol intake.
The lesion is often centered in the region of minor papilla and the adjacent pancreas, which suggests that an anatomic variation of the ductal system may render this area particularly susceptible to the effects of alcoholic injury.
The myo-adenomatoid and cystic changes on the duodenal wall may represent changes related to a localized recurrent pancreatitis.
These are some of the characterisitic features:
- The duodenal wall contains dilated ducts, some with inspissated secretions, and pseudocystic changes.
- The adjacent stromal reactions include hypercellular granulation tissue formation, foreign-body type giant cell reaction engulfing mucoprotein material, and myofibroblastic proliferation.
- Brunner's gland hyperplasia is present.
- There is dense myoid stromal proliferation, with intervening rounded lobules of pancreatic acinar tissue.
The histologic picture resembles "myoadenomatosis," "pancreatic hamartoma," or even leiomyoma in some cases.
- Fibrosis is noted in the adjacent pancreas and soft tissue, especially in the "groove" area (between the pancreas, common bile duct and duodenum), including the region around the common bile duct.
of Accessory Spleen:
Diagram of Accessory spleen
Accessory spleens may be found in 10-15% of the population and most of them are usually located at or near the splenic hilum. Only in 1-2% they are located in the pancreatic tail.
An accessory spleen usually present as a mass in the tail of the pancreas and mimic a neoplasm.
The clinical and radiological differential diagnosis included pancreatic mucinous cystic neoplasm, pancreatic endocrine neoplasm, solid pseudopapillary tumor, ductal adenocarcinoma, and metastasis.
Microscopic examination show heterotopic splenic tissue.
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