Clinico-pathological features of cystic pancreatic endocrine neoplasms and a comparison with their solid counterparts

Cystic pancreatic endocrine neoplasms: a distinct tumor type?

BACKGROUND

Cystic pancreatic endocrine neoplasms (CPENs) are considered rare, and their behavior is thought to be similar to that of solid pancreatic endocrine neoplasms (PENs). This study aims to describe the characteristics of CPENs in a large patient cohort.

STUDY DESIGN

We performed a retrospective review of 170 patients who underwent resections for PENs at Massachusetts General Hospital from 1977 to 2006. Twenty-nine patients (51% men, mean age 53) with CPENs were compared with 141 patients with solid PENs. Differences in clinical presentation, pathologic and radiographic features, and survival were described.

RESULTS

CPENs comprised 17% of all PENs (29 of 170) and 5.4% of all resected cystic pancreatic neoplasms(29 of 535). Ten (34%) were purely cystic and 19 (66%) were partially cystic. Compared with solid PENs, CPENs were larger (49 mm versus 23.5 mm, p < 0.05), more likely symptomatic (73% versus 45%, p < 0.05), and more likely nonfunctional (80% versus 50%, p < 0.05). They expressed synaptophysin (100%), chromogranin (82%), and cytokeratin (CK)-19 (24%). Multiple endocrine neoplasia type 1 (MEN-1) was 3.5 times more common in CPENs than in solid tumors (21% versus 6%, p < 0.05). No significant difference was found in location, propensity for metastasis, invasion, or 5-year survival (87% versus 77%, p=0.38).

CONCLUSIONS

This series, the largest report of CPENs in the literature, shows that CPENs are more common than previously thought, so they should be included in the differential of the cystic lesions of the pancreas. CPENs are larger and more likely to be symptomatic then solid PENs. They are also more likely to be associated with MEN-1 and to be nonfunctional, suggesting they may be a distinct tumor type.

Sporadically occurring functional pancreatic endocrine tumors: review of recent literature

PURPOSE OF REVIEW

Pancreatic neuroendocrine tumors are rare neoplasms often associated with a clinical syndrome. Their rarity makes a comprehensive study difficult at any single institution, while their uniqueness makes them desirable for investigation. This review summarizes recent information and advancements concerning pancreatic neuroendocrine tumor diagnosis, imaging characteristics, treatment algorithms, and staging.

RECENT FINDINGS

Insulinomas and gastrinomas comprise the majority of functional pancreatic neuroendocrine tumors. Advances in their identification and diagnostic evaluation, imaging techniques, and treatment algorithms are presented. Furthermore, a new staging classification system has been proposed which may significantly improve the ability to conduct future multi-institutional investigations on pancreatic neuroendocrine tumors.

SUMMARY

Although rare, a thorough understanding of pancreatic neuroendocrine tumors is essential for all physicians due to the wide variety of symptoms with which patients present. Currently, patients are often misdiagnosed for extended periods of time. This review summarizes the recently published literature about diagnosis, imaging, treatment, and staging of pancreatic neuroendocrine tumors.