Pancreatic Solid and Cystic Hamartoma in Adults

Abstract

Nonneoplastic tumor-like lesions ("pseudotumors") of the pancreas include cystic and noncystic varieties. We report on a solid and cystic tumor-like lesion of the pancreas that occurred in 2 adult patients. The lesions, located in the head and neck of the gland, respectively, were well demarcated and composed of cystic ductal structures embedded in focally inflamed stromal tissue. In addition, one of the lesions showed irregularly arranged but well-differentiated acini and small intralobular and interlobular ducts embedded in hypocellular, fibrotic tissue. Discrete islets were lacking, but immunohistochemical staining for chromogranin A revealed individual scattered endocrine cells evenly distributed between acinar and ductal cells. The surrounding pancreatic parenchyma did not show significant chronic pancreatitis. After tumor removal, the follow-up of the patients was uneventful. Because of the irregular arrangement of otherwise mature tissue components of the pancreas, the lesions were considered solid and cystic hamartomas. Their pathogenesis is so far unknown.

Pancreatic hamartoma diagnosed after surgical resection

“…Recently, true hamartomas of this organ have been characterized. Pancreatic hamartoma is divided into two subgroups: solid and cystic, and solid pancreatic hamartoma [2,3]. …”

“…US shows hyperechoic solid masses with or without a cystic change [6]. On CT, the tumor is a well-circumscribed, iso- or hypoattenuated, solid and/or cystic mass, with heterogeneous contrast enhancement [2,5,8]. MRI demonstrates a relatively well-defined mass.…”

Letters to Editor Asymptomatic solid pancreatic hamartoma

“…They may appear as solid masses or cystic forms and should be regarded as malformations rather than neoplasms [1]. Due to absence of characteristic differential features they may be clinically and radiologically mistaken for a malig7-18062cy [2]. Misinterpretation of hamartoma as a true neoplasm may result in unnecessarily aggressive surgery.…”

“…Clinicopathological features of all noted cases are summarized in Table I [2-10]. Some authors have observed that this kind of lesion includes spindle-shaped cells which are immunoreactive for CD34 and CD117 [9].…”

Benign Tumors and Tumorlike Lesions of the Pancreas

“…Well-formed islets of Langerhans are not common. In fact, Pauser et al 118, 120 and Yamaguchi et al 121 defined the criteria for the diagnosis of pancreatic hamartoma as: (1) forming a well-demarcated mass, (2) being comprised of mature acini and ducts with distorted architecture, and (3) lacking discrete islets of Langerhans. Adjacent pancreatic parenchyma is usually unremarkable.…”