A case of pancreatic solid-pseudopapillary neoplasm with marked ossification

Abstract

A cystic lesion of the pancreas was detected in a 25-year-old asymptomatic woman during a company medical checkup. Abdominal computed tomography (CT) revealed an ossified lesion in the pancreatic body, and the patient was referred to us for further management. Abdominal ultrasound and endoscopic ultrasound showed a hypoechoic mass with a large ossific focus, measuring 25 mm in the pancreatic body. CT and magnetic resonance imaging (MRI) showed a nonenhancing tumor lesion with a large calcific focus, measuring 20 mm in the pancreatic body. Endoscopic retrograde pancreatography revealed mild stenosis of the main pancreatic duct near the ossific focus in the pancreatic body. From the above, a pancreatic solid-pseudopapillary neoplasm (SPN) was suspected, and resection of the pancreatic body was performed. Intraoperatively, a whitish tumor measuring about 20 mm was recognized. Histopathologically, moderately large-sized tumor cells containing eosinophilic cytoplasm were arranged in a pseudopapillary formation, and infiltrated the surrounding normal tissue with ossification. Immunostaining was positive for α1-antitrypsin, not inconsistent with the diagnosis of SPN. We report this case of pancreatic SPN with ossification and a review of the literature.

Bone morphogenetic protein‐2 expression in an intraductal papillary mucinous neoplasm with marked ossification: A case report

“…Several local factors are known to promote the metaplasia of fibroblasts into bone tissues, including BMPs and other transforming growth factor β proteins, as well as fibroblast growth factor . BMP‐2 can induce osteoblastic differentiation from pluripotent cells, and its expression in tumor cells with ossification or calcification has been reported in several tumors . Additionally, tumors with ossification showed BMP‐2 expression while those without ossification showed low or negative BMP‐2 expression in renal cell carcinoma, rectal adenocarcinoma, and thyroid papillary carcinoma .…”

“…2,12 BMP-2 can induce osteoblastic differentiation from pluripotent cells, 3 and its expression in tumor cells with ossification or calcification has been reported in several tumors. [1][2][3][4][5][6][7][8][9]11,15 Additionally, tumors with ossification showed BMP-2 expression while those without ossification showed low or negative BMP-2 expression in renal cell carcinoma, rectal adenocarcinoma, and thyroid papillary carcinoma. 2,4,8 Our case of IPMN with ossification also showed BMP-2 expression, while the IPMNs without ossification, which we analyzed as controls, showed negative or weak BMP-2 expression.…”

“…The mechanism underlying intratumoral ossification is not well understood; however, it may involve bone morphogenetic proteins (BMPs), which are members of the transforming growth factor‐β superfamily . BMP‐2 has been shown to induce osteoblastic differentiation from pluripotent cells, and its expression has been reported in several types of tumors with intratumoral ossification . BMP‐2 is therefore considered a possible mediator of this process.…”

“…Intratumoral ossification in epithelial tumors is a relatively rare phenomenon, although it has been reported in tumors with various histological types such as renal cell carcinoma, colorectal adenocarcinoma, lung carcinoids, lung adenocarcinoma, bladder carcinoma, papillary thyroid carcinoma, pancreatic invasive ductal adenocarcinoma, solid pseudopapillary neoplasms, and intraductal tubulopapillary neoplasms (ITPNs). [1][2][3][4][5][6][7][8][9][10][11][12][13] The mechanism underlying intratumoral ossification is not well understood; however, it may involve bone morphogenetic proteins (BMPs), which are members of the transforming growth factor-β superfamily. 7,14 BMP-2 has been shown to induce osteoblastic differentiation from pluripotent cells, 3 and its expression has been reported in several types of tumors with intratumoral ossification.…”

“…7,14 BMP-2 has been shown to induce osteoblastic differentiation from pluripotent cells, 3 and its expression has been reported in several types of tumors with intratumoral ossification. [1][2][3][4][5][6][7][8][9]11 BMP-2 is therefore considered a possible mediator of this process. In this report, we present a rare case of a pancreatic intraductal papillary mucinous neoplasm (IPMN) with marked ossification, unique pathological features, and positive immunohistochemical staining for BMP-2.…”