S1489 Solid Pseudopapillary Pancreatic Tumor: Preoperative Malignant Potential and Gender Differences

Abstract

INTRODUCTION: Solid pseudopapillary tumor (SPT) is a rare tumor that was first described by Virginia Frantz in 1959. It is found most commonly in females in the second or third decade of life, and less commonly found in males. We herein present two cases of SPT, one discovered in a young female and the other in an elderly male, followed by literature review of this interesting disorder of the pancreas with emphasis on preoperative predictors of malignancy and gender differences in presentation. CASE DESCRIPTION/METHODS: Case 1 is a 30 years old healthy female who presented with right lower abdominal pain and vomiting that persisted for days after a night of moderate alcohol consumption. Basic labs were unrevealing, and ultimately a computerized tomography (CT) of the abdomen discovered a 3.2 × 2.8 × 1.8 cm pancreatic tail mass with cystic and solid components. On endoscopic ultrasound fine needle biopsy (EUS-FNB), lesion was anechoic and hypoechoic, measuring 3.1 × 2 cm. Immunohistochemical staining was positive for CD56, CD 10, CD 117, and B-Catenin consistent with SPT. The patient was referred to surgery and ultimately underwent an uncomplicated distal pancreatectomy. The surgical pathology was consistent with SPT. Case 2 is a 64 years old male with hyperlipidemia, chronic obstructive pulmonary disease and atrial fibrillation who presented with diffuse abdominal pain, nausea and vomiting. Basic labs were unrevealing, and CT revealed a 2.3 cm mass in pancreatic head. Subsequent magnetic resonance imaging showed a cystic mass with some solid debris. EUS-FNA with biopsy showed hypoechoic mass with smooth margins measuring 2.1 × 2.1cm. Immunohistochemical staining was positive for CD 56, CD 10, vimentin, androgen receptor, cylcin D1. Ki-67 stain demonstrated low proliferative labeling index. The patient ultimately underwent a robotic Whipple surgery. Pathologic evaluation was consistent with SPT. DISCUSSION: SPT is a pancreatic neoplasm with low malignant potential. Factors that predict malignancy preoperatively have been studied. Additionally, Males and females can have different presenting features of the tumor. However, given its low incidence, proven risk factors and the extent of impact have been challenging to discover. Furthermore, some malignant features can be missed on preoperative evaluation. Therefore, a large multicenter prospective or metanalysis study might be needed to better assess and differentiate demographic and clinical risk factors that can help in determining prognosis.Figure 1.: Image A: Cystic mass lesion with rim calcification in the tail of the pancreas in female patient.Figure 2.: Image B: Hypodense lesion in pancreatic head in male patient.Figure 3.: Image C: Pancreatic head cystic mass on MRCP in male patient.