Solid pseudopapillary tumor of the pancreas.
Solid pseudopapillary tumor (SPT) is a rare tumor accounting for 1-2% of exocrine neoplasms involving the pancreas. This uncommon tumor is found predominately in young females between the second and fourth decades of life. It has a predilection for non-Caucasian women, most commonly African-American or Asian, but has been reported in children and men. SPT typically exhibit benign behavior but approximately 15% will demonstrate malignant features. Presenting symptoms may include abdominal pain or discomfort and gradually enlarging abdominal mass. However, patients are frequently clinically asymptomatic with normal laboratory values. The diagnosis is not uncommonly made incidentally in patients undergoing imaging of the abdomen for other reasons.
The imaging findings of solid pseudopapillary tumor are not pathognomonic but usually suggestive. Computed tomography (CT) frequently demonstrates a large, well-circumscribed, round or lobulated mass with a capsule. Magnetic resonance (MR) imaging may reveal a well-defined lesion with a fibrous capsule and hemorrhagic components. Microscopically, the histologic features of this neoplasm are quite distinctive. SPT generally has a much better prognosis than does the much more common and typical pancreatic adenocarcinoma. Surgical intervention with complete resection is usually curative.
A 31-year-old Caucasian female presented to the Emergency Department with a three-month history of back pain. The patient noted recent occurrence of left upper quadrant pain. No nausea, vomiting, diarrhea, constipation or other symptoms were present. Blood laboratory evaluation was unremarkable. Initial lumbar spine radiographs revealed a mass containing calcification within the left upper abdomen. (Figure 1) Ultrasound of the abdomen demonstrated cholelithiasis but could not further delineate the etiology of the abdominal mass. A 10.0 cm well-defined mass with calcification arising from the pancreatic tail was shown by CT evaluation. (Figure 2) Diagnosis of SPT was suggested after imaging evaluation and the patient was referred to surgery. Two weeks after the initial presentation, she underwent laparotomy with open cholecystectomy and distal pancreatectomy. The pancreatic tumor was removed en bloc with no evidence of metastatic disease at the time of resection. Histologic evaluation of the pancreatic mass revealed a 13 cm solid pseudopapillary tumor. The pancreatic surgical margin was free of tumor and no lymphatic, vascular or perineural invasion was identified.
A 19-year-old Caucasian female presented with a three-day history of left upper quadrant pain. She denied fevers, chills, nausea or vomiting. Past medical history included a chronic history of symptomatic nephrolithiasis. However, current left upper quadrant pain was noted as different from her chronic intermittent pain associated with renal stone disease. Blood laboratory evaluation was unremarkable. However, a well-defined pancreatic tail mass was found. CT of the abdomen and pelvis with IV contrast (Figure 3) and MR of the abdomen (Figure 4) revealed findings suggestive of SPT with no evidence of metastatic disease. The patient underwent distal pancreatectomy and splenectomy with histologic diagnosis of a 7 cm solid and papillary epithelial neoplasm. The pancreatic surgical margin was free of tumor.
Solid pseudopapillary tumor was first described as a "papillary tumor of the pancreas, benign or malignant" by Franz (1) in 1959. The number of reported cases of this rare neoplasm has increased since the report of Ave cases by Kloppel (2) in 1981. The World Health Organization (WHO) in 1996 defined and named this tumor as solid psuedopapillary tumor for histologic classification of the exocrine pancreas. Franz tumor, solid and papillary epithelial neoplasm (SPEN), solid and papillary tumor, solid and cystic tumor, papillary-cystic tumor, papillary cystic epithelial neoplasm, and solid and cystic acinar cell neoplasm are synonymous with SPT.
Although a rare tumor of the pancreas, the incidence of reported cases has increased. (3) Occurring in patients of any age or race, most tumors occur in females of African American or Asian descent. (4) Clinically, patients may present with a slowly enlarging abdominal mass. Vague abdominal pain or discomfort may occur and rarely obstructive symptoms if the tumor becomes large enough to displace adjacent viscera. Approximately 20% of patients are asymptomatic with the tumor found incidentally. (5) Laboratory evaluation and markers for pancreatic malignancy including CA19-9 and carcinoembryonic antigen are typically unremarkable.
CT and MR may help differentiate SPT from other pancreatic neoplasms. The classic CT feature is a large well-defined mass with varying solid and cystic components. (4) Enhancement of the solid component after contrast administration is common and calcium may be present, typically in the periphery of the mass. The pancreatic tail and head are the most common sites of involvement although the tumor may occur at any site. (6) MR may increase the specificity of the correct diagnosis by demonstrating a fibrous capsule and the presence of blood products. The complex nature of the lesion is demonstrated with a mix of high and low signal intensity on T1-and T2-weighted images. Areas of high signal on T1-weighted images and low or heterogeneous signal intensity on T2-weighted images can help identify blood products indicative of previous hemorrhage within the tumor. (3) Blood products, if present, aid in differentiating SPT from other pancreatic masses including pseudocysts, serous cystadenomas, mucin-producing neoplasms and islet cell tumors.
Gross examination of resected tumor usually reveals a large mass (mean diameter 8.0 cm) with smooth surface and well-defined margins. (7) Variable amounts of hemorrhage, necrosis and cystic change are present. The internal architecture may be predominately solid, predominately cystic, or have equal degrees of solid and cystic components. These tumors demonstrate characteristic histologic features consisting of solid and papillary cellular arrangements. A papillary configuration of epithelial cells surrounding a fibrovascular stalk is the histologic hallmark. (3) Solid areas containing necrosis, foamy macrophages, cholesterol granulomas and calcification may also be demonstrated. (8)
SPT is treated with surgery and resection is usually curative. Malignant degeneration of what is usually a benign tumor may occur in 15% of patients. (8) Metastatic disease with vascular and nerve sheath invasion manifests as disease of the liver and abdominal lymph nodes. SPT with clear criteria for metastatic disease has been designated solid and papillary carcinoma according to the WHO classification. (9) Secondary to the amenability of metastasis to resection and low-grade behavior, patients rarely succumb to this neoplasm. (10) The prognosis is excellent with Ave year survival greater than 90%, including patients with metastatic disease. (11)
The presence of a large encapsulated tumor in the tail of the pancreas in a young woman should raise suspicion of a solid pseudopapillary tumor. Imaging which adds value to the surgical planning may also reveal atypical features and metastatic disease. Because of the indolent nature and low malignant potential of these neoplasms, surgical resection for cure is the treatment in patients with or without metastatic disease. Although the imaging characteristics are variable, in the appropriate clinical situation the findings are highly suggestive. Recognition of calcification by radiograph or CT and areas of hemorrhagic degeneration as demonstrated by MR imaging in a young woman is virtually diagnostic. The correct diagnosis prior to surgical intervention may provide for the reduction in patient anxiety normally attributed to pancreatic tumor treatment and the possibility of minimizing the extent of surgical intervention.
(1.) Franz VK. Tumors of the pancreas. In: Atlas of tumor pathology: fasc 27-28, ser 7.
Washington, DC: Armed Forces Institute of Pathology, 1959: 32-33.
(2.) Kloppel G, Morohoshi T, John HD, et al. Solid and cystic acinar cell tumor of the pancreas: a tumor in young women with favourable prognosis. Virchows Arch A Pathol Anat Histol 1981; 392:171-183.
(3.) Coleman KM, Doherty MC, Bigler SA. Solid-pseudopapillary tumor of the pancreas. Radiographics 2003; 23:1664-1648.
(4.) Buetow PC, Buck JL, Pantongrag-Brown L, et al. Solid and papillary epithelial neoplasm: imaging-pathologic correlation in 56 cases. Radiology 1996; 199:707-711.
(5.) Dong DJ, Zhang SZ. Solid-pseudopapillary tumor of the pancreas: CT and MRI features of 43 cases. Hepatobiliary Pancreat Dis Int. 2006; 5:300-304.
(6.) Papavramidis T, Papavramidis S. Solid pseudopapillary tumors of the pancreas: review of the 718 patients reported in English literature. J Am Coll Surg 2005; 200(6):965-972.
(7.) Chang H, Gong Y, Xu J, et al. Clinical strategy for the management of solid pseudopapillary tumor of the pancreas: aggressive or less? Int J of Med Sci 2010; 7(5):309-313.
(8.) Lam KY, Lo CY, Fan ST. Pancreatic solid-cystic-papillary tumor: Clinicopathologic features in eight patients from Hong Kong and review of the literature. World J Surg 1999; 23:1045-1050.
(9.) Kloppel G, Solcia E, Longnecker DS, et al. World Health Organization: institutional histological classification or tumours histological typing of tumours of the exocrine pancreas 2nd ed. Berlin, Germany: Springer-Verlag, 1996.
(10.) Washington K. Solid-pseudopapillary tumor of the pancreas: challenges presented by unusual pancreatic neoplasm. Ann Surg Oncol 2002; 9(1):3-4.
(11.) Hibi T, Ojima H, Sakamoto Y. A solid pseudopapillary tumor arising from the greater omentum followed by multiple metastases with increasing malignant potential. J Gastroenterol 2006; 41:276-281.
Haley C. Schlarb, MSII
West Virginia School of Osteopathic Medicine
Alexander C. Schlarb
West Virginia University
H. Adam Ubert, MD
Department of Surgery, West Virginia University, Charleston Division
Christopher A. Schlarb, MD
Department of Radiology, West Virginia University, Charleston Division
Corresponding Author: Christopher A. Schlarb, MD, 12 Dunlevy Rd., Charleston, WV 25314. Email: email@example.com.
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|Title Annotation:||Case Series|
|Author:||Schlarb, Haley C.; Schlarb, Alexander C.; Ubert, H. Adam; Schlarb, Christopher A.|
|Publication:||West Virginia Medical Journal|
|Article Type:||Clinical report|
|Date:||Mar 1, 2015|
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