Case ReportPrimitive Neuroectodermal Tumor of the Pancreas:A Case Report and Review of the Literature
Uir Teixeira, Marcos Goldoni, Michelle Unterleider, Joo Diedrich,Diogo Balbinot, Pablo Rodrigues, Rodolfo Monteiro, Daniel Gomes,Jos Sampaio, Paulo Fontes, and Fbio Waechter
Gastrointestinal and Hepato-Pancreato-Biliary Surgical Division, Federal University of Health Sciences ofPorto Alegre/Santa Casa Hospital of Porto Alegre, 91410-000 Porto Alegre, RS, Brazil
Correspondence should be addressed to Uira Teixeira; email@example.com
Received 16 February 2015; Revised 9 May 2015; Accepted 14 May 2015
Academic Editor: Steve de Castro
Copyright 2015 Uira Teixeira et al. This is an open access article distributed under the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Primitive neuroectodermal tumors (PNETs) are presented as rare malignant neoplasms. In unusual cases, those neoplasms mayarise in solid organs containing neuroendocrine cells, such as the pancreas. Herein the case of a 28-year-old patient that underwentgastroduodenopancreatectomy after the diagnosis of a hugemass (PNET) located in both head and body of the pancreas is reported.This is the 19th case of pancreatic PNET reported in literature.
Primitive neuroectodermal tumors (PNETs) are presentedas rare malignant neoplasms, showing different degrees ofdifferentiation. They are often classified as small round celltumors arising from soft tissues. PNETs also integrate Ewingssarcoma family of tumors (ES), which represents 1% of allsarcomas [1, 2].
In rare cases, PNETs may arise in solid organs containingneuroendocrine cells, with previous reports on kidneys, uri-nary bladder, ovaries, uterus, parotid glands, heart, and lungs. Besides these organs, the pancreas can also develop thistype of tumors which accounts for 0.3% of the primarypancreatic neoplasms [4, 5]. Except for the case discussedhere, only 18 other occurrences of pancreatic PNETs werepreviously reported in the worlds literature.
These neoplasms occur predominantly in pediatric andteenaged populations , in a rate of 6.5 per million inpatients up to 14 years .They also present an insidious onsetand often asymptomatic or poorly symptomatic course, evenin advanced stages [4, 5].
A proper integration of the pathological, clinical, immun-ohistochemical, and cytogenetic findings is necessary for
a successful diagnosis of pancreatic PNETs and also fordistinguishing this group from other neoplasms with similarpresentations . Despite its rarity, this type of neoplasmmust be considered in differential diagnosis when searchingfor pancreatic masses, especially in patients under 35 years ofage .
In spite of the poor prognosis, surgical treatment followedby chemotherapy or radiotherapy or both is the most widelyaccepted option, given the aggressiveness of such neoplasms.This is the case report of a 28-year-old patient that under-went surgery after PNET diagnosis, located in both head andbody of the pancreas.
2. Case Report
A 28-year-old female patient was admitted to the EmergencyDepartment of Santa Casa Hospital in Porto Alegre, Brazil.Shewas referring epigastric pain for 14 days, with partial reliefdue to the use of weak analgesics. The pain was associatedwith diffuse cutaneous pruritus, jaundice, choluria, andacholia.
On physical examination, the patient was in a good gen-eral condition, jaundiced, with a hardened palpable mass in
Hindawi Publishing CorporationCase Reports in SurgeryVolume 2015, Article ID 276869, 4 pageshttp://dx.doi.org/10.1155/2015/276869
2 Case Reports in Surgery
Table 1: Laboratorial findings.
Total bilirubin 4mg/dLDirect bilirubin 3,1mg/dLAlkaline phosphatase 319U/LGamma-glutamyl transpeptidase 136U/LGlutamic-oxaloacetic transaminase 371U/LGlutamic-pyruvic transaminase 759U/LCA19-9 2,9U/mLCEA 3,0 ng/mL
Figure 1: Abdominal ultrasonography showing a huge heteroge-neous mass.
the epigastric and right hypochondrium regions. Laboratorytests showed a cholestatic pattern (Table 1). Tumoral markers(CEA and CA19-9) were normal.
Initially, an abdominal ultrasonography was performed,revealing a voluminous heterogeneous hypoechoic massmeasuring about 13 cm width, 9 cm length, and 13 cm height.It presented cystic areas inside, between left hepatic lobeand pancreas. It was not possible to determine the origin ofthe mass. Dilatation of intrahepatic bile ducts and proximalcommon bile duct was also referred to (Figure 1).
Computerized tomography with intravenous contrastunfolds a voluminous expansive lesion in pancreatic head andbody, withwell delimited borders,measuring about 12.8 12.1 10.9 cm. A heterogeneous density due to the presence ofboth liquid and solid areas is also shown in the CT.The imageshowed intense enhancement of an intravenous contrastagent. The lesion displaced adjacent structures, althoughno infiltration was detected. A significant ectasia of theintrahepatic and extrahepatic bile ducts could also be seen(Figure 2).
The patient was evaluated by the hepatopancreatobiliaryteam and underwent a gastroduodenopancreatectomy, per-formed uneventfully. The gross appearance of the lesion wasa solid cystic mass, was encapsulated andmultiloculated, andwas with necrotic aspect areas, measuring a total of 11.5 cmalong its longest axis (Figure 3).
The pathological study revealed a neoplasm of smallround blue cells with scant cytoplasm arranged in nestswith fibrovascular stroma. Few mitosis pictures and severalareas of necrosis were also found. Immunohistochemistry
Figure 2: Abdominal CT reveals a voluminous lesion in pancreatichead and body (arrow).
Figure 3: Surgical specimen.
was strongly positive for CD99 (Figure 4), vimentin, auto-mated CKM (creatine kinase, muscle), and CD56. Further-more, it was negative for antibodies present in neuroen-docrine tumors (chromogranins, synaptophysin, and neu-roblastoma), myogenin, automated CD10, -catenin, auto-mated RP (ribosomal protein), and LCA (leucocyte commonantigen).
The patient recovered well postoperatively, presentingnormalized levels of bilirubin, alkaline phosphatase, -glutamyl transpeptidase, aspartate aminotransferase, and ala-nine aminotransferase. She was discharged on the 13th dayafter surgery and remains well, without signs of recurrenceafter 3 years. Considering R0 resection and controversies inthe literature, adjuvant treatment with chemotherapy and/orradiotherapy was not performed.
Primitive neuroectodermal tumors (PNETs) represent about1% of all sarcomas and have a five-year survival rate ofapproximately 50% [13, 7]. There are rare cases in whichPNETs develop in solid organs [3, 8] arising, mainly, insoft tissues of the toracopulmonar region, pelvis, and lowerlimbs of children and young adults . In organs containingneuroendocrine cells as the pancreas such kind of tumoris especially rare, accounting for 0.3% of primary tumors.[3, 4, 9, 10].
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Figure 4: Small round cells with scant cytoplasm; immunohistochemistry was positive for CD99.
Histologically, the ES family of tumors is made of smallmonomorphic round cells with small nuclei and scant cyto-plasm; nonetheless, there is a large group of tumors withthe same pattern [2, 11]. What determines the familiaritybetween PNETs and ESs is the presentation, in both, ofthe same cytogenetic change. This change is seen in mostof their malignant cells and consists of the characteristicchromosomal translocation t(11; 22) (q24; 12) [2, 3, 5, 1113]. More than 90% of the ES/PNET shows this specific andreproducible translocation that evolves with variable degreesof differentiation.This is a reason formany authors to suggestthat ES/PNET family is, actually, the same tumoral cell indifferent ends of the spectrum of differentiation [2, 6, 11, 12,14].
An association of pathological, immunohistochemical,clinical, and cytogenetic features is, therefore, required fordiagnosing pancreatic PNETs . Furthermore, pancreaticPNETs must be included in the differential diagnosis oftumors containing small undifferentiated or poorly differen-tiated cells, neuroendocrine carcinomas, and pancreatoblas-tomas, among others [3, 6, 10].
Immunohistochemistry is extremely useful in diagnos-ing this neoplasm, as peripheral primitive neuroectodermaltumors substantially express a cell surface glycoprotein. Thisglycoprotein is product of theMIC2 gene (a pseudoautosomalgene located on the short arm of the X and Y chromosomes ofPNETs and ESs cells), also called CD99 or p30/32MIC2, whichis considered important in cell adhesion [2, 3, 6, 15].
Regarding the clinical presentation, it can be said thatthere is no specific set of symptoms for pancreatic PNETs.The onset of the disease seems to be insidious and producingfew symptoms, with abdominal pain during palpation of themass being the most referred to symptom. Mao et al. indicate that patients tend to present jaundice, occurringmainly as obstructive jaundice; high gastrointestinal bleedingand severe anemia are also possible. Additionally, a uniquecase of hyperglycemia was reported by Mao et al.
Bose et al.  pointed out that, among 16 patientsreported with ES/pancreatic PNET, 10 referred to abdominalpain as the most common symptom, with or without othersymptoms.Moreover, jaundicewas present in the diagnosis of5 cases; 2 children (both females) were affected by precocious
puberty, as well as 2 other cases with iron deficiency anemiasecondary to gastrointestinal bleeding.
Among imaging tests, abdominal CT and MRI are themost used in the detection of these tumors. The di