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Pancreatoblastoma is a rare tumor of neuroendocrine origin affecting paediatric age group. It is an extremely rare neoplasm of adults. Patients with pancreatoblastoma present with complaints of abdominal pain and distension. Clinically diagnosis is usually of a retroperitoneal sarcoma or tumor of colon. This tumor is generally detected accidentally during laparotomy and diagnosis is confirmed by histopathology. The presence of squamoid corpuscles with a morular appearance and acinar differentiation is the most characteristic feature of this tumor. In this article we present one such rare case of pancreatoblastoma in a 50yr old lady.

A blastoma is a type of cancer, which is common in children; it is caused by malignancies derived from in the precursor cells, often called blasts. Examples are nephroblastomas, retinoblastomas, pleuropulmonary blastomas, and pancreatoblastomas. Pancreatoblastomas are extremely rarely in adults. It is difficult preoperatively to distinguish this tumor from other pancreatic tumors including solid and papillary epithelial neoplasm of the pancreas (SPEN), acinar cell carcinoma, islet cell tumor, and ductal adenocarcinoma with cystic degeneration. To our knowledge, this case may be the second report of a pancreatoblastoma occurring in an adult in Korea. We report a case of a pancreatoblastoma that was confirmed by pathology, despite the radiologic finding that assumed it was a SPEN. Korean J Pancreatobiliary 2014;19(2):105-110

Pancreatoblastoma is an extremely rare tumor in children, especially under 3 months of age. This tumor may arise from any portion of the pancreas, but in more rare cases the ectopic pancreas is the origin. We are reporting a 3-month-old boy who was presented with an abdominal mass. Computed tomography images revealed a huge lobulated mass anterior to the kidneys, with internal calcification and enhancement after intravenous contrast media injection. He underwent a complete surgical resection of the mass that was located in the transverse mesocolon without any connection with the pancreas. Pathologic studies specified that the disease was pancreatoblastoma. His parents refused any chemotherapeutic regimen but continued postsurgical follow-ups.

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) biopsy, techniques of EUS-FNA, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy treatment and management. All documents are based on the expertise of the authors, a review of the literature, discussion of the draft document at several national and international meetings over an 18 month period and synthesis of online comments of the draft document on the Papanicolaou Society of Cytopathology web site [www.papsociety.org]. This document selectively presents the results of these discussions and focuses on a proposed standardized terminology scheme for pancreatobiliary specimens that correlate cytological diagnosis with biological behavior and increasingly conservative patient management of surveillance only. The proposed terminology scheme recommends a six-tiered system: Non-diagnostic, negative, atypical, neoplastic [benign or other], suspicious and positive. Unique to this scheme is the "neoplastic" category separated into "benign" (serous cystadenoma) or "other" (premalignant mucinous cysts, neuroendocrine tumors and solid-pseudopapillary neoplasms (SPNs)). The positive or malignant category is reserved for high-grade, aggressive malignancies including ductal adenocarcinoma, acinar cell carcinoma, poorly differentiated neuroendocrine carcinomas, pancreatoblastoma, lymphoma and metastases. Interpretation categories do not have to be used. Some pathology laboratory information systems require an interpretation category, which places the cytological diagnosis into a general category. This proposed scheme provides terminology that standardizes the category of the various diseases of the pancreas, some of which are difficult to diagnose specifically by cytology. In addition, this terminology scheme attempts to provide maximum flexibility for patient management, which has become increasingly conservative for some neoplasms.

Pancreatic carcinomas with acinar differentiation, including acinar cell carcinoma, pancreatoblastoma, and carcinomas with mixed differentiation, are distinct pancreatic neoplasms with poor prognosis. Although recent whole exome sequencing analyses have defined the somatic mutations that characterize the other major neoplasms of the pancreas, the molecular alterations underlying pancreatic carcinomas with acinar differentiation remain largely unknown. In the current study, we sequenced the exomes of 23 surgically resected pancreatic carcinomas with acinar differentiation. These analyses revealed a relatively large number of genetic alterations at both the individual base pair and chromosomal levels. There was an average of 119 somatic mutations per carcinoma. When three outliers were excluded, there was an average of 64 somatic mutations per tumor (range 12–189). The mean fractional allelic loss (FAL) was 0.27 (range 0–0.89) and heterogeneity at the chromosome level was confirmed in selected cases using fluorescent in situ hybridization (FISH). No gene was mutated in >30% of the cancers. Genes altered in other neoplasms of the pancreas were occasionally targeted in carcinomas with acinar differentiation; SMAD4 was mutated in six tumors (26%), TP53 in three (13%), GNAS in two (9%), RNF43 in one (4%) and MEN1 in one tumor (4%). Somatic mutations were identified in genes in which constitutional alterations are associated with familial pancreatic ductal adenocarcinoma, such as ATM, BRCA2, and PALB2 (one tumor each), as well as in genes altered in extra-pancreatic neoplasms, such as JAK1 in four tumors (17%) BRAF in three (13%), RB1 in three (13%), APC in two (9%), PTEN in two (9%), ARID1A in two (9%), MLL3 in two (9%), and BAP1 in one (4%). Perhaps most importantly, we found that more than a third of these carcinomas have potentially targetable genetic alterations including mutations in BRCA2, PALB2, ATM, BAP1, BRAF and JAK1.

Pancreatic lesions in young patients are relatively rare and, to our knowledge, the clinical value of pancreatic fine needle aspiration (FNA) in patients

Advances in the surgical management of pancreatic exocrine tumors in children Introduction: Pancreatic tumors in childhood are rare and diverse. Among them, pancreatoblastoma is the most common pancreatic tumor in young children, followed by the solid pseudopapillary tumor (SPT), which is an uncommon neoplasm characterized by low potential for malignancy that mainly occurs in young women. Complete surgical resection is the treatment of choice. Following the advances in minimally invasive surgery, laparoscopic distal pancreatectomy appears to be feasible and safe in children. Objective: To report a case of a child with SPT to create awareness on this topic and update its surgical management. Case report: The case of a 10 year old boy carrying a pancreatic tumor, who sought medical attention due to abdominal pain after minor trauma, is reported. Ultrasonography and CT scan of the abdomen showed an 8 cm tumor in the body and tail of the pancreas, no metastases. The alpha-fetoprotein was normal. Laparoscopic corporocaudal pan-createctomy and splenectomy were performed, and the patient was discharged on the sixth postoperative day without incident. Biopsy confirmed SPT. Discussion: This study exposes the characteristics and classification of pancreatic tumors in childhood. In particular, SPT is discussed regarding diagnosis and the advantages of minimally invasive surgery as part of the treatment.(Key words: Tumor, pancreas, pancreatectomy, laparoscopic, children).Rev Chil Pediatr 2013; 84 (4): 417-424RESUMENIntroduccion: Los tumores pancreaticos en la infancia son infrecuentes y diversos. Dentro de ellos, el pan-creatoblastoma es el mas frecuente en ninos pequenos, seguido por el tumor solido pseudopapilar (TSP), que es una neoplasia de bajo grado de malignidad que predomina en ninas y mujeres jovenes. La reseccion quirurgica completa, es su tratamiento de eleccion. En la medida del progreso de la cirugia minimamente in-vasiva , la pancreatectomia laparoscopica parece ser factible y segura en ninos. Objetivo: Comunicar el caso clinico de un nino con TSP para alertar sobre esta patologia y actualizar acerca de su manejo quirurgico. Caso

Pancreatoblastoma is a rare pancreatic tumor that is most commonly encountered in infants and young children. This report describes an unusual presentation of a large pancreatic body pancreatoblastoma presenting with intraabdominal bleeding due to spontaneous rupture of the tumor in a 5-year-old boy. Subsequent molecular analysis from the resected specimen identified a mutation in CTNNB1 and aberrant methylation of the tumor suppressor RASSF1A.

BACKGROUND Acinar cell neoplasms of the pancreas are rare but when encountered, the diagnosis is often established based on cytology specimens. Diagnostic accuracy is important because acinar cell carcinomas are aggressive yet may mimic tumors with different outcomes and management. METHODS The authors identified all patients with a diagnosis of acinar cell neoplasm in the institutional database; assessed cytomorphology and immunocytochemistry for trypsin, chymotrypsin, synaptophysin, chromogranin A, and MIB-1; and compared all cytology and final histological diagnoses for diagnostic discrepancies. RESULTS Cytological features were described for 16 histologically proven malignant acinar cell neoplasms: acinar cell carcinoma (8 cases), mixed acinar-neuroendocrine carcinoma (6 cases), mixed acinar-ductal carcinoma (1 case), and pancreatoblastoma (1 case).The majority of aspirates from acinar cell cystadenomas were nondiagnostic or negative (5 of 6 cases; 83%). Acinar and neuroendocrine differentiation that was detected by immunocytochemistry in >20% of tumor cells was found to be correlated with mixed acinar-neuroendocrine carcinoma histology. Cytohistological correlation included 32 patients with 17 discordant diagnoses (53%). The following preoperative cytology diagnoses proved to be acinar cell neoplasms on resection: neuroendocrine tumor (5 cases), adenocarcinoma (5 cases), atypical ductal cells (2 cases), solid pseudopapillary neoplasm, and hepatocellular carcinoma. Three aspirates diagnosed as acinar cell carcinoma by cytology proved to be chronic pancreatitis (2 cases) and ductal adenocarcinoma (1 case). CONCLUSIONS Acinar cell carcinoma has a distinctive cytological appearance but is frequently misdiagnosed on cytology. Immunocytochemistry is useful for identifying acinar differentiation. Cancer (Cancer Cytopathol) 2013;121:459–70. © 2013 American Cancer Society.

Pancreatoblastoma is a rare pediatric pancreatic malignancy. It confers a worse prognosis if there is metastatic or unresectable disease. We report a case of a 12-year-old boy who presented with pancreatoblastoma of the head of the pancreas with multiple intrahepatic metastases. We successfully treated him using aggressive chemotherapy, multi-stage surgery, and gemcitabine chemotherapy, which has not been described as treatment for pancreatoblastoma. Rare childhood malignancies such as pancreatoblastoma require a coordinated, multidisciplinary approach and frequent reassessment of therapeutic interventions. Complete surgical resection is important for cure and may require complex, aggressive, multiple-stage surgical procedures with concurrent or novel chemotherapy.

Most cases of pancreatoblastoma, a rare malignant epithelial tumor of the pancreas, are seen in the pediatric population. The rarity of pancreatoblastoma, the similar radiologic findings to those seen in other pancreatic lesions, and its histopathologic heterogeneity, make its preoperative diagnosis in adults a real challenge. We report ultrasound, computed tomography and magnetic resonance imaging correlative findings of a histologically proven pancreatoblastoma in a 37-year-old woman. Pancreatoblastoma should be considered in the differential diagnosis of a pancreatic mass presenting uncommon imaging features. info:eu-repo/semantics/publishedVersion

Pancreatic neoplasms are uncommon in children. This study sought to analyze the clinical and pathological features of surgically resected pancreatic tumors in children and discuss management strategies. We conducted a retrospective review of patients ≤21 years with pancreatic neoplasms who underwent surgery at a single institution between 1995 and 2015. Nineteen patients were identified with a median age at operation of 16.6 years (IQR 13.5–18.9). The most common histology was solid pseudopapillary neoplasm (SPN) (n = 13), followed by pancreatic neuroendocrine tumor (n = 3), serous cystadenoma (n = 2) and pancreatoblastoma (n = 1). Operative procedures included formal pancreatectomy (n = 17), enucleation (n = 1) and central pancreatectomy (n = 1). SPNs were noninvasive in all but one case with perineural, vascular and lymph node involvement. Seventeen patients (89.5 %) are currently alive and disease free at a median follow-up of 5.7 (IQR 3.7–10.9) years. Two patients died: one with metastatic insulinoma and another with SPN who developed peritoneal carcinomatosis secondary to a concurrent rectal adenocarcinoma. Pediatric pancreatic tumors are a heterogeneous group of neoplastic lesions for which surgery can be curative. SPN is the most common histology, is characterized by low malignant potential and in selected cases can be safely and effectively treated with a tissue-sparing resection and minimally invasive approach.

Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare neoplasm that accounts for 2-3% of all primary pancreatic neoplasms. This study aimed to characterize clinicopathological features associated with SPNs and to retrospectively evaluate the relationship of these features with predictive parameters associated with aggressive behavior. We reviewed 16 cases of SPN of the pancreas that had been diagnosed between 2005 and 2014 at our pathology department. A total of 16 cases, 15 female and one male, were evaluated in this study. The patient age ranged from 13 years to 63 years with a median of 35.70 years. The mean tumor diameter ranged from 2 cm to 18 cm with a mean diameter of 5.90 cm. We identified a significant association between the presence of clear cells and perineural invasion (p = 0.019), which was considered to be a predictive factor for aggressive behavior. Other features (i.e., localization, nuclear grooves, central hyalinization, myxoid stroma, eosinophilic bodies, foamy histiocyte aggregates, multinucleated cells, and calcification) were not significantly associated with predictive factors for aggressive behavior. One patient died as a result of a pancreatic fistula that developed as a postoperative complication. The remaining 15 patients are alive and have not demonstrated any signs of recurrence or metastasis. The current study suggested that the presence of clear cells might serve as a possible prognostic indicator of perineural invasion, which is a predictive parameter associated with aggressive behavior in SPN. Copyright

Pancreatoblastoma, is rare exocrine malignant tumour of childhood. We are reporting a case of three-year-old child presented to our hospital suffering from vague abdominal pain for further examination and treatment. Clinical examination revealed only a palpable abdominal mass. CT Scan revealed a huge complex space occupying lesion 9.1x8.8x9.2cm with large central cystic degeneration and lobulated enhancing peripheral solid components with foci of calcification, seem to arise from body and tail regions of pancreas. Surgery was done and mass was removed. By histopathology and immunohistochemistry it was diagnosed as pancreatoblastoma. The prognosis is very good in paediatric age, lacking evidence of metastatic disease at first presentation. Therefore early diagnosis is needed for specific treatment. The case is being reported because of its rarity.

This review describes the clinicopathologic characteristics, differential diagnosis, and biologic behavior of exocrine pancreatic tumors of predominantly nonductal differentiation: acinar cell carcinoma, pancreatoblastoma, and solid-pseudopapillary neoplasm. Patients usually present with a well-demarcated, large, soft, solitary mass with expansile, rather than infiltrative, growth pattern. Cystic change is common. Histologically, the tumors usually reveal at least a focal solid, cellular appearance composed of uniform, monomorphic epithelial cells. However, each type has characteristic clinicopathological features. The immunohistochemical labeling profile of pancreatoblastoma parallels the multiple lines of differentiation. These tumors are capable of producing metastases; however, their behavior is different among the types and even in the same type. Therefore, establishment of a grading system that can predict the outcome would be helpful.

BACKGROUND: Histologic characteristics have proven to be very useful for classifying different types of tumors of the pancreas. As a result, the major tumor types in the pancreas have long been classified based on their microscopic appearance. MAIN BODY: Recent advances in whole exome sequencing, gene expression profiling, and knowledge of tumorigenic pathways have deepened our understanding of the underlying biology of pancreatic neoplasia. These advances have not only confirmed the traditional histologic classification system, but also opened new doors to early diagnosis and targeted treatment. CONCLUSION: This review discusses the histopathology, genetic and epigenetic alterations and potential treatment targets of the five major malignant pancreatic tumors - pancreatic ductal adenocarcinoma, pancreatic neuroendocrine tumor, solid-pseudopapillary neoplasm, acinar cell carcinoma and pancreatoblastoma.

Primary neoplastic change can occur in all of the histological components of the pancreas. The term “pancreatic cancer” is commonly used to describe pancreatic ductal adenocarcinoma and its associated variants, which arise from the ductal cells and account for 85–90 % of all pancreatic neoplasms. However, neoplasms can also arise from other components of the gland, including stem cells, neuroendocrine cells, lymphoid and stromal cells. Rarely, metastases to the gland also occur. It is important to recognize and understand these tumors as their natural history can differ significantly from pancreatic adenocarcinomas.

Background: Most studies have failed to identify any prognostic value of the current T-stage protocol for pancreatic ductal adenocarcinoma (PDAC) by the American Joint Committee on Cancer and the Union for International Cancer Control unless some grouping was performed. Methods: To document the parameters included in this T-stage protocol, 223 consecutive pancreatoduodenectomy specimens with PDAC were processed by a uniform grossing protocol. Results: Peripancreatic soft tissue (PST) involvement, the main pT3 parameter, was found to be inapplicable and irreproducible due to lack of a true capsule in the pancreas and variability in the amount and distribution of adipose tissue. Furthermore, 91 % of the cases showed carcinoma in the adipose tissue, presumably representing the PST, and thus were classified as pT3. An additional 4.5 % were qualified as pT3 due to extension into adjacent sites. The T-stage defined as such was not found to have any correlation with survival (p = 0.4). A revised T-stage protocol was devised that defined pT1 as 2 cm or smaller, pT2 as >2–4 cm, and pT3 as larger than 4 cm. This revised protocol was tested in 757 consecutive PDACs. The median and 3-year survival rates of this size-based protocol were 26, 18, 13 months, and 40 %, 26 %, 20 %, respectively (p

This chapter explores the pathologic features of benign and malignant lesions of the pancreas. As pathologic classifications evolve, particularly for cystic lesions and neuroendocrine tumors, it is important for physicians who treat patients with pancreatic neoplasms to fully evaluate these pathologic classifications.

Pancreatic neoplasms in children are very uncommon, representing less than 1 % of all solid tumors. Because of their rarity, our understanding of their natural history is limited. Pancreatic neoplasms are divided into epithelial and non-epithelial categories. Epithelial tumors are those with a cell line that resembles the lining of the pancreatic ducts, the lining of the pancreatic acini or the cells that form the islets of Langerhans, which can be functional or clinically silent. Non-epithelial tumors are those that arise from tissue of mesenchymal or ectodermal origin, which are extremely rare. In general, pancreatic neoplasms in children have an overall better prognosis than in adults, although some tumors in children are very aggressive, unresectable at diagnosis and have a poor survival rate. Among all different types of pancreatic neoplasms in children, pancreatoblastoma (PBT) and solid-pseudopapillary tumor (SPPT) are the most common ones in the first and second decade of life, respectively. Complete surgical resection is the key in the treatment of all pancreatic neoplasms in children.

The case of a six-month-old child with pancreatoblastoma is presented. Pancreatoblastoma is a rare primary neoplasm of childhood, usually presenting in children ranging from 2 −8 years old. The radiologic findings vary from solid to complex masses. This case is unusual due to the young age of the patient.

A recent review of the literature identified more than 150 reported cases of pancreatoblastoma in children. However, the clinical, histological and therapeutic characteristics of this tumour are hardly known by most paediatric surgeons and oncologists. The clinical symptomatology is often discrete, such as abdominal pain and/or intestinal transit disturbances, and the revealing sign is usually the discovery of a voluminous abdominal mass. Pancreatoblastoma is most often located in the head or body of the pancreas but can be seen in any part of the pancreas. It forms a full mass, rather well encapsulated, round and soft in consistency, often large in size and that can develop beyond the limits of the pancreatic gland. The metastases may be present in the lymph nodes, liver, lungs and spleen. It is an embryonic organ tumour that morphologically resembles what the nephroblastoma or the hepatoblastoma are for the kidneys or liver, respectively. The pathological analysis characteristically shows two components in which cell density is often high: an epithelial component and a mesenchymatic component. The lab test evaluation should include an assay of alpha-foetoprotein. Elevated levels of this marker are often present in these tumours. An assay of this marker is therefore interesting, not only at the time of diagnosis, but especially for early diagnosis of relapses. The pancreatoblastoma treatment is above all surgical and only complete exeresis makes recovery possible. However, at the time of diagnosis, many patients are inoperable due to the extension of the tumour. The combination of cisplatin + adriamycin seems to be the most effective neoadjuvant chemotherapy regimen. Patients who have had an incomplete tumour exeresis pose a real problem due to the frequency of local relapses and/or metastases. Local irradiation is indicated in this case, as chemotherapy has not yet provided proven results in this context.

Pancreatoblastoma is a rare pancreatic tumor. In this study, 3 cases of childhood pancreatoblastoma that arise from the tail of the pancreas were reported. Abdominal pain and vomiting were observed in 1 case considering the huge size of the tumor. The other 2 patients, who were previously well, complained of a mass in the abdomen after a casual physical examination. Elevated serum α-fetoprotein levels were noted in all cases. Imaging findings indicated a well-defined heterogeneous large mass in the left retroperitoneal space. Exploratory laparotomy revealed a large mass, arising from the tail of the pancreas. Surgery alone with complete excision of the masses was performed. Immunohistochemical staining showed that only α-fetoprotein was positive in all cases. All of these 3 cases have a good outcome in the follow-up without adjuvant chemotherapy. These data suggest that the diagnosis of pancreatoblastoma is difficult and should be suspected at palpation of an abdominal mass. α-Fetoprotein may serve as a tumor marker for preoperative diagnosis and postoperative recurrence. Pancreatoblastoma arising from the tail of the pancreas is a curable tumor, and adjuvant chemotherapy may not be necessary if the tumor can be excised completely.

Embryonal cancers are a heterogeneous group of rare cancers which mainly occur in children and adolescents. The aim of the present study was to estimate the burden (incidence, prevalence, survival and proportion of cured) for the principal embryonal cancers in Europe (EU27), using population-based data from cancer registries (CRs) participating in RARECARE. We identified 3322 cases diagnosed from 1995 to 2002 (latest period for which data are available): 44% neuroblastoma, 35% nephroblastoma, 13% retinoblastoma and 6% hepatoblastoma. Very few cases of pulmonary blastoma (43 cases) and pancreatoblastoma (seven cases) were diagnosed. About 2000 new embryonal cancers were estimated every year in EU27, for an annual incidence rate of 4 per million (1.8 neuroblastoma, 1.4 nephroblastoma, and 0.5 retinoblastoma); 91% of cases occurred in patients under 15 years. Five-year relative survival for all embryonal cancers was 80% (99% retinoblastoma, 90% nephroblastoma, 71% hepatoblastoma and 68% neuroblastoma). Overall survival was lower in adolescents and adults than in those under 15 years. The cure rate was estimated at 80%. Slightly less than 40,000 persons were estimated alive in EU27 with a diagnosis of embryonal cancer in 2008. Nephroblastoma was the most prevalent (18,150 cases in EU27), followed by neuroblastoma (12,100), retinoblastoma (5200), hepatoblastoma (2700) and pulmonary blastoma (614). This is the first study to delineate the embryonal cancer burden in Europe by age, sex and European region. Survival/cure rate is generally high, but there are considerable gaps in our understanding of the natural histories of these rare diseases particularly in adults.

Pancreatoblastoma is an extremely rare pancreatic tumour most commonly encountered in infants and young children. This is a case of childhood pancreatoblastoma being reported to emphasize the dilemma of clinical and radiological features in diagnosing this rare tumour. A 3-year-old boy complained of distension of the abdomen with mild jaundice. Initially, physical and radiological investigations were in favour of liver abscess. Histopathological examination of the resected specimen was interpreted as liver mass. Serological investigations and immunohistochemistry for malignancy were helpful in suspecting Pancreatoblastoma. Pancreatoblastoma can mimic a liver mass (caudate lobe) on imaging as is shown in this case report. DOI: http://dx.doi.org/10.3126/njr.v1i1.6321 Nepalese Journal of Radiology Vol.1(1): 33-36

Pancreatoblastoma is a rare malignant tumor of the pancreas mostly diagnosed in childhood. The clinical presentation and outcome of infantile and congenital pancreatoblastoma have not been clearly elucidated. This report describes our recent institutional experience with an unusual case of congenital pancreatoblastoma. Review of the scientific literature identifies approximately 200 cases of pancreatoblastoma. We describe the 9 infantile (aged 3 mo and younger) and 4 congenital cases previously reported and summarize their clinical presentation and outcome. We also define the close association of infantile/congenital pancreatoblastoma and Beckwith-Wiedemann syndrome (50%) versus all affected age groups (4.5%).

In this report, we describe a classic case of stroma rich neuroblastoma, nodular type in a 22 year old female presented with a pancreatic mass. This rare and unusual presentation elicits several differential diagnostic categories including solid pseudopapillary tumor, pancreatic endocrine tumor, pancreatoblastoma and PNET. In this report, we tried to differentiate between them depending on the histopathological features and using panel of epithelial and neuroendocrine markers. Although of the rarity of pancreatic neuroblastoma as a primary site of origin, however it should be considered in the differential diagnosis of pancreatic masses in children and young adult. Neuropil and ganglionic differentiation are helpful features to recognize neuroblastoma and differentiate them from other small blue cell tumors. The fatal outcome of adult neuroblastoma confirming the independence of age as a prognostic factor in this neoplasm regardless of stage and histology.

Solid lesions of the pancreas represent a heterogeneous group of entities that can be broadly classified as either neoplastic or nonneoplastic. Neoplastic lesions include pancreatic adenocarcinoma, pancreatic neuroendocrine tumor, solid pseudopapillary tumor, pancreatoblastoma, pancreatic lymphoma, metastases to the pancreas, and rare miscellaneous neoplasms. Nonneoplastic lesions include focal pancreatitis, fatty infiltration-replacement, intrapancreatic accessory spleen, congenital anomalies such as prominent pancreatic lobulation and bifid pancreatic tail (pancreatic bifidum), and rare miscellaneous lesions (eg, pancreatic sarcoidosis, Castleman disease of the pancreas). A variety of imaging modalities are available for assessing these solid lesions, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging, endoscopic US, and hybrid nuclear imaging techniques such as single photon emission computed tomography-CT and positron emission tomography-CT, each of which has its own strengths and limitations. Accurate diagnosis can be challenging, and use of a multimodality imaging approach is often helpful in equivocal or complex cases. Knowledge of relevant clinical information and key radiologic features is essential for confident lesion characterization and differentiation.

Solid-pseudopapillary neoplasm of the pancreas is a rare tumor of uncertain histogenesis that is characterized by a cystic and solid growth pattern with pseudopapillary structures. The differentiation of solid-pseudopapillary neoplasm from other pancreatic tumors is of great importance. However, it is sometimes difficult because of similarities in morphologic features and immunophenotype. CD99 is a diagnostically useful marker for Ewing sarcoma/primitive neuroectodermal tumor. The aim of this study was to investigate the diagnostic value of CD99 in solid-pseudopapillary neoplasm. We investigated immunohistochemical staining for CD99 in tissue microarray blocks from 55 cases of pancreatic solid-pseudopapillary neoplasm, 51 cases of pancreatic neuroendocrine tumor, and 54 cases of pancreatic adenocarcinoma. Biopsy specimens from 7 solid-pseudopapillary neoplasms, 6 acinar cell carcinomas, and 1 pancreatoblastoma were also investigated. All the solid-pseudopapillary neoplasm cells exhibited paranuclear dot-like immunoreactivity for CD99 regardless of the clinicopathologic or morphologic features. Forty of the 51 pancreatic neuroendocrine tumors were positive for CD99. Staining here was membranous, or membranous and cytoplasmic. Four of the 54 pancreatic adenocarcinomas and 1 pancreatoblastoma showed faint membranous staining. None of the acinar cell carcinomas was reactive for CD99. Our study has identified for the first time that pancreatic solid-pseudopapillary neoplasm exhibits a unique dot-like staining pattern for CD99. This could prove to be the most useful aspect of its immunoprofile for the definitive diagnosis of solid-pseudopapillary neoplasm and differentiation from other pancreatic tumors.

Focal nodular hyperplasia (FNH) of the liver is a rare benign lesion that may be related to the vascular and hepatic damage induced by completion of tumor therapy and a reaction to localized vascular abnormality. The aim of this study was to analyze the clinical course in pediatric solid tumor patients with FNH. We analyzed thirty-two patients with pediatric solid tumors who received multiagent chemotherapy (15 advanced neuroblastomas, 7 hepatoblastomas, 5 rhabdomyosarcomas, 2 nephroblastomas, 1 rhabdoid tumor of the kidney, 1 clear cell sarcoma of the kidney and 1 pancreatoblastoma). All of them had been previously treated at our hospital, and have been alive for over 3 years without recurrence. FNH lesions were discovered in three (9.4%) of 32 patients, and were neuroblastoma (NB) stage 4. All 3 patients received induction chemotherapy and high-dose alkylating agents, and developed grade 3 (National Cancer Institute Common Toxicity Criteria; NCI-CTC) liver dysfunction during completion of tumor therapy without veno-occlusive disease. Two of the 3 patients received the same induction chemotherapy and high doses of alkylating agents with total body irradiation for cytoreductive agents prior to peripheral blood cell transplantation. FNH lesions in both female patients who received estrogen replacement therapy after completion of tumor therapy have expanded and are increasing. FNH appears to be a late complication of iatrogenic disease in NB stage 4 patients. The therapeutic agents for NB stage 4 and estrogen replacement therapy should be considered as risk factors for the development of FNH.

症例は16歳，男性．食欲不振，体重減少（1年で約5kg）を主訴として当院を受診し，腹部エコーおよび腹部CT検査にて巨大な膵頭部の腫瘍を指摘された．画像診断では膵頭部から外側方に突出するように径約7.3cmの腫瘍が認められ，十二指腸下行脚および総胆管を圧迫していた．また腫瘍内に嚢胞性変化があり腫瘍内出血が示唆された．主膵管の拡張は認められなかった．以上の所見および患者の年齢，血清AFP値が高値であることなどから膵芽腫が疑われた．入院後14日目に膵頭十二指腸切除術を施行した．術後の病理組織学的検査では，腫瘍は被膜を有し，小型の円形な核を持つ腫瘍細胞が充実性あるいは小腺管を形成して増殖しており出血壊死を伴っていた．扁平上皮小体が認められ，膵芽腫と診断された．免疫組織学的検索でAFP，α -1 antitrypsin，chromogranin Aが陽性であった．術後8年5か月を経過し，再発の兆候なく経過観察を継続中である．

Pancreatoblastoma (PB) is a rare malignant pancreatic tumor in children and approximately 200 cases have been reported in the literature. The overall 5-year survival rate in PB is 43–50% and no standard treatment for PB has been established. This report presents the case of a 6-year-old female with advanced PB treated successfully by a pylorus-preserving pancreatoduodenectomy (PPPD) after induction chemotherapy, radiation and stem cell transplantation (SCT). A 6-year-old girl was hospitalized for abdominal pain, fever, and vomiting. Abdominal computed tomography (CT) scan showed a 9-cm heterogeneous mass located at the pancreatic head and body, and the duodenum was completely compressed. The inferior vena cava, superior mesenteric artery, and vein were encased by the tumor. The tumor had well-defined margins and calcification. She showed severe anemia and her hemoglobin level was 4.0 g/dl, and the serum alpha-fetoprotein (AFP) level was elevated (884.8 ng/ml). Initially, a resection of the tumor was impossible. An open biopsy was performed and the histopathological diagnosis was PB. She underwent five cycles of the induction chemotherapy regimen for advanced neuroblastoma (cyclophosphamide, etoposide, vincristine, pirarubicin and cisplatin), and the tumor size was decreased to a diameter of 7.5 cm. Furthermore, chemotherapy with irinotecan and vincristine, radiotherapy (40 Gy) and SCT (etoposide, carboplatin, melphalan) was administered. The serum AFP level decreased to 41.1 ng/ml, and the tumor size was decreased to a diameter of 6.5 cm. Then she underwent a PPPD and the tumor was completely resected. The patient’s recovery was uneventful, and the AFP returned to the normal values (6.2 ng/ml) after surgery. The child was administered mild postoperative chemotherapy using irinotecan and has been disease-free for 4 months and, and her serum AFP levels remain within normal values. This is the first case of PB that was treated with SCT effectively before surgery. The combined therapy including the intensive chemotherapy with SCT and the radiation followed by surgical treatment is thought to be effective for the treatment of advanced PB.

Pancreatoblastoma (PB) is a rare malignant neoplasm of the pancreas, which occurs mostly during childhood. Presently, the optimal treatment strategy is neither clear nor uniform for patients in advanced stages, in particular those with metastasis, inoperable, or recurrent tumors. To our knowledge, until now, only one patient with PB has been treated with hematopoietic stem cell transplantation (HSCT) following aggressive chemotherapy and surgical resection. Here we report the second case of PB who was treated with aggressive chemotherapy combined with autologous peripheral blood stem cell transplantation.

Pancreatoblastoma is a rare malignant tumor in children. Surgical resection of the tumor is necessary for cure; however, due to its aggressive nature, it is often unresectable at presentation due to tumor size, local invasion, and/or metastasis. Because it is a rare tumor, there is currently no standard treatment regimen. We report a case of a 4-year-old boy who presented with metastatic pancreatoblastoma with multiple large metastases involving all four sectors of the liver. We began treatment with chemotherapy (cisplatin, 5FU, vincristine, and doxorubicin), which significantly reduced the tumor burden in both the pancreas and liver. We then performed a staged subtotal pancreatectomy, complete hepatectomy, and living donor left lateral segment liver transplant. This was followed by postoperative adjuvant chemotherapy. Our patient is alive and healthy and has now been tumor-free for 7 years with no tumor relapse.

As the most common and most important cancer of the pancreas, with rapid mortality and now also as the third leading cause of cancer-related deaths in the United States, pancreatic ductal adenocarcinoma (PDAC) has become synonymous with "pancreas cancer". PDAC is also the prototype of the "pancreatobiliary-type" adenocarcinomas, along the biliary tract, ampullary and gallbladder cancers with the similar morphology and behavior. Recent molecular profiling studies have identified distinct subsets of PDAC, potentially with different behaviors and targetability. Moreover, while PDAC is by far the most common cancer of the pancreas, there are various other types that occur in this organ and are erroneously classified together with PDAC. Many of these have different molecular and biologic characteristics that warrant their management separately although they are also technically "pancreatic cancers". While some are closely related to PDAC and have as aggressive behavior (such as adenosquamous carcinomas which are recently recognized under "basal" like category in profiling studies, which are actually even worse prognostically than PDACs), in the meantime, others such as colloid carcinoma has a much better behavior than PDAC, and as a carcinoma with intestinal lineage (MUC2/CDX2) colloid carcinoma may require an entirely different treatment approach as well. Similarly, medullary carcinomas also appear to have different biology. Additionally, non-ductal cancers such as acinar, neuroendocrine, solid-pseudopapillary neoplasms and pancreatoblastoma have their respective clinicopathologic and molecular associations and warrant careful elimination in the management and study protocols. Another very problematic aspect in the classification of "pancreas cancer" is its delineation from the cancers of neighboring organs, in particular, ampullary/duodenal and common bile duct (CBD) cancers, for which recently more refined criteria have been provided. Additionally, the possibility of metastasis from another site and lymphomas also need to be considered. In summary, there is a whole host of cancers that occur in the pancreas that ought to be considered carefully before a case is classified as an ordinary "pancreas cancer" (PDAC).

Introduction Malignant pancreatic tumors are exceedingly rare in pediatric age and their clinical features and treatment usually go unappreciated by most pediatric oncologists and surgeons. Methods From January 2000 to July 2009, 21 patients

Given advances in diagnostic imaging and surgical technique, a variety of neoplastic and non-neoplastic pancreatic lesions are increasingly encountered in clinical practice. The distinction of these lesions has significant therapeutic and prognostic implications. Herein, we review the major clinicoepidemiologic and pathologic features of ductal adenocarcinoma, pancreatic cystic neoplasia, pancreatic endocrine tumor, and related lesions. Emphasis is placed on frozen-section diagnosis and differential diagnostic features. Also, potential diagnostic pitfalls are highlighted, such that they may be avoided. After reading this article, readers should be able to discuss ductal adenocarcinoma, in particular histologic features useful in frozen section evaluation and in its distinction from chronic pancreatitis; recognize distinguishing features of neoplastic and non-neoplastic pancreatic cysts, particularly those useful in the separation of the mucin-producing cystic neoplasms; and describe the clinical, histologic, and immunophenotypic features of the cellular epithelioid tumors including pancreatic endocrine tumor, solid pseudopapillary tumor, acinar cell carcinoma, and pancreatoblastoma.

Rare malignant pediatric tumors are essentially orphan diseasesand make up a variety of neoplasms with particular biological andclinicalcharacteristics.Someofthesetumorsarerareatanyage,butmost are particularly rare in childhood and adolescence [1].In 2000, a nationwide Italian cooperative project, called theTREP (Tumori Rari in Eta` Pediatrica or Rare Tumours in PediatricAge) project, was launched in Italy under the auspices of theAssociazione Italiana Ematologia Oncologia Pediatrica (AIEOP),and in cooperation with the Societa` Italiana Chirurgia Pediatrica(SICP) to improve basic research on these tumors and their clinicalmanagement. The project aimed to establish a network of pediatricand adult oncologists, surgeons, pathologists and biologists, to poolclinical data, and develop diagnostic and therapeutic recommenda-tions for each of these rare tumors [2].As a first step, the TREP group gave an arbitrary but pragmaticdefinition of ‘‘rare pediatric tumors,’’ defining them as solidmalignancies characterized by annual incidence rates of less than2 per million children (0–14 years) and not enrolled in specificclinical trials. The list included: nasopharyngeal carcinoma,adrenocortical tumors, pleuro-pulmonary blastoma (and other lungtumors), carcinoid tumors, cutaneous melanoma, renal carcinoma,pancreatoblastoma (and other pancreatic exocrine tumors), gonadalnon-germ-cell tumors (ovary/testis), pheochromocytoma and para-ganglioma, thyroid carcinoma, salivary gland tumors, breastcarcinoma, carcinoma of the gastrointestinal tract, and carcinomaof the thymus [2]. Therefore, the list excluded entities as renalrhabdoid tumors, that are registered in the national Wilms study;hepatoblastomaandmalignantgermcelltumors,thathavetheirownprotocols; rare histotypes of soft part sarcomas, that are covered bythe cooperative study on soft tissue sarcomas, as well as rare bonetumors; and other tumors whose incidence parallels that of rarepediatric tumors butwere already included in clinical trials. Centralnervous system tumors and hematological malignancies wereexcluded from the TREP list.TheTREPgrouphasalreadypublishedareportonitsfirst6yearsof activity. Here, we compare the number of these rare pediatrictumors expected to be diagnosed in Italy (based on incidence datafrom Italian network of well-established population-based cancerregistries [AIRTum]) [3] and the number of patients enrolled in theTREP project between 2000 and 2006, with a view to appraisingthe nationwide diffusion and efficacy of the TREP project. Thestudy analyzed the differences in the patterns of referral of children(0–14 years old) and adolescents less than 18 years (15–17 yearsold) with rare malignant tumors.