Infantile Extrapancreatic Pancreatoblastoma: A Report on a Rare Infantile Abdominal Mass Hossein Esfahani, MD,* Elham Olad, MD,w Arash Dehghan, MD,z Hassan Bazmamoun, MD,y and Manoochehr Ghorbanpoor, MDw Summary: Pancreatoblastoma is an extremely rare tumor in chil- dren, 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 chemo- therapeutic regimen but continued postsurgical follow-ups. Key Words: pancreatoblastoma, infantile, pancreatic neoplasms, ectopic (J Pediatr Hematol Oncol 2014;36:241–245) A lthough the most common malignant pancreatic tumor in children is pancreatoblastoma, pancreatic neoplasms are rare in childhood. This tumor typically affects children between 1 and 8 years of age, with a mean age of 5 years at the time of presentation. 1,2 Infantile type of the disease that occurs in infants younger than 3 months of age is extremely rare, with only 14 cases reported in the literature by now. By physical examination, it may be difficult to distinguish pancreatic tumors from other abdominal masses in child- hood, particularly when the tumor is extrapancreatic pan- creatoblastoma. Complete surgical resection is the most important prognostic factor in managing this rare tumor. 3 We are reporting an infant boy with a mesenteric-origi- nated retroperitoneal mass, which was diagnosed as pancreatoblastoma. CASE REPORT The patient was 3 months old when his parents noticed an abdominal mass. He was delivered by normal vaginal delivery to a 25-year-old first gravid mother who had an unremarkable medical history, except a doubtful x-ray exposure during the second- trimester of her pregnancy when she was located in the radiology department for less than half an hour as she was accompanying a patient. Pelvic sonography was performed during the second tri- mester of pregnancy that was reported normal. The first visit of the patient at birth, which was done by a general pediatrician, was also reported normal. Growth and development were normal. The patient was not icteric and did not have any abnormal physical findings, except a firm abdominal mass, which was palpable in his right upper quadrant. Despite the ultrasonography that speci- fied 2 calcified solid masses measuring 86 72 and 31  36 mm anterior to the right kidney and left retroperitoneum suggestive of neuroblastoma, computed tomography (CT) images revealed only a big lobulated heterogeneous solid mass in the midline and ante- rior to the kidneys. The mass had defined borders, was internally calcified, and enhanced after intravenous contrast media injection (Fig. 1). At the time of presentation in the third month of age, liver function tests and serum electrolytes were reported as normal. Urinary levels of vanillylmandelic acid, metanephrine, carcinoem- bryonic antigen, and serum levels of b-human chorionic gonado- tropin were also reported normal; however, serum levels of lactate dehydrogenase (1773 U/L) and a-fetoprotein (AFP > 1000 ng/mL) were elevated according to the reference ranges (normal reference range for 3 mo infants: 88 ± 87 ng/mL). 4 The patient underwent laparotomy and 1 huge lobulated mass measured 10 10 cm with dilated vessels adhering to the transverse mesocolon, and omentum was detected. The mass was located near the pancreas but was not seen in the pancreatic tissue. The entire mass and the affected mesocolon were resected. In a pathologic sample, grossly, the tumor was a spherical- shaped mass measuring 100  80  60 mm and weighing 250 g. The cut surface revealed a solid creamy-white tumoral tissue with foci of hemorrhage, necrosis and cystic degeneration (Fig. 2). Micro- scopically, the tumor was highly cellular and comprised variably sized lobulated tumor cells separated by thin fibrous septa. These cells were predominantly arranged in sheets of rosette-like struc- tures with lumens resembling the pancreatic acini (Figs. 3A, B). The tumor cells were uniform and had a moderate amount of fine eosinophilic granular cytoplasm. The nuclei were uniformly round or oval with stippled chromatin; mitotic activity was easily identi- fied with 1 mitotic figure per high power field. In addition, there were small whorl areas composed of large tumor cells with- abundant eosinophilic cytoplasm, consisting of squamous morules. Remnant of the pancreatic tissue was also noted in a pathologic section (Figs. 4A, B). Immunohistochemical staining revealed dif- fuse cytokeratin positivity in tumor cells, focal positive neuron- specific enolase, and negative S-100. After surgery and definite diagnosis of pancreatoblastoma, more comprehensive evaluation was performed that did not show any metastasis. The patient did not receive adjuvant chemotherapy because of lack of parental consent. On follow-up, he was visited every month for 6 months and then every 3 months in the first year. Serum AFP and lactate dehydrogenase levels were evaluated and abdominal sonography was performed every 3 months, which were reported normal during his follow-up. At present, in the second year of his follow-up, patient is in a good health status and is visited every 3 months. DISCUSSION Pancreatoblastoma originates from the exocrine epi- thelial cells of the pancreas. Other childhood exocrine Received for publication January 31, 2013; accepted June 13, 2013. From the Departments of *Pediatric Hematology/Oncology; wPedi- atrics; zPathology; and yPediatric Gastroenterology, Hamadan University of Medical Science, Hamadan, Islamic Republic of Iran. The authors declare no conflict of interest. Reprints: Hossein Esfahani, MD, Pediatric Hematology/Oncology Department, Besat Hospital, Motahari Blvd., Resalat Square, Hamadan, 6514845411, Islamic Republic of Iran (e-mail: hesfehani@ yahoo.com). Copyright r 2013 by Lippincott Williams & Wilkins CLINICAL AND LABORATORY OBSERVATIONS J Pediatr Hematol Oncol  Volume 36, Number 3, April 2014 www.jpho-online.com | 241