Figure 4: Gross appearence of the pancreatic mass after midline incision: both frankly necrotic and cystic areas were present.
The occurrence of pancreatic tumors in children is a rarity (<<0.5:10,000 surgical operations).
Pancreatoblastoma or infantile adenocarcinoma is an unusual non-functional tumor of the pancreas; it is generally encapsulated, presents organoid pattern containing globular structures with elongate cells (squamoid corpuscles) and acinar or ductal cells or both4. It contains both epithelial and mesenchymal elements20. Horie has subclassified them into two groups: ventral type, occurring in the head, and dorsal type occurring in body and tail with relatively immature histology and poor prognosis7.
This case demonstrates that it is possible to suspect pancreatic origins of a heterogeneous mass, predominantly located under the left lobe of the liver, detected by ultrasound in the 3rd trimester of pregnancy. Our case demonstrated some cystic and solid components.
The differential diagnosis of fetal pancreatic tumor includes hamartoma, hemangioendothelioma, benign teratomas (mainly dermoid cysts), and lymphosarcomas20. There is as yet no information on how to differentiate these tumors.
The differential diagnosis of fetal cystic intra-abdominal includes ovarian cysts8-10, mesenteric and enteric cysts, urachal cysts, multicystic kidneys11-13 and hydrocolpos. Ovarian cysts appear predominantly fluid and are present only in female fetuses. Renal dysplasias appear in the renal fossa on both sides of the spine. Meconium peritonitis is characterized by multiple calcifications. The prenatal diagnosis of intrabdominal neoplasm is only presumptive and is limited to a few cases which have been described in the literature referring to nephroblastoma14,15 (more solid appearing and more lateral) or sacrococcygeal teratoma of the intra-abdominal type16-19 (lower in the abdomen). The significance of the high a-fetoprotein values is uncertain.
Pancreatoblastomas have been found in neonates with Beckwith-Wiedemann syndrome20 and associated findings of this syndrome should be sought (macroglossia, visceromegaly, omphalocele, polyhydramnios,..).
The overall prognosis of pancreatoblastoma depends on the site of origin, since excision of the mass in the body and tail is more complete and less aggressive than excision in the head.
These tumors tend to have a good prognosis, accounting only for 0.2% of deaths for malignancies in this age1 , although poor results and occasional distant metastases (lung, liver or lymph nodes5,6) have been reported. Some series have also reported a high surgical mortality21, that some tumors may not be amenable to surgical resection22 and that the tumor may require chemotherapy and even recur23. Considering the favorable prognosis after excision, this tumor should be differentiated from the usual adenocarcinoma of the pancreas that afflicts adults.
Prenatal management: Since prenatal diagnosis of pancreatoblastoma has not been previously reported, we believe that no alteration of the prenatal care is suggested at this time. Polyhydramnios may occur if the neoplasm resides in the head of the pancreas and may contribute to the onset of premature labor; tocolytic agents are indicated in these patients, and amniotic fluid drainage may also be considered. Delivery is recommended in a tertiary care center, where neonates can receive adequate surgical care.
Postnatal management: Surgery offers the best treatment. The success of the operation largely depends on the site of the tumor. Excision of the mass in the tail or body is easier and less disruptive than removal in the head which requires major procedures such as pancreatoduodenostomy. Once surgery has been radical, chemo- and radiotherapy have proved to be unnecessary2, 3.
The most common presentations of pancreatoblastoma are abdominal distension and a palpable mass. If the tumor arises from the head of the pancreas, vomiting and jaundice are often present.
When suspected, diagnosis is confirmed by CT scan or MRI which shows the pancreatic origin of the mass.
1. Tsukimoto I, Watanabe K, Lin J, et al: Pancreatic carcinoma in children in Japan. Cancer 31:1203-1207, 1973.
2. Hampton Rich R, Weber JL, Shandling B: Adenocarcinoma of the pancreas in a neonate managed by pancreatoduodenectomy. J Ped Surg 21:806-808, 1986.
3. Maeda H, Matsumoto K, Ohmiya A, et al: A case of pancreatoblastoma. Pediatr Oncol 27:144-146, 1990.
4. Horie A, Yano Y, Miwa A: Morphogenesis of pancreoblastoma. Infantile carcinoma of the pancreas. Report of 2 cases. Cancer 39:247- 254, 1977.
5. Buchino JJ, Castello FM, Nagaraj HS: Pancreatoblastoma. A histochemical and ultrastructural analysis. Cancer 53: 963-969, 1984.
6. Immamura M, Yokoama S, Nishino C, et al: A case of AFP producing pancreatoblastoma. Pediatr Oncol 20:212-213, 1984.
7. Horie A: Pancreatoblastoma. Histologic criteria based upon a review of six cases. In Humphrey GB, Grindey GB, Dehner LP et al (eds): Pancreatic Tumors in Children. The Hague, The Netherlands, Martinus Nijhof pp.159-166, 1982.
8. Tabsh KM: Antenatal sonographic appearence of a fetal ovarian cyst. JCU 1:329, 1982.
9. Rizzo N, Gabrielli S, Perolo A, et al: Prenatal diagnosis and management of fetal ovarian cyst. Prenat Diagn 9:97, 1989.
10. Lindeque BG, Du Toit JP, Muller LMM, et al: Ultrasonographic criteria for the conservative management of antenatally diagnosed fetal ovarian cyst. J Reprod Med 33:196, 1988.
11. Friedberg JE, Mitnick JS, David DA: Antepartum ultrasonic detection of multicystic kidney. Radiology 131:198, 1979.
12. Greene LF, Feinzaig W, Dahlin DC: Multycistic dysplasia of the kidney with special reference to the controlateral kidney. J Urol 103:482. 1971.
13. Henderson SC, Van Kolken RJ, Rahatzad M: Multicystic kidney with hydramnios. JCU 8:249, 1980.
14. Warkany J: Wilms"tumor. In: Congenital Malformation. Chicago, Year Book, 1981, p.1061.
15. Wexler HA, Poole CA, Fojaco RM: Metastatic neonatal Wilms" tumor: a case report with review of the literature. Pediatr Radiol 3:179, 1975.
16. Gergely RZ, Edn R, Schriffin BS, et al: Antenatal diagnosis of congenital sacral teratoma. J Reprod Med 24:229, 1980.
17. Flake AW, Harrison MR, Adzick NS, et al: Fetal sacrococcygeal teratoma. J Pediatr Med 21:563, 1986.
18. Holzgreve W, Mahoney BS, Glick P, et al: Sonographic demonstration of fetal sacrococcygeal teratoma. Prenat Diagn 5:245, 1985.
19. Pringel KC, Weiner CP, Sopper RT, et al: Sacrococcygeal teratoma. Fetal Therapy 2:80, 1987.
20. Jaffe R: The Pancreas. In Wigglesworth JS, Singer DB (Eds): Textbook of Fetal and Perinatal pathology. Blackwell Scientic Publications, Cambridge, MA, 1991.
21. Jaksic T., Yaman M. Thorner P. et al. A 20-Year Review of Pediatric Tumors. J Pediatric Surg 27:1315-7, 1992.
22. Inomata Y., Nishizawa T., Takasan H. et al. Pancreatoblastoma Resected by Delayed Primary Operation After Effective Chemotherapy. J Pediatric Surg 27:1570-2, 1992.
23.Vannier JP, Flamant F., Hemet J. et al. Pancreatoblastoma: Response to Chemotherapy. Med Pediatr Oncol 19:187-91, 1991.