Pancreatic cystic lesion in an infant.

Pancreatic cystic lesions are rare clinical entities. To the best of our knowledge, only 38 cases have been reported in the English literature in children under the age of 2 years. We present a 2-month-old infant with a cystic lesion in the head of pancreas. We reviewed the possible causes and present our dilemmas in the management of these patients.

INTRODUCTION

Pancreatic cystic lesions are rarely seen in infants.[12] The data are scarce regarding the management of these lesions in these young patients. The prognosis of these cysts is generally good.[2] However, in some occasions, a malignant course and local recurrence has been described. Totally 38 cases in children under the age of 2 years have been reported so far. Due to this small number, the exact diagnostic workout and optimal management of the disease are not well-defined. We present a 2-month-old infant with a pancreatic cystic lesion.

CASE REPORT

A 2-month-old male infant was admitted to our hospital from a private clinic after being hospitalized for 37 days with persisting jaundice and abdominal swelling. He was born full-term (39th gestational week) with low birth weight (1770 g). On the 2nd day of his life he presented with jaundice, and on the 29th day he developed abdominal meteorism, anemia and discolorated stools.

His blood examination showed the following results: hematocrit 26.3%, aspartate aminotransferase 127 IU/L, alanine aminotransferase 120 IU/L, γ-glutaryl transferase 119 IU/L, alkaline phosphatase 325 IU/L, direct bilirubin 5.5 μmol/L, alpha-fetoprotein (AFP) 117,000 IU. An abdominal ultrasound (US) revealed a cystic lesion in the head of pancreas of 3.1 × 2.3 cm in size bilocular and a simple cyst in the right kidney (5.3 × 6.2cm). Both intra- and extra-hepatic biliary ducts appeared normal. A Doppler US scan of the portal vein similarly revealed no abnormalities. A computed tomography (CT) [Figure 1] and a magnetic resonance imaging (MRI) examination verified the results of the abdominal US.

Figure 1

Abdominal CT of a 2-month-old infant: Unenhanced scan shows a cystic mass of 3.1× 2.3cm in the head of the pancreas

An explorative laparotomy revealed a cystic mass in the pancreatic head. After aspiration of approximately 3.5 mL fluid from the cystic lesion, penrose drains were inserted for drainage of possible further postoperative fluid collections. AFP concentration in the aspirated fluid was 482 IU (normal value: <27 IU). Human chorionic gonadotropin, carcinoembryonic antigen and mucus levels were normal. The cytological examination was negative. After 12 weeks, the blood AFP levels returned to normal values. A follow-up assessment at 2, 6, 12, 24 and 36 months consisting of an abdominal US and blood examinations was unremarkable.

DISCUSSION

The first pancreatic cyst was described by Jean Cruveihlier in 1816, while the first malignant pancreatic cystic tumor was described by Luecke in 1867.[3] Cystic tumors of the pancreas are less frequent than solid lesions; they are often detected incidentally, as many of these lesions are small and asymptomatic.[4] With advancements in diagnostic imaging, pancreatic cystic lesions are being detected with increasing frequency. In adults, cystic tumors of the pancreas are relatively uncommon, accounting for 10% of pancreatic cystic lesions and 1% of pancreatic neoplasms.[4]

In the pediatric population, cystic lesions of the pancreas are rare. The true incidence of this clinical entity is not known. Furthermore, the natural history of these lesions in children and their relationship to the lesions in the adult population are not well understood.[5] Pancreatic cysts in children may be congenital–developmental, retention, duplication, parasitic pseudocysts and neoplastic. Neoplastic pancreatic cysts may be cystic teratoma, cystic lymphangioma, solid and papillary epithelial neoplasm (SPEN), cystadenoma and cystadenocarcinoma.[6]

The above classification does not apply to children under the age of 2 years, as only individual case reports are available (congenital cyst: 21 cases,[7-10] congenital pseudocyst: 5 cases,[11] cystic pancreatoblastoma Beckwith-Wiedemann: 7 cases[12] and mucinous-serous cystadenoma: 5 cases[5]).

No imaging modality is sufficiently accurate to differentiate among the multiple benign, premalignant, and malignant lesions that are visualized by US, CT, or MRI scans.[13] In the 1990s, some authorities recommended cyst aspiration with fluid analysis for cytology, amylase, viscosity and various tumor markers like CEA, CA19-9, and AFP.[14] More recently, endoscopic ultrasound (EUS) with fine-needle aspiration has been suggested as a method to differentiate among benign, premalignant, and malignant lesions.[15] However, percutaneous or endoscopic aspiration has the potential to spill malignant cells with the possibility of reducing survival.[13] Although the above described techniques may provide suggestive information for the diagnosis, the interpretation of results in individual cases may be problematic.[13]

The management of these patients is complex. Although an aggressive surgical approach has been advocated in the past, many clinicians now deem this therapeutic strategy impractical, given the rapidly increasing incidence of incidentally detected pancreatic cystic lesions.[16] Another fact that supports an initially conservative approach of these patients is the low prevalence of malignancy in cystic lesions. For example, in a retrospective study conducted by Allen et al, among 209 adult patients with pancreatic cystic lesions, only 3% were found to be malignant.[17]

In the pediatric population, the scarcity of cases limits our ability to study these tumors. Even authors from large referral centers, reporting their experience over 20–35 years, have encountered only a small number of cases.[18-20] A 20-year audit (1971–1991) in a Hospital for Sick Children in Toronto showed only six patients (age: 3 weeks–16 years) who were operated on for pancreatic neoplasms. All were treated primarily with pancreatic resection including one pancreatoduodenectomy. No radiotherapy or chemotherapy was used. The perioperative mortality was 0% with a morbidity of 50%.[19]

In another retrospective study in Riley's Children Hospital, 62 patients (28 males and 34 females; average age: 9.5 years, range: 1 week–18 years) underwent 72 pancreatic operations.[20] Although pancreatic surgery was associated with very low mortality rates in this group (1.6%), the morbidity was around 35%, which is equal to that of adult patients.[15]

According to the results of our literature survey, more than 75% of pancreatic cystic lesions in children under the age of 2 years are benign congenital cysts. The surgical approach in these cases consists of total excision for cysts located in the pancreatic body or tail, while internal procedures are reserved for lesions located in the pancreatic head.[7] To the best of our knowledge, there are no statistical data in infants regarding the outcome and the surgical risks after operative procedures in the head of pancreas.

The small size of the pancreas makes surgical maneuvers in the area quite difficult to perform. As a result, an excellent outcome cannot be guaranteed. The relatively high percentage of post-operative complications is an additional argument against applying an aggressive therapeutic modality in these patients. In addition, pancreatic surgery in children is relatively uncommon and this unfamiliarity can be associated with significant morbidity.[21] Besides this, a firm diagnosis is difficult to establish in this age group. Moreover, the long–term complications of such demanding operations are not known. It may therefore be wise to employ an initial conservative management.

CONCLUSION

The results of our literature survey suggest that the initial therapeutic approach of pancreatic cystic lesions in children below the age of 2 years may be conservative due to the high complication rates and the benign course of the disease reported in these patients. A surgical option should be reserved for those few cases with an already established diagnosis.