Adult pancreatoblastoma: clinical features and Imaging findings

Abstract

The objective of this study was to illustrate the clinical, CT, MRI, and 18 F-FDG PET/CT features of adult pancreatoblastoma, an extremely rare disease. In this study, the clinical and imaging features of seven adult patients with pathologically confirmed pancreatoblastoma were retrospectively analyzed. The following parameters were evaluated: size, location, shape, margination, solid-cystic ratio, CT attenuation values or signal intensity and contrast enhancement pattern. We also analyzed whether abnormal FDG uptake occurred during 18 F-FDG PET/CT imaging. All seven patients were male (mean age 45 years; range 22-65 years). Six tumors were irregular in shape, exogenous, and grew outward from the pancreatic parenchyma, similar to branches growing from a tree trunk (85.7%). The tumor margins were clear in five patients (71.4%), and three tumors (42.9%) were encapsulated. Six tumors (71.4%) were solid, with homogeneous enhancement observed on contrast-enhanced CT and MRI. Dynamic-enhanced CT and MRI showed progressive enhancement for all tumors. On 18 F-FDG PET/CT, one tumor exhibited abnormal FDG uptake, and two tumors exhibited no abnormal uptake (66.7%). In conclusion, adult pancreatoblastoma most commonly occurs in male patients, and it usually appears as an exophytic, irregular, and hypovascular mass with well-defined margins and progressive enhancement on CT and MRI. This type of tumor always grows out of the parenchyma of the pancreas, similar to branches growing outward from a tree trunk. Abbreviations PB Pancreatoblastoma ROI Region of interest TAC Time-density curve SUVmax Maximum standardized uptake value SPN Solid pseudopapillary neoplasm ACC Acinar cell carcinoma Pancreatoblastoma (PB) is a very rare malignant epithelial neoplasm of the pancreas with multiple lines of differentiation. The annual incidence of PB is approximately 0.004 per 100,000 people, and it afflicts individuals of all ages 1. The vast majority of PB has been detected in children, with a median age of 5 years at presentation 2. This tumor type is more common in Asians, and two-thirds of the tumors in the medical literature have presented in patients of Asian descent 3-5. More rarely, PB can occur in adults, and the prognosis is worse for adults than for children 5-9. Therefore, it has been suggested that this tumor type shows biological differences between these two age groups 9. Currently, fewer than 50 adult PB cases have been reported in the literature 10 , and the information on these patients is mainly limited to clinical and pathological characteristics. To the best of our knowledge, a comprehensive analysis of their radiological features has not yet been reported. In this article, we present the cases of seven adult patients with pathology-proven PB who were examined at our institution and characterize the imaging appearance of these extremely rare tumors.

RETRACTED ARTICLE: CT, MRI, and 18F-FDG PET/CT imaging features of seven cases of adult pancreatoblastoma

“…Pancreatic duct dilatation was found in our study, with tumour tissue in the pancreatic duct observed on microscopic examination, which indicates that pancreatic duct dilation caused by adult PB is common. Mild enhancement was observed in enhanced scans in a previous report [ 9 ]. Mild enhancement in the AP was observed in two tumours in our study, showing a slow-in and slow-out pattern, similar to previous reports.…”

“…The strengthened enhancement is related to the pathology finding of a vascular structure around the squamoid corpuscles, which is a new finding that will be helpful for diagnosing adult PB. In the MRI sequence, isointensity was found on T1WI, while hyperintensity was found on T2WI in two cases, with limited diffusion [ 9 ]. Contrast-enhanced scans were consistent with CT scans, with significant enhancement in the AP [ 1 , 16 ].…”

Multimodality imaging differentiation of pancreatic neuroendocrine tumors and solid pseudopapillary tumors with a nomogram model: A large single-center study

“…Clinical information, including age, sex, clinical symptoms, tumor location, and tumor size, was collected from electronic medical records and pathological results (10.6084/m9.figshare.20073167). Multimodality imaging, including contrast-enhanced CT, MRI, EUS, and nuclear medicine imaging, was performed as previously described, and data were recollected through electronic medical systems (7,(9)(10)(11). Two experienced radiologists independently evaluated the variables of CT/MRI on a PACS workstation (GE Centricity PACS V 3.0, GE Healthcare, Milwaukee, WI, United States).…”

Adult pancreatoblastoma: Current concepts in pathology

“…The aetiology is unknown. Although most tumours are sporadic[ 11 - 15 ], few adult pancreatoblastomas have been described in the setting of familial adenomatous polyposis (FAP)[ 8 , 9 ]. Rare cases in children have been associated with Beckwith-Wiedemann syndrome[ 16 , 17 ].…”

“…Most patients are symptomatic, with very few cases discovered incidentally during routine examination and imaging[ 4 , 10 , 11 ]. There are no symptoms unique to pancreatoblastomas.…”