Pancreatoblastoma: an unusual diagnosis in an adult patient. Clin J Gastroenterol. 2018;11:161-166. [PMID: 29285688 DOI: 10.1007/s12328-017-0812-6]

Robotic Distal Pancreatectomy for Adult Pancreatoblastoma with Tumor Extension to the Main Pancreatic Duct: A Case Report

INTRODUCTION

Adult pancreatoblastoma (PB) is an extremely rare malignant pancreatic epithelial tumor. Although no standard treatment strategy has been established, complete resection is recommended for long-term survival. Here, we presented a case of an adult patient with PB who successfully underwent complete resection via robotic surgery. Furthermore, this is the first report of robotic surgery for PB, highlighting its novelty and potential clinical relevance.

CASE PRESENTATION

A 40-year-old man presented with epigastric pain, and image examination revealed a well-defined tumor in the pancreatic tail extending into the main pancreatic duct (MPD) and reaching the pancreatic neck. With no evidence of distant metastases, surgery was planned following 2 courses of gemcitabine and S-1 chemotherapy for tumor shrinkage. There were no significant changes in the tumor's extension after chemotherapy, but no new lesions appeared, and robotic distal pancreatectomy was performed. Intraoperative findings confirmed the tumor extension into the MPD just above the superior mesenteric vein (SMV). The pancreas was sharply divided at the right edge of the SMV, and a negative transection margin was obtained. The pancreatic stump was closed by suture. The postoperative course was uneventful, and the pathological diagnosis confirmed PB with MPD and inferior mesenteric vein invasion.

CONCLUSIONS

We successfully resected an adult case of PB with tumor extension into the MPD via robotic surgery. Robotic surgery enabled precise pancreatic transection at the right edge of the SMV, ensuring a negative pancreatic transection margin in this case. In addition, robotic surgery contributed to the safe and secure suture closure of the pancreatic stump.

Adult Pancreatoblastoma: Clinical Insights and Outcomes Compared to Pancreatic Ductal Adenocarcinoma (PDAC)

Pancreatoblastoma is perceived to be aggressive in adults; however, data are limited due to the rarity of the disease. We benchmarked clinico-pathologic characteristics, outcomes, and survival of adult patients with pancreatoblastoma to a comparable PDAC cohort using the National Cancer Database (NCDB). This study included 301,204 patients: 35 with pancreatoblastoma and 301,169 PDAC patients. Pancreatoblastoma patients were younger than PDAC patients (56 vs. 69 years, p < 0.001). More pancreatoblastoma patients were managed at academic institutions (63.0% vs. 40.7%, p = 0.047). The most frequent primary site was the head and the neck of the pancreas. There were no differences in tumor size (4.2 cm vs. 3.7 cm, p = 0.828), lymph node positivity (14.3% vs. 26.4%, p = 0.103), or metastasis at time of diagnosis (31.4% vs. 46.1%, p = 0.081). The majority of pancreatoblastoma patients underwent resection compared to a minority of PDAC patients (69.7% vs. 15.5%, p < 0.001). Time from diagnosis to surgery was longer for pancreatoblastoma patients (33 vs. 14 days, p = 0.030). Pancreaticoduodenectomy was the most common type of resection in the pancreatoblastoma and PDAC groups (47.8% vs. 67.7%, p = 0.124). Among resected patients, pancreatoblastoma patients were less likely to receive radiation (4.8% vs. 37.0%, p = 0.002), but the use of chemotherapy was similar to PDAC patients (60.9% vs. 70.7%). After matching, median overall survival was longer for pancreatoblastoma than PDAC (59.8 months vs. 15.2 months, p = 0.014).

Blastomas of the digestive system in adults: A review

Blastomas, characterized by a mixture of mesenchymal, epithelial, and undifferentiated blastematous components, are rare malignant neoplasms originating from precursor blast cells. This review focuses on digestive system blastomas in adult patients, including gastroblastoma, hepatoblastoma, and pancreatoblastoma. Gastroblastoma is a biphasic, epitheliomesenchymal tumor, with only sixteen cases reported to date. In addition to the characteristic histology, metastasis-associated lung adenocarcinoma transcript 1 - glioma-associated oncogene homolog 1 gene fusion is typical, although recently novel ewing sarcoma breakpoint region 1 - c-terminal binding protein 1 and patched 1 - glioma-associated oncogene homolog 2 fusions have been described. Hepatoblastoma is exceptionally rare in adults and can show a variety of histologic patterns which may cause diagnostic difficulty. Pancreatoblastoma, primarily a pediatric tumor, displays acinar differentiation and squamoid nests with other lines of differentiation also present, especially neuroendocrine. Diagnostic approaches for these blastomas include a combination of imaging modalities, histopathological examination, and molecular profiling. The treatment generally involves surgical resection, which may be supplemented by chemotherapy or radiotherapy in some cases. Prognoses vary with gastroblastoma generally showing favorable outcomes post-surgery whereas hepatoblastoma and pancreatoblastoma often have poorer outcomes, particularly in the setting of metastases. This review highlights the complexity of diagnosing and managing these rare adult blastomas as well as the need for ongoing research to better understand their pathogenesis and improve treatment strategies.

A Subset of Pancreatoblastomas May Arise From an Adenomatous Precursor: An Ampullary Pancreatoblastoma and Adjacent Adenoma With a Shared Molecular Phenotype in an Adult Patient

ABSTRACT

Pancreatoblastomas are rare pediatric tumors. In adults, they are exceedingly rare and seem to have a worse prognosis. Most are sporadic, though rare, cases occur in patients with familial adenomatous polyposis. Unlike pancreatic ductal adenocarcinomas, pancreatoblastomas are not believed to arise from dysplastic precursor lesions. Clinical history, along with endoscopic, pathological, and molecular findings, was reviewed for a 57-year-old male patient with an ampullary mass who presented with obstructive jaundice. Microscopic examination showed a pancreatoblastoma subjacent to an adenomatous polyp with intestinal differentiation and low-grade dysplasia. Both tumors had abnormal p53 (complete loss) and nuclear β-catenin immunostaining. Mutational panel analysis showed an identical CTNNB1 (p.S45P) mutation in both. This case adds to our understanding of the pathogenesis of these rare tumors and suggests that a subset may arise from an adenomatous precursor. In addition, this case is just the second pancreatoblastoma to originate in the duodenal ampulla, and the preceding case suggests that an ampullary location leads to earlier diagnosis. Moreover, this case highlights the difficulty in diagnosing pancreatoblastoma on limited tissue specimens and illustrates the need to include pancreatoblastoma in the differential diagnosis in all tumors in and around the pancreas, including those in adult patients.

Adult pancreatoblastoma: Current concepts in pathology

Adult pancreatoblastoma is an exceptionally rare malignant tumour of the pancreas that mimics other solid cellular neoplasms of the pancreas, which may pose diagnostic difficulties. Because of its rarity, little is known about its clinical and pathologic features. This article reviews the clinical and pathologic features of pancreatoblastoma in adults including differential diagnosis, treatment, and follow-up. Although pancreatoblastoma commonly occurs in childhood, there have now been more than 70 adult pancreatoblastomas described in the literature. There is a slight male predominance. There are no symptoms unique to pancreatoblastomas and adult patients are frequently symptomatic. The most common presenting symptom is abdominal pain. Grossly, the tumours are often large and well-circumscribed. Microscopically, pancreatoblastomas are composed of neoplastic cells with predominantly acinar differentiation and characteristic squamoid nests. These tumours are positive for trypsin, chymotrypsin, lipase, and BCL10. Loss of heterozygosity on chromosome 11p is the most common molecular alteration in pancreatoblastomas. Adult pancreatoblastomas are aggressive tumours with frequent local invasion, recurrence, and distant metastasis. Treatment consists of surgical resection. Chemotherapy and radiotherapy may have a role in the treatment of recurrent, residual, unresectable, and metastatic disease. It is important to distinguish pancreatoblastomas from morphological mimics such as acinar cell carcinomas, solid pseudopapillary neoplasms, and pancreatic neuroendocrine neoplasms.

Adult pancreatoblastoma: clinical features and Imaging findings

The objective of this study was to illustrate the clinical, CT, MRI, and ¹⁸F-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 ¹⁸F-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 ¹⁸F-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.

Metastatic adult pancreatoblastoma: Multimodal treatment and molecular characterization of a very rare disease

BACKGROUND

Pancreatoblastoma is a rare malignancy that occurs predominantly in children. Less than 50 adult cases, including 17 patients with metastatic disease, have been published to date. Recent outcome data from children with advanced-stage disease suggest an intensive multimodal treatment approach; however, little is known about the most beneficial therapy in adults. Molecular characterization of pancreatoblastoma is limited to a small number of pediatric cases and revealed few recurrent genetic events without immediate clinical relevance.

METHODS

Patients were treated between 2013 and 2018 at a high-volume German university cancer center. Molecular analyses included whole genome, exome, transcriptome, and fusion gene panel sequencing. Molecularly guided treatment recommendations were discussed within a dedicated molecular tumor board (MTB) embedded in a precision oncology program (NCT MASTER).

RESULTS

We identified four adult patients with metastatic pancreatoblastoma. In three patients, local approaches were combined with systemic treatment. Oxaliplatin-containing protocols showed an acceptable tumor control as well as an adequate toxicity profile. Overall survival was 15, 17, 18 and 24 months, respectively. Three tumors harbored genetic alterations involving the FGFR pathway that included an oncogenic FGFR2 fusion.

CONCLUSION

Oxaliplatin-containing chemotherapy seems to be a reasonable approach in adult patients with advanced pancreatoblastoma, whereas the benefit of intensified treatment including local ablative techniques or surgical resection remains unclear. Our finding of FGFR alterations in three of four cases indicates a potential role of FGFR signaling in adult pancreatoblastoma whose clinical significance warrants further study.

Adult Pancreatoblastoma With Liver Metastasis Diagnosed by 18F-FDG PET/CT and 2 Years' Postoperative Follow-up

Pancreatoblastoma is an extremely rare malignant tumor of the pancreas. Most patients are infants and children; however, a few cases have been reported in adults. Herein, we present the case of a 49-year-old man with pancreatoblastoma and liver metastasis who underwent preoperative multimodal imaging, in which F-FDG PET/CT showed a markedly increased F-FDG uptake in the metastatic lesion and a slightly increased uptake in the primary lesion. Subsequently, the patient underwent complete resection of the primary and metastatic lesions. No recurrences or metastases were found in 2 years of follow-up.

Pancreatoblastoma: Cytologic and histologic analysis of 12 adult cases reveals helpful criteria in their diagnosis and distinction from common mimics

BACKGROUND

Pancreatoblastoma (PBL) is a rare malignant pancreatic tumor seen predominantly in childhood, and its cytologic diagnosis remains challenging.

METHODS

Twelve fine-needle-aspirations from 11 adults were analyzed.

RESULTS

In total, 6 men and 5 women (median age, 45 years; age range, 32-60 years) had tumors measuring a median 5.6 cm (range, 2.5-12 cm) located in the pancreatic head (n = 7) or tail (n = 4), including 3 with familial adenomatous polyposis (FAP)/FAP-related syndromes and 4 with metastasis at diagnosis. The median follow-up was 39.8 months (range, 0.8-348 months), and 5 patients died of disease. The original cytology diagnoses were: PBL (n = 2), neuroendocrine neoplasm (n = 2), poorly differentiated neuroendocrine carcinoma (n = 2), well differentiated neuroendocrine tumor (n = 1), poorly differentiated carcinoma (n = 2), "positive for malignancy" (n = 1), acinar cell carcinoma (n = 1), and epithelioid neoplasm with endocrine and acinar differentiation versus PBL (n = 1). Universal cytopathologic findings included hypercellularity; 3-dimensional clusters; and single, monotonous, blast-like cells that were from 1.5 to 2.0 times the size of red blood cells with high nuclear-to-cytoplasmic ratio, fine chromatin, small, distinct nucleoli, and a resemblance to well differentiated neuroendocrine tumor and poorly differentiated neuroendocrine carcinoma. Branching pseudopapillae (n = 7) and grooved nuclei (n = 3) raised the differential diagnosis of solid-pseudopapillary neoplasm, but with more atypia. Uncommon features included pleomorphism (n = 4) and numerous mitoses (n = 1). Squamoid morules were seen on smears (n = 5) or cell blocks (n = 6) in 70% of patients and were characterized by epithelioid cells with elongated, streaming nuclei, fine chromatin, absent nucleoli, and positive nuclear β-catenin (n = 6 of 8). The median Ki-67 index was 21% (range, 2%-70%), and neuroendocrine marker expression was common (100%), but acinar markers were variable (63%).

CONCLUSIONS

A combination of cytologic findings in PBL, including a predominant population of primitive blast-like cells, subtle squamoid morules, frequent neuroendocrine and variable acinar phenotype, should facilitate accurate cytologic diagnosis and distinction from common mimics.

Complete Surgical Resection and Aggressive Treatment for Liver Metastasis May Be Beneficial to Adult Patients With Pancreatoblastoma: A Case Report and Review of Literature

Introduction:

Pancreatoblastoma (PB) is a rare pancreatic neoplasm that occurs most in pediatric patients. Here, we report a rare case of adult PB with liver metastasis and review the literature in order to assist clinicians in the management of the disease.

Case Presentation:

A 27-year-old female patient suffered from postprandial fullness, anorexia, and weight loss in the past 3 months. An abdominal ultrasound and contrast-enhanced computed tomography scans confirmed right abdominal mass with compression of major liver vessels, as well as the P-duct and biliary ducts and causing mild dilatation. Pancreatoduodenectomy was performed and pathologic findings showed typical squamoid corpuscles, which confirmed the diagnosis of PB. The patient was alive and disease-free for 1 year and 10 months until a new metastatic lesion was found. Radiofrequency ablation was arranged as a curative treatment, and no viable tumor or sign of recurrence was found until this paper was submitted. Based on a review of previous case reports, we found adult PB patients with only liver metastasis presented with a smaller tumor size (P = 0.031), more frequent pancreatic head origin (P = 0.043), and decreased 1-year mortality (P = 0.009) compared with patients with other distal metastases. Therefore, we assumed that PB with liver metastasis might present favorable outcome by complete surgical resection or other curative treatment.

Conclusion:

PB patients with liver metastasis are more likely to show a pancreatic head origin, smaller tumor size, and more favorable outcomes compared with other sites of metastasis. PB should be treated aggressively with surgical resection or other curative treatment as opposed to chemotherapy alone.