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

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Case report: Remarkable response to later-line surufatinib in an adult patient with liver metastatic of pancreatoblastoma

Pancreatoblastoma (PB), a neoplasm derived from pancreatic follicular cells, primarily affects the pediatric population. Although infrequent in adults, it is associated with a considerably worse prognosis. Approximately one-third of patients are diagnosed with metastatic disease, with liver metastases being the most prevalent. Diagnosis relies on histopathological alterations including squamous vesicles, positive staining for CK8/CK18/CK19, and nuclear displacement of β-catenin. Additionally, liver metastases demonstrate substantial enhancement during the arterial phase of a contrast-enhanced computed tomography (CT) scan. Surgical resection serves as the principal therapeutic approach for addressing primary lesions and liver metastatic PB. In instances where surgical intervention is not viable, patients may derive benefits from systemic therapy and radiotherapy. This particular case report presents the clinical details of a 27-year-old female patient diagnosed with PB, who subsequently developed multiple liver metastases following a pancreaticoduodenectomy. Genomic examinations revealed the presence of ERBB2 amplification, RAD54L deletion, low TMB-L, and MSS in the patient. Despite the patient undergoing chemotherapy and Her-2 targeted therapy in conjunction with immunotherapy, no reduction in lesion size was observed until the administration of surufatinib. Subsequently, a notable outcome ensued, where the metastatic lesions were effectively excised via surgical intervention. Surufatinib has demonstrated a progression-free survival (PFS) of no less than 14 months, and the patient's survival has endured for a duration of 33 months. This indicates the potential efficacy of surufatinib as a viable therapeutic alternative for adult patients afflicted with PB.

Fusion genes in pancreatic tumors

Gene fusions and rearrangements play a crucial role in tumor biology. They are rare events typically detected in KRAS wild-type (WT) pancreatic tumors. Their identification can inform clinical management by enabling precision oncology, as fusions involving BRAF, FGFR2, RET, NTRK, NRG1, and ALK represent actionable targets in KRAS-WT cancers, and serve diagnostic purposes since fusions involving PRKACA/B represent the diagnostic hallmark of intraductal oncocytic papillary neoplasms (IOPNs). Although they are rare, the therapeutic and diagnostic importance of these genomic events should not be underestimated, highlighting the need for quality-ensured molecular diagnostics in the management of cancer. Herein we review the existing literature on the role of fusion genes in pancreatic tumors and their clinical potential as effective biomarkers and therapeutic targets.

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.

Rare Non-Neuroendocrine Pancreatic Tumours

The most common tumour of the pancreas is ductal adenocarcinoma (PDAC). It remains one of the most lethal non-neuroendocrine solid tumours despite the use of a multi-approach strategy. Other, less-common neoplasms, which are responsible for 15% of pancreatic lesions, differ in treatment and prognosis. Due to the low incidence rate, there is a lack of information about the rarest pancreatic tumours. In this review, we described six rare pancreatic tumours: intraductal papillary mucinous neoplasm (IPMN), mucinous cystadenoma (MCN), serous cystic neoplasm (SCN), acinar cell carcinoma (ACC), solid pseudopapillary neoplasm (SPN) and pancreatoblastoma (PB). We distinguished their epidemiology, clinical and gross features, covered the newest reports about courses of treatment and systematised differential diagnoses. Although the most common pancreatic tumour, PDAC, has the highest malignant potential, it is still essential to properly classify and differentiate less-common lesions. It is vital to continue the search for new biomarkers, genetic mutations and the development of more specific biochemical tests for determining malignancy in rare pancreatic neoplasms.

Pancreatoblastoma in previously pancreatic pseudocysts in a 14-year-old female: a case report

Pancreatoblastoma is a rare tumor characterized by uncontrolled growth of pancreatic epithelial cells with a mix of squamous nests and acinar differentiation. Diagnostic modalities include abnormal liver enzyme, pancreatic enzyme, and imaging findings. Treatment options include surgical resection, sometimes combined with chemotherapy, depending on the tumor’s size and grade. We reported a pancreatoblastoma in a 14-year-old female with prior pancreatic pseudocysts. The transformation from pseudocysts to pancreatoblastoma is believed to be caused by the heterozygosity molecular loss on the 11p chromosome and several genetic mutations. Magnetic resonance cholangiopancreatography showed a well-defined, heterogeneous mass in the pancreatic head, with 70% of the mass composed of cysts. A partial pancreatectomy was performed because a complete pancreatectomy may harm the adjacent structures. However, a complete resection combined with chemoradiation may be the best option for long-term survival and complete remission. In this case, she was disease-free until 30 months after the chemotherapy protocol.

Adult Pancreatoblastoma: Report of 3 new Cases With Genetic Diversity and Autopsy Findings

We report the histopathological, immunohistochemical (IHC), and molecular findings in 3 patients with adult pancreatoblastoma, including 2 with autopsy features. The tumors were located in the tail and body of the pancreas, and the 2 autopsy examinations revealed liver and lung metastases. Histopathologically the neoplasms were composed of solid epithelial elements with nested or trabecular growth patterns, fibrous stroma, and squamoid clusters. Keratin 19 was positive mainly in squamoid corpuscles, and trypsin or chymotrypsin was positive in the acinar component. Neuroendocrine differentiation was observed in all tumors, and nuclear β-catenin expression in 2 tumors. Despite nuclear β-catenin expression, CTNNB1 mutation was found only in tumor 2. APC mutation was detected in tumor 1, and SMAD4 as well as MEN1 mutations in tumor 3. This last tumor also revealed chromosomal instability with many chromosomal losses and gains. The follow-up showed regional or distant metastases in all patients. Two patients died of disease after 3 and 26 months of follow-up and 1 patient is alive with no evidence of disease 6 years and 2 months after surgery. Adult pancreatoblastoma can display genetic heterogeneity, diverse histological appearance, and overlapping IHC findings. As a result, the differential diagnosis with other adult pancreatic tumors, such as acinar cell carcinoma, neuroendocrine neoplasm, solid pseudopapillary neoplasm, and mixed tumors may be challenging, especially when dealing with limited tumor tissue. The identification of squamoid corpuscles is essential for diagnosis. Although molecular findings might provide useful information, the integration of clinical, radiological, and histopathological findings is essential in pancreatoblastoma diagnosis.

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.

MCL1 as putative target in pancreatoblastoma

Pancreatoblastoma (PB) is a rare tumor of the pancreas. In case of metastases, the treatment options are sparse and targeted approaches are not developed. We here evaluate MCL1 amplification as a putative target in PB.

Thirteen samples from adult (10/13) and pediatric patients (3/13) were collected. Three of these samples had been previously subjected to whole-exome sequencing (2 cases) or whole-genome sequencing (1 case) within a precision oncology program (NCT/DKTK MASTER), and this analysis had shown copy number gains of MCL1 gene. We established a fluorescence in situ hybridization (FISH) test to assess the copy number alterations of MCL1 gene in 13 formalin-fixed paraffin-embedded PBs, including the 3 cases assessed by genome sequencing. FISH analysis showed the amplification of MCL1 in 2 cases (both were adult PB), one of which was a case with the highest copy number gain at genomic analysis. In both cases, the average gene copy number per cell was ≥ 5.7 and the MCL1/1p12 ratio was ≥ 2.4. Our data support MCL1 as a putative target in PB. Patients with MCL1-amplified PB might benefit from MCL1 inhibition. Sequencing data is useful to screen for amplification; however, the established FISH for MCL1 can help to determine the level and cellular heterogeneity of MCL1 amplification more accurately.

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.

Pancreatoblastoma in children: EXPeRT/PARTNER diagnostic and therapeutic recommendations

Pancreatoblastoma (PBL) is a rare malignant epithelial neoplasm that affects typically young children. Signs related to advanced upper-abdominal tumor accompanied by elevated serum α-fetoprotein levels in a young child suggest PBL, however histopathological confirmation is mandatory. The mainstay of the treatment is a complete surgical resection. Unresectable and/or metastatic PBL may become amenable to complete delayed surgery after neoadjuvant chemotherapy. This manuscript presents the international consensus recommendations for the diagnosis and treatment of children with PBL, established by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the EU-funded PARTNER (Paediatric Rare Tumors Network - European Registry) project.

Case Report: Two Cases of Metastatic Pancreatoblastoma in Adults: Efficacy of Folfirinox and Implication of the Wnt/β-Catenin Pathway in Genomic Analysis

Pancreatoblastomas are unfrequent tumors usually found in children. We report two cases of metastatic pancreatoblastomas observed in young women. A systemic chemotherapy (FOLFIRINOX regimen) was associated with a disease control in one case and a partial response in the second with an improvement of general status for both. A high-throughput sequencing of the tumor described in both cases alteration in the Wnt/β-catenin pathway: a mutation in CTNNB1 (exon 3, c.110C>G, p.S37C, reported as a hotspot in COSMIC) in one case and a homozygous loss associated with breakage targeting APC (5q22.2) in the second.

A Rare Case of Pancreatoblastoma with Intracranial Seeding

BACKGROUND

Pancreatoblastoma is an extremely rare neoplasm that accounts for 0.5% of all pancreatic exocrine tumors. These rare entities typically manifest in the pediatric population but can rarely occur in adults. Systemic seeding has been described before but intracranial metastasis in adults has yet to be described.

CASE DESCRIPTION

A 28-year-old woman with a history of pancreatoblastoma that had been in remission for 51 months after treatment with cisplatin, doxorubicin (Adriamycin), and etoposide had presented to the emergency room with chronic recurrent headaches. Conservative management of the headaches failed, which led to a diagnostic workup with magnetic resonance imaging of the brain. Magnetic resonance imaging demonstrated a well-circumscribed solitary cerebellar lesion. Metastatic disease was suspected, and the patient underwent suboccipital craniotomy for tumor resection with adjuvant gamma knife radiosurgery.

CONCLUSIONS

Central nervous system seeding of pancreatoblastoma is rare, and the available evidence suggests that the strategy we used could be adequate for treating such occurrences.