Adult pancreatoblastoma: Current concepts in pathology

Diagnosis, treatment, and prognosis of adult pancreatoblastoma

BACKGROUND

Pancreatoblastoma (PB) is one of the rare malignant tumors that typically occurs in children. Cases of PB in adults are highly unusual. This disease often presents with subtle symptoms and lacks characteristic clinical manifestations, leading to diagnostic challenges.

OBJECTIVE

This study integrates the relevant literature on adult PB, conducting data analysis on clinical features, laboratory and imaging results, pathological characteristics, and treatments according to inclusion and exclusion criteria. Kaplan-Meier univariate analysis and Log-rank tests are employed to analyze survival data from adult PB follow-up, exploring factors influencing prognosis.

RESULTS

A total of 65 articles were included, encompassing 103 cases of adult PB. The average age of PB patients was 41.78 years (range 19-81 years), and the male-to-female ratio was 1.06:1. Patients frequently presented with abdominal pain as the initial symptom. Laboratory results lacked specificity and imaging findings often presented as large, well-defined masses. PB exhibited distinctive pathological features, including squamous corpuscles (n = 76, 89.41%) and acinar differentiation (n = 34, 40%), with frequent positive expression of Trypsin, Chymotrypsin, and AACT (Alpha-1-Antichymotrypsin). APC (Adenomatous Polyposis Coli) gene mutation was the most common molecular alteration in adult PB. During the follow-up period, 43.59% of patients died (range 3 days to 348 months). The primary factors affecting prognosis were the presence of metastasis (χ2 = 3.996, p = 0.046) and incomplete surgical resection (χ2 = 5.586, p = 0.018), with mean survival times of 48 months and 27 months, respectively.

CONCLUSIONS

PB in adults is an invasive tumor. The key to distinguishing PB from other pancreatic tumors lies in recognizing its unique pathological feature, the squamous corpuscles. Timely and complete surgical resection is the preferred treatment following diagnosis. Patients with incomplete resection or the presence of lymph nodes or (and) distant metastases have a poor prognosis.

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.

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.

Comprehensive review of pancreatic acinar cell carcinoma: epidemiology, diagnosis, molecular features and treatment

Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.

Association between Pancreatoblastoma and Familial Adenomatous Polyposis: Review of the Literature with an Additional Case

BACKGROUND

Adult pancreatoblastoma (PBL) is a rare pancreatic malignancy, with recent evidence suggesting a possible link to familial adenomatous polyposis (FAP). This study aims to review the latest evidence and explore a possible association between adult PBL and FAP.

METHODS

Two independent literature reviews were conducted: (1) on PBL and FAP, and (2) on PBL in the adult population not diagnosed with FAP.

RESULTS

Out of 26 articles on PBL and FAP screened, 5 were selected for systematic review, including 1 additional case. We identified eight FAP-related PBL cases, with a median age of 40 (IQR: 34-50). Of these, seven (87%) occurred in adults. We found 65 cases of adult PBL not FAP-related; thus, 7 out of 65 cases (10.7%) of adult PBL reported in the literature are associated with a clinical diagnosis of FAP or were carriers of APC germline pathogenic variants (GPVs).

CONCLUSION

Data suggest a non-random association between adult PBL and FAP. Further research is essential to optimise surveillance protocols and develop more effective treatment strategies.

Adult Pancreatoblastoma: An Uncommon Pancreatic Malignancy

In this report we present a rare case of pancreatoblastoma in an adult patient. Whilst they are amongst the most common malignant pancreatic tumours in children, presentations in adults are exceedingly rare, with a small number of reported cases. Its presentation is often non-specific in terms of clinical examination, and subsequent imaging can show similar findings to those seen in benign neoplasms. This report highlights the difficulty of achieving a diagnosis and subsequent treatment of such an uncommon disease. Biopsy and resultant histology are essential in diagnosis and surgical resection remains the preferred modality of treatment. However, the use of chemotherapy and its efficacy in adults remains unclear, and the prognosis documented in existing literature for adults is worse when compared to paediatric presentations. This case emphasises the need to consider pancreatoblastoma as a differential diagnosis when suspecting pancreatic or abdominal malignancies to achieve early detection and diagnosis, in order to provide optimal treatment and improve patient outcomes.

Pancreatoblastoma in Elderly Adults: Report of Two Patients

Introduction. Pancreatoblastoma is a rare malignant epithelial neoplasm of the pancreas, which often shows multiple lines of differentiation, but is defined by neoplastic cells with acinar differentiation and characteristic squamoid nests. Pediatric patients are most commonly affected, and although a subset is known to occur in adults, the diagnosis is rarely considered in elderly adults. Methods. The clinicopathologic features of two cases of pancreatoblastoma in elderly patients were examined. Results. Two patients (age 80 and 81 years) presented with pancreatoblastoma, including one with early-stage pancreatic disease and one with liver metastasis. Biopsies and one pancreatic resection specimen showed characteristic histomorphologic features, including prominent acinar differentiation and abundant squamoid nests. Both cases had complete loss of SMAD4 (DPC4) immunolabeling. Next generation sequencing was performed on one case and revealed copy number loss of chromosome 11p and 9p21 (CDKN2A/B) and pathogenic or likely pathogenic variants in APC, SMAD4, and PIK3CA. The APC and SMAD4 variants occurred at allele frequencies suggestive of germline mutations, raising the possibility that this patient may have an inherited cancer predisposition syndrome. Conclusions. We present two cases which extend the upper age limit for reported pancreatoblastoma, including one with genetic findings suggestive of an inherited cancer predisposition syndrome.

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.

Metachronous metastatic pancreatoblastoma to the liver in an elderly patient misdiagnosed as pancreatic acinar cell carcinoma

A woman in her 80s was evaluated for a liver mass. She had a history of what was reported as pancreatic acinar cell carcinoma resected with a pancreatoduodenectomy 10 years prior at another institution. Liver biopsy showed metastatic pancreatoblastoma (PB) and staging imaging showed no evidence of additional metastatic disease. She underwent laparoscopic non-anatomic partial hepatectomy and recovered uneventfully. The liver pathology was reviewed along with slides from her initial pancreatoduodenectomy, and both were noted to be consistent with PB. PB contains similar histological characteristics to pancreatic acinar cell carcinoma. Distinguishing between the two diagnoses is critical for accurately defining the prevalence, clinical course and prognosis associated with PB.

Solid pseudopapillary neoplasm of the pancreas

Solid pseudopapillary neoplasms are rare. This article reviews the clinical and pathologic features of solid pseudopapillary neoplasm of the pancreas, including the epidemiology, cytology, molecular pathology, differential diagnosis, treatment, and prognosis. Solid pseudopapillary neoplasms are low-grade malignant tumours of the pancreas characterized by poorly cohesive epithelial cells with solid and pseudopapillary patterns. Solid pseudopapillary neoplasms occur predominantly in young women. Although solid pseudopapillary neoplasms can occur throughout the pancreas, they arise slightly more frequently in the tail of the pancreas. The aetiology is unknown. Extremely rare cases have been reported in the setting of familial adenomatous polyposis. There are no symptoms unique to solid pseudopapillary neoplasms, however, the most common symptom is abdominal pain or discomfort. The features of solid pseudopapillary neoplasms on computed tomography imaging are indicative of the pathologic changes within the tumour. Typically, well-demarcated masses with variably solid and cystic appearances. Microscopically, these tumours are composed of epithelial cells forming solid and pseudopapillary structures, frequently undergoing haemorrhagic cystic degeneration. Typically, these tumours express nuclear and/or cytoplasmic β-catenin. Almost all solid pseudopapillary neoplasms harbour mutations in exon 3 of CTNNB1, the gene encoding β-catenin. The overall prognosis is excellent, and most patients are cured by complete surgical resection.