Adult pancreatoblastoma: A case report and review of the literature

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.

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.

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.

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.

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.

Successful treatment of metastatic pancreatoblastoma in an adult with autologous hematopoietic cell transplant

BACKGROUND

Pancreatoblastoma is a rare pediatric malignant neoplasm characterized by its histological resemblance to fetal pancreatic tissue and poor clinical outcomes. Preoperative diagnosis of the neoplasm is difficult due to its rarity, variable clinical presentation, and its lack of distinct laboratory markers. Current mainstay of treatment is surgical resection of the tumor, although a standard of care has not yet been established.

METHODS

Data were collected on one patient admitted to the University of Virginia Hospital System. Radiology, hematopoietic cell transplant, and biopsy data were collected according to the best clinical practice.

RESULTS

Herein, we describe the case of an adult patient with pancreatoblastoma treated with high-dose chemotherapy and autologous peripheral blood hematopoietic cell transplantation. To the authors' knowledge, this is the first documented successful treatment of pancreatoblastoma using autologous hematopoietic cell transplantation in the United States, and the first successful treatment in an adult patient worldwide.

CONCLUSIONS

While it is difficult to draw conclusions based on a single case, we would like to highlight the success of this treatment modality in the management of our patient with a 51-month remission and open further discussion into exploring the use of autologous hematopoietic cell transplantation for pancreatoblastoma. Our patient is currently living 57 months after diagnosis despite the average survival rate being less than 18 months.

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.

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.

Systemic Chemotherapy for Advanced Rare Pancreatic Histotype Tumors: A Retrospective Multicenter Analysis

OBJECTIVES

Two issues were put forth by clinicians in the management of the advanced stages of rare variants of pancreatic ductal adenocarcinoma and other exocrine histotypes with peculiar clinical and pathological features: Do chemotherapy regimens recommended in pancreatic ductal adenocarcinoma patients have a clinical activity in rare pancreatic tumors? Or should other chemotherapy combinations be considered in this subset of patients?

METHODS

We conducted a multicenter retrospective study that collected data from 2005 to 2016 at 14 Italian cancer centers with the aim to evaluate tumor response and time to progression for first- and second-line and overall survival.

RESULTS

Of approximately 4300 exocrine pancreatic cancer patients, 79 advanced cases affected by rare histological types were identified, with pancreatic acinar cell cancer (n = 23), pancreatic adenosquamous cancer (n = 16), and mucinous cystic neoplasm with an associated invasive mucinous cystadenocarcinoma (n = 15) most represented. Survival analyses for each subgroup in relation with the different chemotherapy regimens showed the lack of statistical significance correlations.

CONCLUSIONS

Because of the lack of clinical trials in patients affected by these rare pancreatic histotypes, only their molecular classification would help clinicians in future therapeutic choice.

Adult pancreatoblastoma: A case report and clinicopathological review of the literature

PURPOSE

Our purpose was to report a case of adult pancreatoblastoma, and review the literature in order to assist clinicians in the management of the disease.

MATERIALS AND METHODS

The demographic, clinical, and imaging findings of 41 patients with pathologically proven pancreatoblastoma from 1986 to 2017 identified in PubMed were reviewed. The key words used for searching PubMed were: "pancreatoblastoma", "pancreatic tumor", and "adult pancreatoblastoma." We also reported the details of a case of adult pancreatoblastoma treated at our institution.

RESULTS

We identified 41 cases of adult pancreatoblastomas, and the mean age at diagnosis was 41.4 ± 17.4 years. Pancreatoblastomas occurred in the pancreatic head in 48.4% of patients, and in 39.0% of cases the tumor was >8 cm in diameter at diagnosis. Patient age and tumor size were similar between males and females (P = 0.59; P = 0.32, respectively). Metastases was present in 17 of the 41 adult patients (41.5%). No significant difference in age, sex, tumor size, and tumor location was found between patients with and without metastases (P = 0.57, 0.58, 0.64, 0.39, respectively).

CONCLUSION

Preoperative diagnosis of adult pancreatoblastoma is difficult because of the heterogeneous, variable cellular differentiation and atypical clinical and imaging features. A pancreatoblastoma should be considered when tumors in the pancreas are solid and cystic.

A population-based analysis of a rare oncologic entity: Malignant pancreatic tumors in children

PURPOSE

To examine the clinicopathological characteristics and prognosis of pediatric patients with malignant pancreatic tumors in a population-based cohort.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant pancreatic tumors, diagnosed between 1973 and 2013. Kaplan-Meier analysis was performed to determine median and five-year overall survival (OS) rates. Univariate survival analysis was executed using the log-rank test. Cox proportional hazards model was used to identify variables independently associated with mortality.

RESULTS

A total of 114 patients with pancreatic malignancies were identified. Median patient age was 16years and the majority of patients were white (64%) females (61.4%). The most prevalent histologic subtype was neuroendocrine tumors (35.1%), whereas pancreatoblastoma was more common during the first decade of life (P<0.001). Distant metastases were noted in 41.7% of the patients, while 33.3% and 25% had localized and regional disease respectively. Five-year OS rates were 77%, 66.4% and 64.8% for patients with pancreatoblastoma, neuroendocrine and epithelial tumors respectively. No death was observed in the solid pseudopapillary tumor group. Only history of having cancer-directed surgery (CDS) was significantly associated with lower overall mortality (HR: 5.1, 95% CI: 2.1, 12.4).

CONCLUSION

Pancreatic malignancies are rare in children. Their prognosis is variable and only CDS was independently associated with superior survival.

EVIDENCE RATING/CLASSIFICATION

Prognosis study, Level II.

Pancreatoblastoma: an unusual diagnosis in an adult patient

The authors describe a 31-year-old man admitted due to progressive weight loss, diarrhea and massive hepatomegaly. Laboratory data showed anemia (haemoglobin 11.7 g/dl), abnormal liver tests (total bilirubin 1.4 g/dl, aspartate aminotransferase 70 U/l, alanine aminotransferase 37 U/l and alkaline phosphatase 520 U/l). Abdominal ultrasound (US) displayed a large heterogeneous liver with a segment IV 25 mm nodule. Magnetic resonance revealed a 4 cm pancreatic tail mass and several liver nodules consistent with metastasis. The patient underwent an endoscopic ultrasound (EUS) with fine needle aspiration (FNA) from the pancreatic mass and liver metastasis with cytological evaluation consistent with a pancreatoblastoma, later confirmed through a percutaneous US-guided liver biopsy. During the inpatient period, liver function deteriorated and acute kidney injury developed. Severe progressive cachexia was observed. The patient was discharged on renal replacement therapy and palliative care. Death occurred 3 months after diagnosis. Pancreatoblastoma is an uncommon pancreatic malignant epithelial cancer of the pancreas, typically occurring in the paediatric population. Adult pancreatoblastoma is extremely rare, with about 40 cases reported in the literature and generally presenting a more aggressive biologic and clinical behaviour. Surgical resection is the treatment of choice, but most cases are detected in advanced stages. This case underlines the ability to establish a pancreatoblastoma cytology-based diagnosis with EUS-FNA, and confirms the associated poor outcome.

Nonductal Pancreatic Cancers

Nonductal pancreatic neoplasms, including solid pseudopapillary neoplasms, acinar cell carcinomas, and pancreatoblastomas, are uncommon. These entities share overlapping gross, microscopic, and immunohistochemical features, such as well-demarcated solid neoplasms, monotonous cellular tumor cells with little intervening stroma, and abnormal beta-catenin expression. Each tumor also has unique clinicopathologic characteristics with diverse clinical behavior. To differentiate nonductal pancreatic neoplasms, identification of histologic findings, such as pseudopapillae, acinar cell features, and squamoid corpuscles, is important. Immunostainings for acinar cell or neuroendocrine markers are helpful for differential diagnosis. This article describes the clinicopathologic and immunohistochemical features of nonductal pancreatic cancers.