Acinar cell carcinoma of the pancreas: clinical and computed tomography manifestations

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.

Treatment characteristics and outcomes of pure Acinar cell carcinoma of the pancreas - A multicentric European study on radically resected patients

BACKGROUND

Acinar cell carcinomas (ACC) belong to the exocrine pancreatic malignancies. Due to their rarity, there is no consensus regarding treatment strategies for resectable ACC.

METHODS

This is a retrospective multicentric study of radically resected pure pancreatic ACC. Primary endpoints were overall survival (OS) and disease-free survival (DFS). Further endpoints were oncologic outcomes related to tumor stage and therapeutic protocols.

RESULTS

59 patients (44 men) with a median age of 64 years were included. The median tumor size was 45.0 mm. 61.0% were pT3 (n = 36), nodal positivity rate was 37.3% (n = 22), and synchronous distant metastases were present in 10.1% of the patients (n = 6). 5-Years OS was 60.9% and median DFS 30 months. 24 out of 31 recurred systemically (n = 18 only systemic, n = 6 local and systemic). Regarding TNM-staging, only the N2-stage negatively influenced OS and DFS (p = 0.004, p = 0.001). Adjuvant treatment protocols (performed in 62.7%) did neither improve OS (p = 0.542) nor DFS (p = 0.159). In 9 cases, radical resection was achieved following neoadjuvant therapy.

DISCUSSION

Radical surgery is currently the mainstay for resectable ACC, even for limited metastatic disease. Novel (neo)adjuvant treatment strategies are needed, since current systemic therapies do not result in a clear survival benefit in the perioperative setting.

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

New treatment insights into pancreatic acinar cell carcinoma: case report and literature review

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic malignancy with unique clinical, molecular, and morphologic features. The long-term survival of patients with PACC is substantially better than that of patients with ductal adenocarcinoma of the pancreas. Surgical resection is considered the first choice for treatment; however, there is no standard treatment option for patients with inoperable disease. The patient with metastatic PACC reported herein survived for more than 5 years with various treatments including chemotherapy, radiotherapy, antiangiogenic therapy and combined immunotherapy.

Pancreatic acinar cell carcinoma: A comprehensive review

Acinar cell carcinoma (ACC) is a rare pancreatic malignancy with distinctive clinical, molecular, and morphological features. The long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma patients. As there are no significant patient series about ACCs, our understanding of this illness is mainly based on case reports and limited patient series. Surgical resection is the treatment of choice for patients with the disease restricted to one organ; however, with recent breakthroughs in precision medicine, medicines targeting the one-of-a-kind molecular profile of ACC are on the horizon. There are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not possible. As a result of shared genetic alterations, ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal carcinomas. The role of neoadjuvant or adjuvant chemoradiotherapy has not been established. This article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

Clinical Analysis of Acinar Cell Carcinoma of the Pancreas: A Single-Center Experience of 45 Consecutive Cases

Backgrounds:

Acinar cell carcinoma of the pancreas is a rare malignancy, and its features remain unclear. We aimed to analyze the clinical characteristics, treatment and prognosis of acinar cell carcinoma with our institutional case series.

Methods:

Patients diagnosed with acinar cell carcinoma in our hospital between 2005 and 2019 were reviewed. Investigations on clinicopathological features, treatment details and long-term survival were performed.

Results:

A total of 45 pathologically confirmed acinar cell carcinomas were identified. The median age at diagnosis was 58 years with a male-to-female ratio of 3.1:1. There were 24 (53.3%) localized, 5 (11.1%) locally advanced and 16 (35.6%) metastatic cases, with a pancreatic head-to-body/tail ratio of 1:1.4 for all the primary lesions. In the localized group, there were 10 pancreatoduodenectomy, 12 distal pancreatectomy, 1 total pancreatectomy, and 1 distal pancreatectomy combined with proximal gastrectomy. Among the locally advanced and metastatic cases, 13 patients received chemotherapy, 1 received concurrent radiochemotherapy, 1 underwent synchronous resection of primary tumor and liver metastasis, 1 underwent palliative operation, 1 underwent exploratory laparotomy, and 4 required no treatment. The median overall survival of this series was 18.9 months with a 5-year survival rate of 19.6%. Moreover, the resected acinar cell carcinoma patients were associated with prolonged survival compared with the unresected cases (36.6 vs. 8.5 months, P < 0.001).

Conclusions:

Surgical resection could improve the long-term survival of acinar cell carcinoma patients, which might also improve the prognosis of selected metastatic cases. Large-scale studies are needed to further clarify the biological behavior and clinical features, and to seek the optimal treatments.

Artificial intelligence in gastrointestinal radiology: A review with special focus on recent development of magnetic resonance and computed tomography

Artificial intelligence (AI), particularly the deep learning technology, have been proven influential to radiology in the recent decade. Its ability in image classification, segmentation, detection and reconstruction tasks have substantially assisted diagnostic radiology, and has even been viewed as having the potential to perform better than radiologists in some tasks. Gastrointestinal radiology, an important subspecialty dealing with complex anatomy and various modalities including endoscopy, have especially attracted the attention of AI researchers and engineers worldwide. Consequently, recently many tools have been developed for lesion detection and image construction in gastrointestinal radiology, particularly in the fields for which public databases are available, such as diagnostic abdominal magnetic resonance imaging (MRI) and computed tomography (CT). This review will provide a framework for understanding recent advancements of AI in gastrointestinal radiology, with a special focus on hepatic and pancreatobiliary diagnostic radiology with MRI and CT. For fields where AI is less developed, this review will also explain the difficulty in AI model training and possible strategies to overcome the technical issues. The authors’ insights of possible future development will be addressed in the last section.

Survival Outcomes of Acinar Cell Pancreatic Cancer: A National Cancer Database Analysis

OBJECTIVES

Acinar cell pancreatic carcinomas (ACPCs) are rare neoplasms accounting for 1% to 2% of pancreatic tumors in adults. The objective of this study is to evaluate the benefit of chemotherapy in the adjuvant setting in resected ACPC and in the palliative setting for metastatic ACPC.

METHODS

Data were obtained from all US hospitals that contributed to the National Cancer Database between 2004 and 2014. Cases were identified using the histology code 8550.

RESULTS

A total of 593 patients with ACPC were identified. The mean age was 64.4 years (range, 18-90 years), with a male preponderance (72.8%, n = 432). Localized stage disease comprised 52.3% (n = 310) of patients. Among localized ACPC patients, 88.0% (n = 191) underwent surgery and 50.6% (n = 91) received adjuvant chemotherapy. The 5-year overall survival in those who received adjuvant treatment was slightly higher than those who did not receive adjuvant treatment (46.7% vs 44.8%, P = 0.3271). Among advanced-stage ACPC patients, 67.6% received chemotherapy, which translated into improved 5-year overall survival compared with no chemotherapy (8.1% vs 0%, P < 0.0001).

CONCLUSIONS

Chemotherapy in the palliative setting for advanced-stage ACPC patients was associated with improved survival. Adjuvant therapy did not translate into significant survival benefit.

Clinical characteristics and treatment analysis of pancreatic acinar cell carcinoma: A single institutional comparison to pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic acinar cell carcinoma (PACC) is a rare malignancy that accounts for less than 1% of primary pancreatic neoplasms. Currently, the lack of large-scale clinical studies limits our understanding of PACC. The aim of this study was to investigate the clinical characteristics and prognosis of PACC.

METHODS

In a retrospective analysis, 52 patients with PACC and 355 patients with pancreatic ductal adenocarcinoma (PDAC) who underwent surgical interventions were evaluated. Clinical characteristics and treatment outcomes were compared between the two groups.

RESULTS

The mean age was lower for patients with PACC than for those with PDAC (mean: 50.8 ± 10.9 versus 59.4 ± 10.9 years; p < 0.001). Except for alpha-fetoprotein (AFP), tumour markers were also lower in the PACC group than the PDAC group. In regard to tumour characteristics, maximum diameters of the primary tumour [median (range): 5.0 cm (1.0-18.2 cm) versus 3.5 cm (0.6-15.0 cm); p < 0.001] and hepatic metastatic lesions [6.7 cm (1.5-12.6 cm) versus 1.2 cm (0.3-3.3 cm); p < 0.001] were larger in patients with PACC than patients with PDAC, but vascular invasion [23.1% (12/52) versus 35.5% (126/355); p = 0.044] and perineural invasion [7.7% (4/52) versus 56.1% (199/355); p < 0.001] were more common in patents with PDAC than in patients with PACC. For treatment, radical resection was performed in 57.7% of patients with PACC, which increased the 5-year survival rate to 31.8%. In regard to prognosis, the 5-year survival rate was 21.4% for PACC and 9.7% for PDAC (p < 0.0001).

CONCLUSIONS

PACC is more indolent than PDAC, which makes early diagnosis more difficult. Although the stage may be advanced at diagnosis, the overall survival (OS) of PACC is much better than that of PDAC, and the prognosis greatly improves after radical resection.

Pancreatic acinar cell carcinoma with a ductal adenocarcinoma component: a case report and analysis of the histogenesis of the tumor

BACKGROUND

Pancreatic cancer composed of acinar cell carcinoma (ACC) and ductal adenocarcinoma (DAC) is rare, and the clinicopathological characteristics of ACC with DAC have yet to be elucidated. Herein, we report a case of ACC with a DAC component of the pancreas and examined the histogenesis of this tumor.

CASE PRESENTATION

A 69-year-old man was admitted to our hospital complaining of appetite loss, constipation, epigastric dull pain, and jaundice. Abdominal computed tomography and magnetic resonance cholangiopancreatography revealed a pancreatic head tumor with dilatation of the bile duct and the distal main pancreatic duct. Under the diagnosis of pancreatic head cancer, a pancreatoduodenectomy was performed. The histology of the resected tumor consisted of mainly ACC with a focus of DAC, which was confirmed by mucin staining and immunohistochemistry for antigens such as BCL10, trypsin, Smad4, p16, p53, and MUC1. There was histological transition between the components of ACC and DAC, and immunostaining of the transitional zone showed equivocal results for the antigens. KRAS was wild-type in both ACC and DAC. The patient was treated with adjuvant chemotherapy with S-1 for 1 year. No evidence of recurrence or metastasis was observed after 9 years of follow-up.

CONCLUSIONS

A rare case of pancreatic ACC with a DAC component in a patient with long-term survival after surgery was reported. Immunohistochemical and molecular analysis indicated that DAC might have arisen from ACC through transdifferentiation in this case.

Acinar cell carcinoma of the pancreas: a clinicopathologic and cytomorphologic review

Acinar cell carcinoma (ACC) is a rare malignancy of the pancreas with unique clinical, molecular, and morphologic characteristics. Clinically, these cancers can present with hypersecretory syndrome caused by the release of lipase into the circulation. Surgical resection is the treatment of choice for patients with organ-confined disease; however, with recent advances in precision medicine, therapies targeting the distinct molecular profile of ACC are on the horizon. Cytomorphologic features of ACC have been well described in the literature; and in conjunction with available clinical data and appropriate ancillary studies, an accurate diagnosis can be rendered in most instances. The aim of the current article is to present a comprehensive review of ACC based on available literature while attempting to shed light on some of its key histologic and cytologic characteristics.

Computed tomography features of acinar cell carcinoma of the pancreas

PURPOSE

To report the computed tomography (CT) features of pancreatic acinar cell carcinoma (ACC) and identify CT features that may help discriminate between pancreatic ACC and pancreatic ductal adenocarcinoma (PDA).

MATERIALS AND METHODS

The CT examinations of 20 patients (13 men, 7 women; mean age, 66.5±10.7 [SD] years; range: 51-88 years) with 20 histopathologically proven pancreatic ACC were reviewed. CT images were analyzed qualitatively and quantitatively and compared to those obtained in 20 patients with PDA. Comparisons were performed using univariate analysis with a conditional logistic regression model.

RESULTS

Pancreatic ACC presented as an enhancing (20/20; 100%), oval (15/20; 75%), well-delineated (14/20; 70%) and purely solid (13/20; 65%) pancreatic mass with a mean diameter of 52.6±28.0 (SD) mm (range: 24-120mm) in association with visible lymph nodes (14/20; 70%). At univariate analysis, well-defined margins (Odds ratio [OR], 7.00; P=0.005), nondilated bile ducts (OR, 9.00; P=0.007), visible lymph nodes (OR, 4.33; P=0.028) and adjacent organ involvement (OR, 5.67; P=0.02) were the most discriminating CT features to differentiate pancreatic ACC from PDA. When present, lymph nodes were larger in patients with pancreatic ACC (14±4.8 [SD]; range: 7-25mm) than in those with PDA (8.8±4.1 [SD]; range: 5-15mm) (P=0.039).

CONCLUSION

On CT, pancreatic ACC presents as an enhancing, predominantly oval and purely solid pancreatic mass that most frequently present with no bile duct dilatation, no visible lymph nodes, no adjacent organ involvement and larger visible lymph nodes compared to PDA.

Pictorial Review of Rare Pancreatic Tumors and Tumor-Like Lesions

췌장에는 다양한 종류의 종양 및 종양 유사 병변들이 생길 수 있다. 이 가운데, 췌장선암은 췌장의 가장 흔한 종양으로서 일반적으로 췌장암이라고 하면 이 종양을 가리킨다. 최근에는 영상 검사의 기술적 진보와 이용이 증가하면서 췌장의 희귀 종양 및 종양 유사 병변들의 발견 빈도가 증가하고 있다. 췌장의 드문 종양 및 종양과 유사한 병변들은 치료 방침과 예후가 췌장선암과 다르기 때문에 이들 질환의 감별은 임상적으로 중요한 의의가 있다. 영상 검사는 포상세포암이나 신경초종 등의 희귀 종양 및 자가면역 췌장염 또는 염증성 거짓종양과 같은 종양 유사 병변들과 췌장선암의 감별 진단에 중요한 역할을 하지만 영상 소견만으로 이들 질환을 정확히 구분하는 것은 한계가 있다. 이 논문에서는 췌장에서 생길 수 있는 희귀 종양 및 종양 유사 병변들의 다양한 영상 소견들과 췌장선암과의 감별에 있어 도움이 되는 특징들을 제시하고자 한다.

Pancreatic Ductal Adenocarcinoma in Remnant Pancreas after Pancreaticoduodenectomy for Acinar Cell Carcinoma: A Case Report

We report a case of a pancreatic ductal adenocarcinoma (PDAC) in the remnant pancreas of a 78-year-old man after pancreaticoduodenectomy for acinar cell carcinoma, a relatively rare pancreatic neoplasm. After diagnosis of pancreatic carcinoma, subtotal stomach-preserving pancreaticoduodenectomy was performed. The pathological diagnosis was acinar cell carcinoma of the pancreas (disease stage IA, pT1, pN0, M0), without regional lymph node invasion. Cancer antigen 19-9 levels gradually increased during the 22 months after surgery, and computed tomography showed two solid tumors, 1.1 and 2.1 cm in diameter, at the site of the remnant pancreas. Endoscopic ultrasound fine-needle aspiration revealed pancreatic ductal adenocarcinoma. The tumor cells were not immunoreactive for trypsin. Both tumors were diagnosed as PDAC of the remnant pancreas. The patient declined curative resection, and chemoradiotherapy was started as alternative treatment. The patient died 28 months after surgery. Because this is an extremely rare case, additional cases and studies are needed in order to clarify its pathogenesis.

Lipase hypersecretion syndrome: A distinct form of paraneoplastic syndrome specific to pancreatic acinar carcinomas

Lipase hypersecretion syndrome (LHS) is a paraneoplastic syndrome seen exclusively as a result of pancreatic acinar cell carcinoma (ACC). In LHS, acinar enzymes (lipase, trypsin and chymotrypsin) which are normally secreted to the duodenum for digestive purposes, are instead released to the blood by the carcinoma cells. In a way, it is "endocrine-ization" of an "exocrine" function. These circulating enzymes, especially lipase, exerts its digestive action on other tissues, especially on the subcutaneous tissues in the pressure poins of legs, creating a picture often mistaken as erythema nodosum or rheumatic nodules. The bone and joints may also be effected, which mostly appears to be secondary to the complications and super-infection of the skin lesions. Eosinophilia also often accompanies this syndrome. The accurate diagnosis of LHS requires the identification of the pancreatic primary as well as its correct classification as acinar because a variety of pancreatic tumors can be associated with skin lesions, ranging from rare metastasis of adenocarcinoma to the necrolytic migratory erythema caused by glucagon-producing neuroendocrine tumors. Towards this differential, the diagnostic characteristics of acinar cell carcinomas that have been better elucidated in the past decade often need to be employed in increasingly smaller specimens and the liver, especially since most LHS cases also have liver metastasis (presumably due to the by-pass of the "first-pass" liver metabolism phenomenon). ACC (and LHS) occur in patients in their 60's. The pancreatic mass is often large, round, demarcated and closely resemble neuroendocrine and solid-pseudopapillary neoplasms but are more atypical/proliferative, and commonly show single prominent nucleoli and a distinctive chromophilia. Immunostaining with trypsin/chymotrypsin, negativity of beta-catenin help in the differential; as a caveat, neuroendocrine differentiation is common in ACCs. In conclusion, LHS is a rare type of paraneoplastic syndrome specific to ACC. The accurate diagnosis requires attention to their subtle diagnostic characteristics.

Underutilization of surgical resection in patients with pancreatic acinar cell carcinoma

BACKGROUND

Pancreatic acinar cell carcinoma (pACC) is a rare malignancy and surgical utilization has been historically low in these patients. Contemporary outcomes for this patient population remain unknown.

METHODS

The 1998-2012 National Cancer Data Base was queried for baseline characteristics in patients with pACC. Patients with potentially operable disease (stage I/II) were grouped by surgical resection. Multivariable logistic regression was used to predict factors associated with resection. Survival was estimated using Kaplan-Meier analysis. A proportional hazards model identified factors associated with overall survival.

RESULTS

980 patients were identified. Mean age at diagnosis was 64 years. Tumors were more common in men (68%), white patients (88%), and within the pancreatic head (57%). Thirty-four percent of patients with localized disease failed to undergo resection. Five-year survival was higher among patients who underwent resection (42% vs. 9%, p < 0.001). In patients with resectable disease, male sex, older age, black race, tumors within the pancreatic head, lower grade tumors and treatment at non-academic centers are associated with failure to undergo surgery.

CONCLUSION

Patients with localized pACC have increased survival after resection. However, in this contemporary analysis, resection continues to be underutilized and new efforts to increase resection rates should be undertaken.

Rare Solid Tumor of the Exocrine Pancreas: A Pictorial Review

Numerous other solid primary neoplasms may arise from the pancreas besides primary ductal adenocarcinomas and neuroendocrine tumors. Although diagnosis can be difficult because of the very low incidence of these tumors, knowledge of several, typical, epidemiologic, biological, and imaging features can help obtain a correct diagnosis. This pictorial review describes the features of solid rare primary pancreatic neoplasms on computed tomography and magnetic resonance imaging focusing on characteristics that can help radiologists differentiate them from classical forms of ductal pancreatic adenocarcinoma and neuroendocrine tumors. Cystic pancreatic neoplasms are beyond the scope of the current review.

MR imaging features of pancreatic acinar cell carcinoma

PURPOSE

This study aimed to report the magnetic resonance imaging (MRI) features of acinar cell carcinoma (ACC) of the pancreas including diffusion-weighted MRI findings.

MATERIALS AND METHODS

The MRI examinations of five patients (3 men, 2 women; median age, 61years) with histopathologically proven ACC of the pancreas were retrospectively reviewed. MR images were analyzed qualitatively (location, shape, homogeneity, signal intensity, vascular involvement and extrapancreatic extent of ACC) and quantitatively (tumor size, apparent diffusion coefficient [ADC] and normalized ADC of ACC).

RESULTS

All ACC were visible on MRI, presenting as an oval pancreatic mass (5/5; 100%), with moderate and heterogeneous enhancement (5/5; 100%), with a median transverse diameter of 43mm (Q₁, 35; Q₃, 82mm; range: 30-91mm). Tumor capsule was visible in 4/5 ACC (80%) and Wirsung duct enlargement in 2/5 ACC (40%). On diffusion-weighted MRI, all ACC (5/5; 100%) were hyperintense on the 3 b value images. Median ADC value of ACC was 1.061×10^-3mm²/s (Q₁, 0.870×10^-3mm²/s; Q₃, 1.138×10^-3mm²/s; range: 0.834-1.195×10^-3mm²/s). Median normalized ADC ratio of ACC was 1.127 (Q₁, 1.071; Q₃, 1.237; range: 1.054-1.244).

CONCLUSIONS

On MRI, ACC of the pancreas presents as a large, oval pancreatic mass with moderate and heterogeneous enhancement after intravenous administration of a gadolinium chelate, with restricted diffusion and a median ADC value of 1.061×10^-3mm²/s on diffusion-weighted MRI. Further studies however are needed to confirm our findings obtained in a limited number of patients.

Small pancreatic ductal carcinomas on triple-phase contrast-enhanced computed tomography: enhanced rims and the pathologic correlation

PURPOSE

To reveal the prevalence of small (≤ 20 mm) pancreatic ductal carcinomas with enhanced rims on triple-phase contrast-enhanced CT and correlate the CT images with the pathologic findings.

MATERIALS AND METHODS

Between April 2005 and April 2016, 45 patients underwent preoperative triple-phase contrast-enhanced CT and were pathologically diagnosed with small pancreatic ductal carcinoma. CT images were independently reviewed by two radiologists. The attenuation values of the enhanced rims, internal areas of the tumors, and surrounding pancreatic parenchyma were compared using Mann-Whitney U test. These areas were also correlated with the pathologic findings. Tumor invasiveness was compared between the tumors with and without enhanced rims using Fisher's exact test.

RESULTS

Enhanced rims were identified in 18 tumors (40%) by consensus between the two reviewers. The enhanced rims showed significantly higher mean attenuation values compared with the internal areas of the tumors (p < 0.001) and surrounding pancreatic parenchyma (p < 0.0086), and were most clearly visualized on equilibrium phase. The enhanced rims pathologically reflected the abundant fibrotic stroma with cancer cells in all tumors. There was no statistically significant difference in tumor invasiveness between the tumors with and without enhanced rims (anterior peripancreatic invasion, p = 0.137; posterior peripancreatic invasion, p = 0.758; portal vein invasion, p = 0.639; and lymph node metastases, p = 0.359).

CONCLUSIONS

Enhanced rims were detected at a rate of 40% in small pancreatic ductal carcinomas and could be an important finding for diagnosis on CT images, but did not suggest a less aggressive nature.

Response of germline BRCA2-mutated advanced pancreatic acinar cell carcinoma to olaparib: A case report

RATIONALE

Pancreatic acinar cell carcinoma (PACC) is a relatively rare malignancy of the exocrine pancreas. BRCA2, a cancer susceptibility gene, has been widely studied in breast and ovarian carcinomas as mutation carriers for this gene are at a high risk for cancer development. Olaparib, an oral poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor, has been approved for the treatment of ovarian cancer with any BRCA 1/2 mutations. Herein, we report the first case of a germline BRCA2-mutated unresectable advanced PACC patient who responded well to olaparib treatment.

PATIENT CONCERNS

A 59-year-old male with a family history of cancer presented with a persistent epigastric dull pain for 3 months.

DIAGNOSIS

The patient was diagnosed with advanced PACC based on computed tomography (CT) scan, laparotomy, and pathology.

INTERVENTIONS

Exploratory laparotomy, intratumoral brachytherapy by radioiodine-125 seeds, modified FOLFIRINOX chemotherapy, and targeted therapy with olaparib were administered.

OUTCOMES

The patient responded well to olaparib until the occurrence of severe adverse drug reactions, he died as a result of multiple organ failure with an overall survival period of 12 months.

LESSONS

As a PARP inhibitor, olaparib has remarkable curative effect not only on breast and ovarian cancers, but also on other malignancies with BRCA mutations. Patients with advanced cancer could benefit from active targeted therapy with improvement in overall survival and quality of life.

Calcified peripancreatic lymph nodes in pancreatic and hepatic tuberculosis mimicking pancreatic malignancy: A case report and review of literature

RATIONALE

Tuberculosis remains a serious menace to the health of people. Isolated hepatic tuberculosis is rare and pancreatic tuberculosis is extremely rare. The preoperative diagnosis of pancreatic tuberculosis remains a great challenge.

PATIENT CONCERNS

A 58-year-old Asian woman was referred to our hospital for evaluation of low back pain for 4 years and abdominal pain for 1 month.

DIAGNOSES

Computed tomography (CT) of the abdomen showed a hypodense mass in the pancreatic head and neck with abundant calcifications, a hypodense lesion in the liver without calcification, peripancreatic lymphadenopathy, calcifications in some lymph nodes. CT-guided fine needle aspiration biopsy of the hepatic lesion was carried out and the cytological examination revealed hepatic tuberculosis.

INTERVENTIONS

The patient was treated with antituberculous therapy for 1 year.

OUTCOMES

Low back pain and abdominal pain disappeared 3 months after initial treatment and after 2 year of follow-up, the patient was asymptomatic.

LESSONS

Our data hint that calcifications in both pancreatic lesions and peripancreatic lymph nodes may suggest pancreatic tuberculosis rather than pancreatic malignancy.

Imaging mimics of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma is the most common primary malignancy of the pancreas. The classic imaging features are a hypovascular mass with proximal ductal dilatation. Different pancreatic pathologies can mimic the imaging appearance of carcinoma including other tumors involving the pancreas (pancreatic neuroendocrine tumors, lymphoma, metastasis, and rare tumors like pancreatic acinar cell carcinoma and solid pseudopapillary tumors), inflammatory processes (chronic pancreatitis and autoimmune pancreatitis), and anatomic variants (annular pancreas). Differentiation between these entities can sometimes be challenging due to overlap of imaging features. The purpose of this article is to describe the common entities that can mimic pancreatic cancer on imaging with illustrative examples and to suggest features that can help in differentiation of these entities.

Acinar cell carcinoma of the pancreas presenting as diffuse pancreatic enlargement: Two case reports and literature review

RATIONALE

Pancreatic acinar cell carcinoma (ACC) is a rare malignant tumor of exocrine pancreas. It is typically a well-marginated large solid mass arising in a certain aspect of the pancreas. Diffuse involvement of ACC in the pancreas is very rare, and may simulate pancreatitis in radiological findings. We report 2 cases of ACC presenting as diffuse enlargement of the pancreas due to tumor involvement without formation of a distinct mass.

PATIENT CONCERNS

The patients consisted of a 41-year-old man with weight loss and a 77-year-old man who was asymptomatic.

DIAGNOSES

Computed tomography (CT) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT showed diffuse enlargement of the pancreas forming a sausage-like shape with homogenously increased FDG activity.

INTERVENTIONS

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) biopsy of the pancreatic lesion was performed.

OUTCOMES

Histopathology results from the pancreas confirmed the diagnosis of pancreatic ACC.

LESSONS

Because diffuse enlargement of the pancreas is a common imaging feature of pancreatitis, recognition of this rare morphologic pattern of ACC is important for radiological diagnosis of this tumor.

Acinar cell carcinoma: a report of 19 cases with a brief review of the literature

Background

Acinar cell carcinoma (ACC) is a relatively rare pancreatic neoplasm with poorly defined prognosis. This study aimed to investigate this rare pancreatic neoplasm through comparing patients with ACC to pancreatic ductal cell adenocarcinoma (DCA).

Methods

Tianjin Medical University Cancer Institute and Hospital pathology database was reviewed from 1995 to 2015, and 19 patients with pathologically confirmed ACC were enrolled while 19 conventional DCA patients assigned randomly as control. Retrospective review and follow-up were performed for each patient. Regression methods were used to identify differences between ACC and DCA.

Results

In our study, most patients suffered from abdominal or back pain, and no lipase hypersecretion syndrome was observed. For ACC, resected cases had better survival than those without resection, and earlier staging was related to longer survival. Resection with postoperative adjuvant therapy had a better outcome than surgery alone. Twelve cases developed recurrence. Compared to DCA, ACC had earlier staging and better survival. The overall 1-, 2-, and 5-year survival rates for patients with ACC were 73.7, 26.3, and 5 %, respectively.

Conclusions

ACC carries a better prognosis than DCA and a similarly high recurrence rate, while surgical resection proved the best first-line approach for it. A well-planned neoadjuvant or adjuvant chemoradiotherapy indeed benefit the patients with ACC.

Pancreatic Acinar Cell Carcinoma

Pancreatic acinar cell carcinoma (ACC) is a rare malignant neoplasm that accounts for 1–2% of all pancreatic neoplasms. Here we report two cases of ACC and describe their clinical features, the therapies used to treat them, and their prognosis. The first patient was a 65-year-old woman who had an abdominal CT scan for a urinary infection. Fortuitously, a rounded and well-delimited corporeal pancreatic tumor was discovered. An endoscopic ultrasound (EUS)-guided fine needle aspiration revealed an ACC. During the puncture, a hypoechoic cavity appeared inside the lesion, corresponding to a probable necrotic area. Treatment consisted of a distal splenopancreatectomy. The second patient was a 75-year-old man who complained of abdominal pain. An abdominal CT scan showed a cephalic pancreatic lesion and two hepatic metastases. An EUS-guided fine needle aspiration showed a pancreatic ACC. The patient received chemotherapy with gemcitabine plus oxaliplatin (GEMOX regimen), which enabled an objective response after 6 cycles.

Adenosquamous carcinoma of pancreas: CT and MR imaging features in eight patients, with pathologic correlations and comparison with adenocarcinoma of pancreas

PURPOSE

To reveal the CT and MR imaging features of adenosquamous carcinoma of pancreas (ASqC) in eight patients.

METHODS

This study was approved by our institutional review board. Eight patients with ASqC were included in this study. Radiologic and pathologic findings were reviewed in each lesion. Additionally, radiologic imaging findings were compared between ASqC and controlled adenocarcinoma groups.

RESULTS

Significant differences between ASqC and adenocarcinoma groups were noted in lesion shape, enhancement pattern on dynamic CT images, the presence or absence of necrosis, and tumor thrombus in the portal vein (PV) system. Compared with adenocarcinoma, ASqC tended to be round-lobulated shape (100% vs. 57.6%), have necrotic portions (100% vs. 39.4%), and have tumor thrombus in the PV system (37.5% vs. 6.1%). Extensive central necrosis was found in six (75%) of ASqC lesions. More lesions in ASqC group (62.5% vs. 12.1%) showed the highest absolute attenuation on pancreatic arterial phase (PAP) or portal venous phase (PVP) images, although the average attenuation values of all ASqC lesions on PAP, PVP, and delayed phase images were almost the same. Five (83.3%) of six resected lesions appeared as nodular type macroscopically. Microscopically, all lesions did not show infiltrating growth pattern, but showed an intermediate growth pattern, and were surrounded incompletely by fibrous tissue.

CONCLUSIONS

ASqC tended to be a round-lobulated lesion with extensive central necrosis. Additionally, tumor thrombus in the PV system was often present. These CT and MR imaging features could be a useful clue for diagnosing ASqC.

Role of magnetic resonance imaging in the detection and characterization of solid pancreatic nodules: An update

Pancreatic ductal adenocarcinoma is the most common malignant tumor of the pancreas. The remaining pancreatic tumors are a diverse group of pancreatic neoplasms that comprises cystic pancreatic neoplasms, endocrine tumors and other uncommon pancreatic tumors. Due to the excellent soft tissue contrast resolution, magnetic resonance imaging (MRI) is frequently able to readily separate cystic from noncystic tumors. Cystic tumors are often easy to diagnose with MRI; however, noncystic non-adenocarcinoma tumors may show a wide spectrum of imaging features, which can potentially mimic ductal adenocarcinoma. MRI is a reliable technique for the characterization of pancreatic lesions. The implementation of novel motion-resistant pulse sequences and respiratory gating techniques, as well as the recognized benefits of MR cholangiopancreatography, make MRI a very accurate examination for the evaluation of pancreatic masses. MRI has the distinctive ability of non-invasive assessment of the pancreatic ducts, pancreatic parenchyma, neighbouring soft tissues, and vascular network in one examination. MRI can identify different characteristics of various solid pancreatic lesions, potentially allowing the differentiation of adenocarcinoma from other benign and malignant entities. In this review we describe the MRI protocols and MRI characteristics of various solid pancreatic lesions. Recognition of these characteristics may establish the right diagnosis or at least narrow the differential diagnosis, thus avoiding unnecessary tests or procedures and permitting better management.

Clinics in diagnostic imaging (157). Acinar cell carcinoma (ACC) of the pancreatic tail

A 50-year-old Chinese man presented to the clinic with left hypochondrial pain, more than 10 kg of weight loss over a 3-month period, and a firm, large, ill-defined mass in the left upper quadrant. Contrast-enhanced computed tomography of the abdomen and pelvis revealed a well-circumscribed exophytic pancreatic mass with features suggestive of acinar cell carcinoma (ACC). The patient underwent chemotherapy and radiotherapy, with no evidence of local recurrence detected at one-year follow-up. He remains under close surveillance by his oncologist. Treatment for ACC includes surgical resection with adjuvant radiotherapy. Better overall survival is seen in patients with surgically resectable ACC as compared to those with the more common ductal cell carcinoma.

Pancreatic acinar cell carcinoma with bilateral ovarian metastases, panniculitis and polyarthritis treated with FOLFIRINOX chemotherapy regimen. A case report and review of the literature

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic tumor, with an estimated frequency of less than 1% of pancreatic malignancies. There are no prospective studies to guide diagnostic or therapeutic algorithms. We report the case of a 36 year-old woman, diagnosed of a pancreatic tumor with liver and peritoneal metastases that was initially managed as a neuroendocrine tumor with temozolomide and capecitabine. After two cycles a severely painful arthritis developed in her left ankle with panniculitis and extensive fat necrosis, and CT scan demonstrated progressive disease. Pathology of the primary was reassessed establishing the diagnosis of PACC. The patient started treatment with FOLFIRINOX regimen, achieving clinical benefit and disease stabilization. We also briefly reviewed the literature on this rare subtype of pancreatic tumor.

Imaging of pediatric pancreatic neoplasms with radiologic-histopathologic correlation

OBJECTIVE

The purpose of this article is to describe the imaging features of pediatric pancreatic tumors with pathologic correlation. Epithelial and nonepithelial lesions are described. Pancreatic imaging protocols, clinical presentation, and management are also detailed.

CONCLUSION

Pancreatic neoplasms are rare in children and vary widely between benign and malignant causes and between cystic and solid lesions. Epithelial tumors are most common and include solid pseudopapillary tumor, pancreatoblastoma, islet cell neoplasms, and cystic lesions.

CT imaging features of acinar cell carcinoma and its hepatic metastases

OBJECTIVE

To evaluate and describe the computed tomography features of pure acinar cell carcinoma (ACC) and its liver metastases.

METHODS

Thirty patients were evaluated. Two radiologists evaluated imaging findings for each tumor for size, location, internal density, enhancement, tumor calcifications, pancreatic, and common biliary ductal obstructions and metastases.

RESULTS

70 % were male. Fourteen tumors were located in the pancreatic head, 14 in the tail, one in the neck, and one in the uncinate process. Abdominal pain was the most common presenting symptom (93 %), 20 % had pancreatitis and 17 % had obstructive jaundice. The average tumor size was 7 cm, 97 % of tumors were solid, well circumscribed (73 %); isodense to normal pancreatic parenchyma (40 %) on the non-contrast study, hypodense on the arterial (47 %), and hypodense on the portal venous (37 %) phase. 30 % patients had pancreatic ductal dilation, 10 % had pancreatic ductal ingrowth, 6 % had calcifications, and 20 % had central necrosis, and 31 % (5/16) showed biliary ductal dilation. At presentation, 50 % had metastatic adenopathy and 40 % patients had liver metastases, which typically were well circumscribed, hypoattenuating to the hepatic parenchyma on all the phases of contrast enhancement and had a lobulated margin.

CONCLUSION

ACCs of the pancreas often present as large, well circumscribed, solid masses commonly in males. Despite their large size, they may not cause CBD obstruction.

Comparison of pancreatic acinar cell carcinoma and adenocarcinoma using multidetector-row computed tomography

AIM: To distinguish acinar cell carcinoma (ACC) from pancreatic adenocarcinoma (AC) by comparing their computed tomography findings.

METHODS: Patients with ACC and AC were identified on the basis of results obtained using surgically resected pancreatectomy specimens. The preoperative computer tomographic images of 6 acinar cell carcinoma patients and 67 pancreatic adenocarcinoma patients in 4 phases (non-contrast, arterial, portal venous, and delayed phase) were compared. The scan delay times were 40, 70, and 120 s for each contrast-enhanced phase. The visual pattern, tomographic attenuation value, and time attenuation curve were assessed and compared between AC and ACC cases using the χ² test, Wilcoxon signed-rank test, and Mann Whitney U test.

RESULTS: The adenocarcinomas tended to be hypodense in all 4 phases. The acinar cell carcinomas also tended to be hypodense in the 3 contrast-enhanced phases, although their computed tomographic attenuation values were higher. Further, 5 of the 6 acinar cell carcinomas (83%) were isodense in the non-contrast phase. The time attenuation curve of the adenocarcinomas showed a gradual increase through the 4 phases, and all adenocarcinomas showed peak enhancement during the delayed phase. The time attenuation curve of the acinar cell carcinomas showed peak enhancement during the portal venous phase in 4 cases and during the arterial phase in 2 cases. None of the 6 acinar cell carcinomas showed peak enhancement during the delayed phase.

CONCLUSION: The tumor density in the non-contrast phase and time attenuation curve pattern clearly differ between acinar cell carcinomas and adenocarcinomas, and multidetector-row computed tomography can thus distinguish these tumors.

Acinar cell carcinoma of the pancreas: computed tomography features--a study of 15 patients

OBJECTIVE

Evaluation of the imaging features of pathology-proven acinar cell carcinomas (ACCs) of the pancreas using computed tomography (CT).

METHODS

We reviewed the CT features, clinical presentations, and clinical outcomes of 15 patients (9 men, 6 women, mean age 62.3) with pathology-proven pancreatic ACCs. An abdominal radiologist retrospectively evaluated each patient's initial imaging study with respect to the lesion's size, location, attenuation (Hounsfield units) on arterial and venous phase images, peripancreatic lymphadenopathy, and distant metastases. Additional parameters studied included biliary and pancreatic ductal dilatation, intratumoral hemorrhage, calcification, the presence of cystic/necrotic components, and whether the tumor was intraparenchymal or exophytic.

RESULTS

The ACCs in this series were evenly distributed between the head/uncinate and the tail, were predominantly exophytic (73%), tended to be large (average size 5.1 cm), and were mostly hypodense to the surrounding pancreas on both the arterial and venous phase images. A sizeable proportion demonstrated a cystic or necrotic component (53%) and/or an enhancing capsule (53%). Of those lesions in the head or uncinate process, very few resulted in pancreatic (28%) or biliary (14%) ductal dilatation. None of the lesions in this series showed internal calcification or intratumoral hemorrhage.

CONCLUSION

While a prospective diagnosis is difficult, ACCs have several features which can differentiate them from ductal adenocarcinoma, including their large size, lack of biliary or pancreatic ductal dilatation, exophytic nature, and the presence of an enhancing capsule.

Adenosquamous carcinoma of the pancreas: multidetector-row computed tomographic manifestations and tumor characteristics

OBJECTIVE

The purpose of this article was to present the adenosquamous carcinoma (ASqC) of the pancreas: multidetector-row computed tomographic (CT) features and tumor characteristics.

MATERIALS AND METHODS

The clinical data and CT studies of 12 patients with pathologically proven ASqC of the pancreas between the dates February 2001 and February 2010 were retrospectively analyzed.

RESULTS

The presenting symptoms of ASqC of the pancreas were nonspecific. Elevated serum levels of carbohydrate antigen 19-9, carbohydrate antigen 12-5, and carcinoembryonic antigen were noted. The tumor was most commonly involved in the pancreatic head in 6 patients, with the dilation of the common bile duct and the upstream main pancreatic duct. All ASqCs exhibited invasive growth. No calcification and intratumoral hemorrhage were noted in ASqCs. Ten tumors showed enhancement in the early arterial phase and persistent enhancement in the portal vein phase.

CONCLUSION

The typical CT appearance of ASqC was solitary oval or round without any capsule and a defined margin. The dilation of the main pancreatic duct and/or the common bile duct was always discovered. The huge infiltrative lesion outside the pancreas was detected in the tail and/or the body of the pancreas. Not only the elevation of carbohydrate antigen 19-9 is common, but also Ca12-5 and CEA, whereas human alpha fetoprotein elevation is not observed. The enhancement pattern of tumor showed persistence in the portal vein phase.

Clinical and CT imaging features of pancreatic acinar cell carcinoma

PURPOSE

This study was undertaken to analyse the clinical characteristics and computed tomography (CT) imaging features of patients with pancreatic acinar cell carcinoma and to clarify characteristic imaging features.

MATERIALS AND METHODS

Clinical and CT imaging records of ten patients with pancreatic acinar cell carcinoma (three women and seven men; mean age, 58 years) examined using multidetector CT scanners were retrospectively studied. CT features emphasised included lesion location, size, shape, margin, solid or cystic component, density and enhancement. Imaging results were correlated with intraoperative surgical and pathological results.

RESULTS

Lesions were distributed throughout the pancreatic head (n=3), body (n=3), tail (n=2) and both body and tail (n=2). The average diameter was 6.1 cm, varying from 2.3 cm to 15.8 cm. The tumours were round or oval (n=7) or lobular (n=3). Seven tumours appeared as enhanced solid pancreatic masses, with the large masses having hypodense areas; three had >75 % cystic component; seven (70%), including four solid and three cystic masses, had well-circumscribed or partially well-defined thin, enhanced encapsulation. After contrast injection, the masses presented heterogeneous enhancement.

CONCLUSIONS

Acinar cell carcinoma should always be considered when a large pancreatic mass with typical imaging is found in solid masses with variably sized central cystic areas or cystic masses.

Clinicopathologic study of 62 acinar cell carcinomas of the pancreas: insights into the morphology and immunophenotype and search for prognostic markers

Acinar cell carcinoma (ACC) of the pancreas is a very rare tumor that has various morphologic features, which may give rise to diagnostic difficulties. Because of its rarity, many clinicopathologic characteristics remain to be further elucidated, and prognostic factors are yet to be well established. With the aim of better characterizing this carcinoma and searching for prognostic indicators, we collected 62 ACCs and investigated the following parameters: site, size, local infiltration, node and distant metastases, architectural pattern, nuclear atypia, presence of necrosis, lymphovascular and perineural invasion, proliferation, BCL10, trypsin, carboxyl ester lipase, amylase, lipase, PDX1, cytokeratin 19 (CK19), CK7, p53, and β-catenin expression. Twelve cases showing >30% of endocrine cells were reclassified as mixed acinar-neuroendocrine carcinomas, whereas 1 tumor was reclassified as a mixed ductal-acinar carcinoma and was excluded from the statistical prognostic evaluations. BCL10 and trypsin were the most reliable immunohistochemical markers, whereas amylase and lipase were not. Surgery was statistically correlated with a better prognosis (P=0.0008). Among resected tumors there was no difference in survival between ACCs and mixed acinar-neuroendocrine carcinomas, and factors that significantly correlated with poor prognosis were size >6.5 cm (P=0.004), lymph node (P=0.0039) and distant (P=0.008) metastases, and UICC stage (P=0.009). Stage was the only independent prognostic factor at multivariable analysis, and the best prognostic discrimination was observed on grouping together stages I and II and grouping together stages III and IV, suggesting a simplification of the UICC staging for such cancers. In addition, vascular and perineural invasion and CK19 and p53 expression showed a trend for poor prognosis, not reaching statistical significance.

The CT findings of pancreatic acinar cell carcinoma in five cases

OBJECTIVES

The aim of this study is to analyze the computed tomographic (CT) findings of pancreatic acinar cell carcinoma (ACC).

MATERIALS AND METHODS

The CT features and clinical presentations of five patients (four men, one woman; mean age, 52 years) with pathology-proven pancreatic ACC were reviewed. The image characteristics included the lesion location and size, the exophytic nature of the tumor, intratumoral hemorrhage, calcification, the presence of cystic or necrotic components, bile or pancreatic duct dilation, attenuation on the noncontrast image, attenuation on the arterial- and venous-phase images, peripancreatic invasion, peripancreatic lymphadenopathy, and distant metastases.

RESULTS

The tumors were located at the pancreatic tail in three cases and at the pancreatic head in two cases. The average lesion size was 5.3 cm. Exophytic features and cystic/necrotic components were found in 80% (4/5) and 60% (3/5) of cases, respectively. The ACC showed a mild hypodense appearance on noncontrast CT in 100% (3/3) of cases and a hypodense appearance on arterial-/venous-phase CT in 80% (4/5) of cases. The exception was one lesion that showed a significantly hyperdense appearance and a mildly hyperdense appearance on the arterial- and venous-phase images. None of the CT images showed enhancement of a capsule, calcification, intratumoral hemorrhage, bile or pancreatic duct dilation, vascular encasement, or distant metastatic disease, but three cases showed peripancreatic invasion and lymphadenopathy.

CONCLUSIONS

With persistent mild enhancement, the typical ACC appears as an exophytic tumor with a focal cystic/necrotic component and the lack of ductal dilatation. The predilection for older male patients and elevated serum alpha fetoprotein are useful clinical features for confirming an ACC diagnosis.

Acinar cell carcinoma of the pancreas: a rare tumor with a particular clinical and paraclinical presentation

Acinar cell carcinoma (ACC) of the pancreas is a rare tumor with an extremely low incidence rate. While the number of reported patients with ACC is relatively small, a long-term survival rate has been noted in patients with neuroendocrine differentiation. A 39-year-old woman visited our emergency department for upper gastrointestinal bleeding. Endoscopy indicated extrinsic compression of the posterior body of the stomach, together with a large, 10-cm, central ulcer covered with necrotic tissue. Abdominal computed tomography (CT) indicated a lesion that involved the whole of the pancreas, with a fistula in the stomach, which was suspected of being a degenerative intraductal papillary mucinous tumor of the pancreas. Magnetic resonance imaging (MRI) of the pancreas was performed, and the results further strengthened our suspicions by demonstrating the presence of cystic lesions and tumor buds. A total duodenopancreatectomy, including total splenectomy and gastrectomy, was performed, along with two independent Roux-en-Y anastomoses (one esojejunal and one hepaticojejunal). The tumor also had a wide opening in the stomach. The patient's postoperative course was marked by partial thrombosis of the portal vein, which was treated medically. Histopathological examination provided evidence of pancreatic ACC. The diagnosis of ACC should be considered in the presence of cutaneous lesions, which were absent in the case of our patient, and colonoscopy is also highly desirable because of the various forms associated with familial adenomatous polyposis. The prognosis, which includes a 5-year survival rate of 45%, in the population with an R0 resection is better than that for ductular adenocarcinoma, thus prompting the more aggressive management of this type of tumor.

Acinar cell carcinoma of the pancreas: is resection justified even in limited metastatic disease?

BACKGROUND

Acinar cell carcinoma (ACC) of the pancreas is characterized by better long-term survival compared with the more common ductal adenocarcinoma, and prognosis is better in resected compared with nonresected patients. The aim of the present study was to investigate the role of surgery in ACC with limited metastatic disease.

METHODS

All patients with histologically confirmed ACC treated at the investigators' institution between October 2001 and September 2009 were identified from a prospective database. Clinicopathologic details, perioperative results, and follow-up results were analyzed.

RESULTS

Seventeen patients with nonmetastatic and metastatic ACC were identified. Initially, localized, locoregional, and metastatic disease was present in 5, 7, and 5 patients, respectively. Pancreatic resections were performed in 15 patients. In limited metastatic disease, additional liver resection was performed in 3 patients and omentectomy in 1 patient. In 2 patients, metachronous liver metastases were resected. With a median follow-up period of 36.5 months, overall 1-year, 2-year, and 3-year survival rates were 88%, 65%, and 47%, respectively. Survival of resected patients with metastatic and nonmetastatic disease showed no differences between the 2 groups.

CONCLUSIONS

ACC of the pancreas is a relatively rare tumor entity for which resection may result in long-term survival even in limited metastatic disease.

Acinar cell cystadenoma (acinar cystic transformation) of the pancreas: the radiologic-pathologic features

Acinar cystic transformation of the pancreas is also known as acinar cell cystadenoma (ACC), and this is an extremely rare benign lesion that was first described in April 2002. We report here on a case of a previously asymptomatic patient with pancreatic ACC and this was diagnosed by computed tomography (CT) and magnetic resonance imaging (MRI). To the best of our knowledge, there is no previous report concerning the CT or MRI features of ACC in the medical literature. We present here the CT, MRI and pathological findings of pancreatic ACC.

Aggressive approach to acinar cell carcinoma of the pancreas: a single-institution experience and a literature review

PURPOSE

Acinar cell carcinomas (ACCs) are a rare pancreatic tumor group with no standardized treatment. The aim of the study is to analyze the clinical and pathologic characteristics of our series and to review the current literature.

METHODS

Retrospective review of prospectively collected data from 1990 to 2007 included patients who underwent pancreatic resection for histologically proven ACCs. All specimens of ACC were rereviewed by an expert pathologist. Follow-up was updated to October 2009. A literature search was performed by Pubmed and COCHRANE library.

RESULTS

Among 1,210 patients who underwent pancreatic resection, we identified nine ACCs. R0 resection was possible for all but one R1. We had no major complications and no mortality. All nine cases were diagnosed as pure ACCs. Five patients received adjuvant chemotherapy. Median overall survival was 31 months, while median disease-free survival was 18 months. All patients developed liver metastases, requiring modification of chemotherapeutic schema, radiofrequency ablation techniques, or reiterate surgery. Currently, only one patient is alive without evidence of disease 85 months after pancreatic resection. One patient is alive 52 months after operation, with evidence of recurrent disease.

CONCLUSIONS

ACC represents a rare solid tumor of the pancreas. Prognosis is dismal, although, compared to the more common ductal adenocarcinoma, survival appears to be longer. Patients with metastatic disease might benefit from aggressive multimodality treatments.

Long-term survival after a repetitive surgical approach in a patient with acinar cell carcinoma of the pancreas and recurrent liver metastases: report of a case

Acinar cell carcinoma is a relatively rare malignant neoplasm, which represents 1%-2% of all pancreatic exocrine tumors. Its prognosis is thought to be poor, especially when it metastasizes to the liver. This report concerns a case of a long-term survivor of metastatic acinar cell carcinoma who was successfully treated with repetitive surgery. A 62-year-old man underwent a distal pancreatectomy for a pancreatic tumor, which was histologically diagnosed as an acinar cell carcinoma. The tumor recurred in the liver three times within 41 months. At the first recurrence, four hepatic lesions appeared 7 months after the initial pancreatectomy and were managed with an extended left hepatic lobectomy and partial liver resection. Thereafter, a solitary nodule in Segment 6 was identified 21 months after the second surgery and was treated with a partial liver resection. A solitary lesion in Segment 8/5 appeared 11 months after the third surgery and was also managed by a partial liver resection. The patient has remained disease-free for 22 months since the last surgery and has survived 65 months since the initial diagnosis. Although no consensus has been reached on surgery for metastatic acinar cell carcinoma, the current case has important implications for establishing an appropriate treatment strategy.

CT and MRI features of acinar cell carcinoma of the pancreas with pathological correlations

AIM

To document the computed tomography (CT) and magnetic resonance imaging (MRI) features of acinar cell carcinoma of the pancreas and to correlate them with pathological findings to determine the unique imaging manifestations of this rare subtype tumour of the pancreas.

MATERIALS AND METHODS

From January 1986 to August 2008, six patients (five men and one woman, mean age 61.3 years) with histologically proven acinar cell carcinoma of the pancreas underwent CT (n=6) and MRI (n=4) examinations. The imaging features of each tumour were documented and compared with pathological findings.

RESULTS

The tumours were distributed in the head (n=4), body (n=1), and tail (n=1) of the pancreas. Four masses (67%) were uniformly or partially well-defined with thin, enhancing capsules. Central cystic components were found in five tumours (83%). Two tumours (33%) exhibited intratumoural haemorrhage, and one tumour (17%) had amorphous intratumoural calcification. In both CT and MRI, the tumours enhanced less than the adjacent normal pancreatic parenchyma. The signal intensity on MRI was predominantly T1 hypointense and T2 iso- to hyperintense.

CONCLUSION

Acinar cell carcinoma of the pancreas has distinct imaging features, and both CT and MRI are useful and complementary imaging methods.