Acinar cell carcinoma of the pancreas: clinical analysis of 115 patients from Pancreatic Cancer Registry of Japan Pancreas Society

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.

An effective personalized approach to a rare tumor: prolonged survival in metastatic pancreatic acinar cell carcinoma based on genetic analysis and cell line development

Acinar cell carcinoma of the pancreas is an uncommon malignancy, accounting for less than 1% of all pancreatic neoplasms. Because of its rarity, only a few retrospective studies are available to help guide management. We report the case of a patient with metastatic ACC who achieved prolonged survival as a result of personalized treatment designed in part on the basis of molecular and in-vitro data collected on analysis of the tumor and a cell line developed from the liver metastasis. To our knowledge, this represents the first human cell line of ACC. The molecular findings on this case and this patient's cell line may be of use in the management of future cases of this rare tumor and allow the identification of potential novel targets for the effective treatment of this disease.

A case of pancreatic acinar cell carcinoma metastatic to skin

We report a rare case of pancreatic acinar cell carcinoma with widespread metastases in a 68-year-old woman who presented with subcutaneous nodules as the initial symptom. Computed tomography showed a pancreatic mass with hepatic tumors and enlarged lymph nodes besides ring-enhanced subcutaneous nodules. Magnetic resonance diffusionweighted imaging detected the presence of lesions in other organs. Histological analysis of a colonic polypoid lesion revealed carcinoma with endocrine and acinar differentiation compatible with pancreatic origin. Regrettably, she died of a cerebral infarction without any treatment, and autopsy findings confirmed our diagnosis.

Diagnostic approach to pancreatic tumors with the specimens of endoscopic ultrasound-guided fine needle aspiration

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has enabled clinicians to histologically diagnose pancreatic tumors. However, EUS-FNA specimens often result in tiny fragmented tissues, so auxiliary utilities are necessary. Using immunostaining of CK7, CDX2, neuroendocrine markers and KRAS mutation analysis, we examined 57 FNA cell block sections and 61 surgically-resected specimens (25 invasive ductal carcinomas, 25 endocrine tumors, and 11 acinar cell tumors). In the majority of the matched pairs, the diagnoses between EUS-FNA and surgical specimens were concordant using the following criteria: neuroendocrine markers negative, CK7 positive, and mutated KRAS gene for invasive ductal carcinomas; neuroendocrine markers diffusely positive, CK7 and CDX2 negative, and wild-type KRAS gene for well-differentiated endocrine tumors; and neuroendocrine markers no more than focal positive, CK7 and CDX2 with various staining patterns, and wild-type KRAS gene for acinar cell carcinomas. Expression of CK7 and/or CDX2 in addition to KRAS mutations were occasionally seen in endocrine carcinomas, but not in well-differentiated endocrine tumors, suggesting that ductal differentiation in an endocrine tumor may be a predictor of aggressive disease. The usefulness of these markers was confirmed using 13 additional pancreatic tumors, prospectively. Although minimal in selection, these markers are helpful in making diagnosis from EUS-FNA specimens of the major pancreatic tumors.

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.

[Acinar cell carcinoma of the pancreas in Korea--clinicopathologic analysis of 27 patients from korean literature and 2 cases from our hospital--]

BACKGROUND/AIMS

Acinar cell carcinoma (ACC) of the pancreas is a rare malignancy. ACC has been considered a cancer with poor prognosis due to frequent metastasis, a high recurrence rate, and low resectability. The aim of this study was to examine the clinical, radiologic and pathologic features of ACC in Korean patients, and surgical outcome was also investigated.

METHODS

We reviewed the clinical records of two patients with ACC who had undergone operation in January 1996 and December 2005 at Hanyang University Medical Center. Through searching of medical journal from 1983 to 2009, 27 patients reported on literatures as Korean ACC patients were reviewed together. The clinical, pathohistologic, and radiologic features, treatment, and prognosis were investigated for all 29 patients.

RESULTS

ACC was more common in male, and age at diagnosis ranged from 25 to 68 years (median 54). Symptoms were, mostly abdominal pain and mass. Liver was most common organ of metastasis at diagnosis and recurrence after operation. The mean tumor size was 7.0 cm, and most common location was tail. Of the 29 patients, 22 underwent surgical resection. Excluding 7 cases of not-reported survival, the median survival with operation was 22.4 months compared to 1.5 months with non-operation.

CONCLUSIONS

In Korea, the clinical features of ACC include young age, large size, tail location, and nonspecific tumor markers. Surgery should be actively performed in the treatment of ACC regardless of size.

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.

Pancreatic acinar cell carcinomas with prominent ductal differentiation: Mixed acinar ductal carcinoma and mixed acinar endocrine ductal carcinoma

BACKGROUND

Pancreatic acinar cell carcinomas (ACCs) are clinically and pathologically distinct from pancreatic ductal adenocarcinomas (PDAs). Whereas endocrine differentiation has been well shown in ACCs, significant ductal components are rare. This paper reviews the clinicopathologic features of a series of ACCs with prominent ductal differentiation.

DESIGN

Cases of pancreatic ACCs with significant ductal differentiation were identified in the surgical pathology databases of 2 academic centers. Patient clinical information, gross and histologic features, and histochemical and immunohistochemical (IHC) results were recorded. Cases were tested for KRAS2 mutations.

RESULTS

Eleven cases were identified (10 men and 1 woman; age range 52 to 79 y). Four patients presented with jaundice. At last follow-up, 7 patients died of disease and 2 others had recurrences. Tumors measured between 2 and 5.5 cm and were ill-defined, nodular, and multilobulated. Ten were located in the head of the pancreas. All but 2 exhibited extrapancreatic invasion. All cases showed significant evidence of both acinar and ductal differentiation, estimated to be at least 25% of the neoplastic cells, and 3 cases in addition had endocrine differentiation in more than 25% of cells. Five cases were predominately acinar with intracellular and sometimes extracellular mucin ("mucinous acinar cell carcinoma" pattern). Six cases seemed more mixed with areas recapitulating typical PDAs whereas the other portions of the tumors seemed akin to typical acinar cell carcinomas ("combined acinar and ductal" pattern). IHC positive staining results were as: trypsin (92%), chymotrypsin (92%), monoclonal carcinoembryonic antigen (100%), CK19 (100%), B72.3 (73%), CA19.9 (73%), CD56 (18%), synaptophysin (36%), and chromogranin (36%). One case showed p53 over-expression aznd none showed DPC4/Smad4 loss. Two cases had KRAS2 mutations.

CONCLUSION

Despite the early embryologic divergence of acinar and ductal cell lineages, rare pancreatic tumors have both acinar and ductal differentiation, usually predominantly the former. The clinical course is highly aggressive.

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.

Pancreatic acinar cell carcinoma: a multi-institutional study

INTRODUCTION

The presentation and outcome of patients with acinar cell carcinoma (ACC) of the pancreas compared to the more common ductal cell adenocarcinoma (DCA) may be distinct. This study combines the experience with ACC from multiple academic institutions to better understand its natural history and outcomes.

METHODS

This study is a multi-institutional retrospective review of patients with ACC.

RESULTS

Between 1988 and 2008, 17 patients were identified with pathologically confirmed ACC. Median age at presentation was 59 years. Common presenting symptoms were abdominal pain (60%), back pain (50%), and weight loss (45%). Fifteen patients underwent 16 operations: pancreaticoduodenectomy (nine), distal pancreatectomy (four), and exploratory laparotomy (three). Mean tumor size was 5.3 cm. American Joint Commission on Cancer tumor stages were stage I (two), stage II (eight), stage III (four), and stage IV (three). Overall, 1- and 5-year survival rates were 88% and 50%, respectively. In resected cases (13), 1- and 5-year survival rates were 92% and 53%, respectively. Median survival in resected cases was 61 months. This is in contrast to 1,608 patients with ductal cell adenocarcinoma who underwent resection identified from recent literature reports where the average median survival was only 24 months. There was no discernable difference in the outcomes of patients with ACC between United States and Germany patients.

CONCLUSION

Acinar cell carcinoma of the pancreas is rare and appears to have a presentation and outcome distinct from the more common pancreatic DCA. Based upon these data, the outcome of patients with ACC is superior to that of DCA.

Molecular classification of neoplasms of the pancreas

The recent sequencing of the pancreatic cancer genome provides unprecedented insight into the fundamental nature of this deadly malignancy. Although much work still needs to be done, a molecular classification of neoplasms of the pancreas is emerging. Molecular genetics have been used to identify unique clinical subtypes of pancreatic cancer, to guide the clinical diagnosis of pancreatic tumors, and to identify targeted therapies for select pancreatic neoplasms. This review examines the emerging molecular classification of neoplasms of the pancreas. This classification does not ignore previous histology-based classification systems but instead embraces them, creating an integrated histological-molecular classification.

Curative resection of a primarily unresectable acinar cell carcinoma of the pancreas after chemotherapy

Background

Acinar cell carcinoma (ACC) represents only 1–2% of pancreatic cancers and is a very rare malignancy. At the time of diagnosis only 50% of the tumors appear to be resectable. Reliable data for an effective adjuvant or neoadjuvant treatment are not available.

Case presentation

A 65-year old male presented with obstructive jaundice and non-specific upper abdominal pain. MRI-imaging showed a tumor within the head of the pancreas concomitant with Serum-Lipase and CA19-9. During ERCP, a stent was placed. Endosonographic fine needle biopsy confirmed an acinar cell carcinoma. Laparotomy presented an locally advanced tumor with venous infiltration that was consequently deemed unresectable. The patient was treated with five cycles of 5-FU monotherapy with palliative intention. Chemotherapy was well tolerated, and no severe complications were observed. Twelve months later, the patient was in stable condition, and CT-scanning showed an obvious reduction in the size of the tumor. During further operative exploration, a PPPD with resection of the portal vein was performed. Histopathological examination gave evidence of a diffuse necrotic ACC-tumor, all resection margins were found to be negative. Eighteen months later, the patient showed no signs of recurrent disease.

Conclusion

ACC responded well to 5-FU monochemotherapy. Therefore, neoadjuvant chemotherapy could be an option to reduce a primarily unresectable ACC to a point where curative resection can be achieved.

Acinar cell carcinoma of the pancreas in the United States: prognostic factors and comparison to ductal adenocarcinoma

INTRODUCTION

Pancreatic acinar cell carcinoma (ACC) is a rare tumor with poorly defined prognosis.

OBJECTIVE

Our objective was to compare a large population of patients with ACC to pancreatic ductal cell adenocarcinoma (DCC) in order to determine distinguishing characteristics and to assess survival.

METHODS

Patients were identified from the National Cancer Database. Regression methods were used to identify differences between ACC and DCC and to identify predictors of survival for resected ACC. Eight hundred sixty-five patients with ACC were identified.

RESULTS

Median tumor size was 6.9 cm (vs. 4.6 cm DCC); 32.1% had nodal metastases (vs. 48.0% DCC); and 47% had high-grade tumors (vs. 37.3% DCC). Resection margins were R0 77.3%, R1 13.7%, and R2 9.0%. Patients with ACC were more likely to be male, white, and have larger tumor size, no nodal involvement, or pancreatic tail tumors. Stage-specific 5-year survival was significantly better for resected ACC vs. DCC Stage I: 52.4% vs. 28.4%, II: 40.2% vs. 9.8%, III: 22.8% vs. 6.8%, and IV: 17.2% vs. 2.8%. On multivariable analysis, age < 65, well-differentiated tumors, and negative resection margins were independent prognostic factors for ACC.

DISCUSSION

ACC carries a better prognosis than DCC. Aggressive surgical resection with negative margins is associated with long-term survival in these more favorable pancreatic cancers.

Primary acinar cell carcinoma of the liver

We report a case of acinar cell carcinoma primary to the liver. The tumor was diagnosed in a 35-year-old woman complaining of abdominal pain and asthenia; serum alpha-fetoprotein (AFP) levels were increased at 6,000 IU/mL; imaging studies showed a hypervascular mass located in the left lobe of the liver. A left lobectomy was performed. The tumor had a heterogeneous appearance. In well-differentiated areas, tumor cells formed acinar structures, had a pyramidal shape and a highly eosinophilic, granular cytoplasm, PAS diastase resistant. In less-differentiated areas, tumor cells were endocrinelike. The immunohistochemical study showed that tumor cells expressed trypsin. Alpha-fetoprotein and alphal-antritrypsin were detected in about 30% of cells; HepPar1 was present in 15% of cells. Chromogranin A and synaptophysin were detected in rare cells. After surgery, serum AFP levels quickly returned to normal; no evidence of recurrence or metastasis was observed during follow-up. The final diagnosis, based on histological, immunohistochemical, and ultrastructural arguments, was extra-pancreatic acinar cell carcinoma, primary to the liver. This unusual lesion is likely to be the result of an abnormal differentiation pathway involving a transformed multipotential progenitor cell.

672 patients with acinar cell carcinoma of the pancreas: a population-based comparison to pancreatic adenocarcinoma

BACKGROUND

Acinar cell carcinoma (ACC) is a rare cancer of the pancreas accounting for approximately 1% of nonendocrine tumors. Because no large series of patients with ACC exist, our understanding of this disease comes mainly from small retrospective reports and anecdotal experience.

OBJECTIVE

Our goal was to evaluate a large population-based cohort of patients with ACC and compare their demographic factors and outcomes to those of patients with pancreatic adenocarcinoma (PA).

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) database (1988 to 2003), we identified all patients with ACC or PA. The demographic factors, tumor characteristics, resection status, and long-term survival were compared between the 2 groups.

RESULTS

A total of 672 patients with ACC and 58,526 with PA were identified. The mean age at the time of diagnosis was significantly lower for ACC than PA (56 years vs 70 years, P < .001). Compared with patients with PA, patients with ACC were more likely to be male (54% vs 48%, P = .007) and white (85% vs 81%, P = .03). Based on SEER clinical staging, patients with ACC were less likely to have unstaged disease (8% vs 18%). Of the 616 patients with staged ACC, 16% had localized disease, 26% had regional disease, and 58% had distant disease. In the 47,896 staged patients with PA, 10% had localized disease, 33% had regional disease, and 57% had distant disease (P < .0001 compared to ACC). Based on clinical extent of disease, 81% of patients with locoregional ACC and 70% of patients with locoregional PA were resectable. However, only 69% of ACC patients with locoregional disease and 27% of PA patients with locoregional disease underwent surgical resection. The overall 5-year survival was 42.8% for ACC (median, 47 months) and 3.8% for PA (median, 4 months, P < .0001). Patients with unresected ACC had a 5-year survival rate of 22% compared to 2% in patients with unresected PA (P < .0001). Surgical resection significantly improved survival. The 5-year survival was 72% in resected ACC and 16.3% in resected PA (P < .0001). Multivariate Cox proportional hazards regression model results suggested patients with ACC were less likely to die (hazard ratio = 0.241; 95% confidence interval, 0.22-0.27) than patients with PA after controlling for gender, race, stage, SEER region of diagnosis, and surgical resection status.

CONCLUSIONS

Consistent with anecdotal reports and previous retrospective studies, ACC is a more indolent disease than PA. Patients with ACC tend to present at a younger age, are more likely to have resectable disease, and are much more likely to undergo potentially curative resection. The long-term survival for patients with ACC is significantly better when compared to the long-term survival of patients with PA.