Case report: primary acinar cell carcinoma of the liver treated with multimodality therapy

Recent Advances in Pathology of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICCA) is a malignant epithelial neoplasm characterized by biliary differentiation within the liver. ICCA is molecularly heterogeneous and exhibits a broad spectrum of histopathological features. It is a highly aggressive carcinoma with high mortality and poor survival rates. ICCAs are classified into two main subtypes: the small-duct type and large-duct types. These two tumor types have different cell origins and clinicopathological features. ICCAs are characterized by numerous molecular alterations, including mutations in KRAS, TP53, IDH1/2, ARID1A, BAP1, BRAF, SAMD4, and EGFR, and FGFR2 fusion. Two main molecular subtypes-inflammation and proliferation-have been proposed. Recent advances in high-throughput assays using next-generation sequencing have improved our understanding of ICCA pathogenesis and molecular genetics. The diagnosis of ICCA poses a significant challenge for pathologists because of its varied morphologies and phenotypes. Accurate diagnosis of ICCA is essential for effective patient management and prognostic determination. This article provides an updated overview of ICCA pathology, focusing particularly on molecular features, histological subtypes, and diagnostic approaches.

Optimizing Chemotherapy of Pancreatic Acinar Cell Carcinoma: Our Experiences and Pooled Analysis of Literature

Background:

Pancreatic acinar cell carcinoma (PACC) is rare, and its appropriate treatment remains unknown. We aim to explore the characteristics and optimal treatment of it.

Methods:

The data on clinicopathologic characteristics, molecular alteration, treatment, and survival of patients diagnosed with PACC at the Sun Yat-sen University Cancer Center from 2005 to 2020 were collected. The optimal treatment was explored by co-analyzing our results and published literatures.

Results:

Twenty-two PACC patients were enrolled. Eight of 17 non-metastatic patients received adjuvant chemotherapy. The patients receiving fluoropyrimidine-based regimen (n = 3) had a better median disease-free survival (mDFS) than those with gemcitabine-based regimen (n = 5) (unreached vs 27 months). Eight metastatic patients received first-line chemotherapy. Four patients received second-line chemotherapy. The objective response rate (ORR) of the fluoropyrimidine-based regimen was 85.7% (6/7), much better than that of the gemcitabine-based regimen (0/5). One patient who had responded to the first-line FOLFIRINOX (5-fluorouracil + oxaliplatin + leucovorin + irinotecan) regimen received olaparib as maintenance treatment for 5 months with good tolerance. Thirty-one published literatures, with a total of 86 cases, were included in the co-analysis. The ORR of the first-line fluoropyrimidine-based regimen (n = 47) was higher than that of gemcitabine-based regimen (n = 39) (59.6% vs 15.3%, P < .001). Eight of 11 patients treated with the FOLFIRINOX regimen achieved partial response (PR).

Conclusions:

For patients with metastasis, a fluorouracil-based regimen such as FOLFIRINOX may be preferred, and maintenance treatment of poly ADP-ribose polymerase (PARP) inhibitors after effective platinum-containing treatment for breast cancer susceptibility gene (BRCA) mutation patients must be assessed.

An unusual case of primary acinar cell carcinoma of the liver and its treatment

Acinar cell carcinoma (ACC) is an epithelial neoplasm characterized by morphological features similar to acinar cells found in exocrine glands. Most cases of hepatic ACC reveal evidence of pancreatic exocrine enzyme production and are considered to be metastatic from the pancreas. However, a small number of hepatic ACC cases have been reported in which the tumor is believed to have originated in the liver rather than being a metastatic lesion. In this report we present a case of primary ACC of the liver. A 59-year-old female with no significant past medical history presented with the chief complaint of abdominal pain. A computed tomography (CT) scan of the abdomen showed innumerable mass lesions throughout the liver, initially concerning for metastatic disease. Histopathologic morphology was most consistent with that of ACC, possibly of pancreatic origin. However, the CA 19-9 level was not elevated and no pancreatic lesions were detected on the CT scan. Similar to a previously reported case, the diagnosis of primary ACC of the liver was made based on: acinar cells seen on histology, findings on immunohistochemical staining, radiographic images of liver masses, and the absence of extrahepatic lesions. Previous case reports of primary ACC have differing hypotheses regarding this rare finding. One hypothesis suggests an ectopic origin of acinar cells within the liver. An alternative hypothesis proposes that hepatic and pancreatic cells are ontogenetically derived from a common progenitor cell, which is thought to result in hepatic cells differentiating into acinar cells. The patient was treated with gemcitabine and paclitaxel every 2 weeks for 8 months and then transitioned to every 3 weeks for better tolerance. The patient's symptoms significantly improved within the first 6 weeks of treatment. At the time of the preparation of this report, it has been 17 months since initiation of therapy, and follow-up imaging continues to demonstrate a dramatic decrease in both size and number of hepatic nodules. ACC's are rare tumors that are usually found in glandular tissues. Primary ACC of the liver is extremely rare with only a few cases having been reported. This article adds to the limited literature available on primary hepatic ACC.

Cytopathology and ultrastructure identification of primary hepatic acinar cell carcinoma: Case report

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Acinar cell carcinoma originating in the liver proper remains a diagnostic quandary.

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Non-specific imaging features may have led to prior misdiagnosis and poor outcomes.

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Ultrastructural electron microscopy represents a novel tool for identification.

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Heterotopia or metaplastic mechanisms may underlie hepatic acinar cell localization.

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The previous literature is summarized in context of the present case of hepatic ACC.

Introduction

A primary acinar cell carcinoma (ACC) of the liver was incidentally diagnosed in a clinically asymptomatic 80-year-old man. This study aimed to delineate critical diagnostic characteristics of an ACC originating uniquely from the liver to improve its future identification.

Presentation of case

Enhanced MRI revealed a heterogenous, cystic 7.7 × 11.1 × 10.4 cm tumour occupying hepatic segments II and III. The mass demonstrated mild diffuse enhancement in hepatic arterial phase with minimal portal venous washout in a liver without cirrhotic features. A central stellate T2-hyperintense necrotic scar and outer capsule were apparent. No primary lesion or metastasis outside the liver was discernable. Post-left hepatic lobectomy, the tumour immunophenotype was atypical for presumptive diagnoses of hepatocellular carcinoma (HCC) or cholangiocarcinoma. Extensive morphologic workup on electron microscopy definitively diagnosed primary hepatic ACC by establishing presence of secretory zymogen-like granules, intracytoplasmic microvilli and acinar cell differentiation. Cytopathology revealed cellular lumen expressing PAS-positive diastase-resistant granular cytoplasmic contents.

Discussion

This case showcased the novel utility of electron microscopy that was crucial in yielding the definitive diagnosis. The previous literature on hepatic ACC was compiled here in context of the present case. The mechanism of hepatic acinar cell localization was also discussed.

Conclusion

Primary hepatic ACC may easily be confused for other lesions due to nonspecific imaging patterns. Specifically, the presence of a central scar without risk factors for HCC can favour a diagnosis of benign entities such as focal nodular hyperplasia (FNH). Electron microscopy presents an important tool to identify primary hepatic ACC and may improve future patient outcomes.