Evidence for hepatocellular differentiation in alpha-fetoprotein-negative gastric adenocarcinoma with hepatoid morphology: a study with in situ hybridisation for albumin mRNA

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

Single-cell characteristics and malignancy regulation of alpha-fetoprotein-producing gastric cancer

OBJECTIVE

To characterize alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC) at the single-cell level and to identify regulatory factors for AFP expression and malignancy.

METHODS

ScRNA-seq was performed on two tumors collected from patients with AFPGC. InferCNV and sub-clustering were applied to identify typical AFPGC cells, followed by AddModuleScore, pathway enrichment, Pseudo-time, and Scenic analyses. Data from a gastric cancer (GC) cohort were collected for conjoint analysis. The analytical results were verified by cell experiments and immunohistochemistry.

RESULTS

AFPGC cells are similar to hepatocytes in transcriptome and transcriptional regulation, with kinetic malignancy-related pathways, compared to the common malignant epithelium. In addition, compared to common GC cells, malignancy-related pathways, such as epithelial-mesenchymal transition (EMT) and angiogenesis, were upregulated in AFPGC. Mechanistically, Dickkopf-1 (DKK1) was found to be associated with AFP expression and malignant phenotype upon combining our scRNA-seq data with a public database, which was further verified by a series of in vitro experiments and immunohistochemistry.

CONCLUSION

We demonstrated the single-cell characteristics of AFPGC and that DKK1 facilitates AFP expression and malignancy.

Alpha-Fetoprotein (AFP)-Negative Hepatoid Adenocarcinoma of the Stomach and its Associated Uncommon Features With a Review

Hepatoid adenocarcinoma of the stomach is a rare histologic subtype of gastric carcinoma. Morphologically, it shows hepatocyte-like features and the tumor cells can show the expression of alpha-fetoprotein (AFP) in the tumor cells as well as in serum. There are a few AFP-negative hepatoid adenocarcinoma tumors that have been reported in the literature. A 45-year-old male patient presented with abdominal pain. Endoscopy and radiological studies showed an ulceronodular thickening in the antropyloric thickening with lymphadenopathy. He underwent radical subtotal gastrectomy with lymph node dissection. Microscopic examination showed adenocarcinoma with hepatocytic morphology, the presence of lymphovascular and perineural invasion, prominent peritumoral lymphocytic infiltration, multiple metastatic tumor deposit involving regional lymoh nodes and omentum. Adjacent gastric mucosa showed Helicobacter pylori-associated chronic atrophic gastritis with intestinal metaplasia. On immunohistochemistry (IHC), tumor cells were immunopositive for keratin 7, CDX2, and HepPar-1, p53 (focal), and MUC5AC (focal) while immunonegative for AFP, SALL4, MUC2, CD10, and HER2 (ERBB2) was negative. We report this AFP-negative hepatoid adenocarcinoma with its associated uncommon features and discussed the literature review and diagnostic approach.

The Clinicopathological Characteristics of Alpha-Fetoprotein-Producing Adenocarcinoma of the Gastrointestinal Tract-A Single-Center Retrospective Study

Alpha-fetoprotein (AFP)-producing adenocarcinoma from the gastrointestinal tract (APA-GI) is a rare type of highly malignant tumor with a poor prognosis. It may originate from any site along the GI tract with similar clinicopathological characteristics. As limited research had ever described the characteristics of APA-GI, the present article intends to systemically investigate the clinicopathological characteristics of APA-GI from a single center's retrospective study to deepen the understanding of the disease. A total of 177 patients pathologically diagnosed with APA-GI between 2010 and 2017 at the Second Affiliated Hospital of Zhejiang University, School of Medicine, were included. Also, clinical data of 419 gastric cancers and 609 colorectal cancers from The Cancer Genome Atlas database were also extracted. Clinical information of patients from Second Affiliated Hospital of Zhejiang University, School of Medicine, was collected, and a median follow-up of 14.5 months was performed to investigate clinical characteristics of APA-GI. For the pathological characteristics of APA-GI, hematoxylin-eosin sections were reviewed, and immunohistochemistry of AFP was performed. The results showed that the primary tumor could develop through the whole GI tract, including the esophagus (0.6%), stomach (83.1%), duodenum (1.1%), ileum (0.6%), appendix (0.6%), colon (5.1%), and rectum (7.9%). Hepatoid adenocarcinoma is the main pathological feature of APA-GI. AFP expression level in tumor tissue was not strictly associated with serum AFP or hepatoid differentiation. The prognosis of APA-GI was worse than that of common adenocarcinoma of the GI tract and liver metastasis, and high AFP levels suggest poor prognosis in patients with APA-GI. Therefore, the present study was the first research to systemically explore the clinicopathological characteristics of APA-GI. APA-GI occurs through the whole GI tract with a significantly worse prognosis than common adenocarcinoma of GI. APA-GI should be regarded as one kind of disease for its similar clinicopathological characteristics within patients.

A Unique Case of Alpha-Fetoprotein-Negative Hepatoid Adenocarcinoma of the Stomach With Associated Signet Ring Cell Histological Features and Linitis Plastica

Hepatoid adenocarcinoma of the stomach (HAS), a rare and unique histological subtype of gastric cancer, accounts for less than 1.5% of all gastric cancers. Historically, this subtype is found to have a poor prognosis in comparison to other types of gastric cancer. While the diagnosis is made based on pathological findings, most cases described in the literature are associated with elevated alpha-fetoprotein (AFP) levels. We present a case of AFP-negative HAS with additional unique pathologic findings of signet ring cells which has been reported only once in the literature. Given the rare and late presentation of the disease, AFP-negative HAS should be included in the differential diagnosis in patients with suspicion for gastric cancer.

Albumin In Situ Hybridization Can Be Positive in Adenocarcinomas and Other Tumors From Diverse Sites

OBJECTIVES

Albumin messenger RNA (mRNA) expression is a marker of hepatocellular differentiation. Most published data are from review of tissue microarrays, and albumin in situ hybridization (ISH) expression across several tumor types is incompletely characterized.

METHODS

Sections from 221 tumors were evaluated for albumin mRNA. Immunohistochemistry was used to confirm diagnoses. Albumin ISH was performed according to manufacturer-provided instructions. Fifty-nine cases were evaluated with both commercial ISH assays.

RESULTS

Albumin mRNA was detected in all hepatocellular carcinomas (HCCs) and 81% of intrahepatic cholangiocarcinomas. Lung (20%), gallbladder (39%), hepatoid pancreatic (n = 1 of 1) adenocarcinoma, breast invasive ductal carcinoma (18%), yolk sac tumor (25%), and acinar cell carcinoma (29%) showed expression. Both assays were concordant in 93% of cases.

CONCLUSIONS

Albumin ISH was expressed in all HCCs studied. It was also positive in intrahepatic cholangiocarcinoma and patchy positive in gallbladder adenocarcinoma and a subset of other neoplasms, which can be a potential pitfall.

Hepatoid Adenocarcinoma of the Extrahepatic Bile Duct in a Patient with Polysplenia Syndrome

Hepatoid adenocarcinoma (HAC) is a rare subtype of extrahepatic adenocarcinoma that is characterized by its morphological and functional similarities to hepatocellular carcinoma. We herein present a novel case of HAC arising from the extrahepatic bile duct in a 75-year-old Japanese woman with polysplenia syndrome. This is the second reported case of HAC arising from this site. The tumor induced jaundice and hemobilia. A total of four isolated intraductal polypoid masses of HAC were found. No recurrence was seen five months after surgery. Further reports of similar cases will be needed to clarify the clinical characteristics and the prognosis of this malignancy.

Expression of Markers of Hepatocellular Differentiation in Pancreatic Acinar Cell Neoplasms: A Potential Diagnostic Pitfall

OBJECTIVES

Pancreatic acinar cell carcinoma (ACC) is a rare tumor that frequently metastasizes to the liver and may present a diagnostic challenge due to its morphologic similarity to hepatocellular carcinoma. We investigated α-fetoprotein (AFP), hepatocyte paraffin antigen 1 (HepPar 1), glypican 3, arginase 1, and albumin messenger RNA (mRNA) in situ hybridization (ISH) in pancreatic neoplasms with ACC differentiation to assess their diagnostic value.

METHODS

AFP, HepPar 1, glypican 3, and arginase 1 immunohistochemical staining was performed on 28 ACCs using a tissue microarray. Albumin mRNA ISH was performed on full-faced sections.

RESULTS

Fifteen tumors were positive for at least one marker. Glypican 3 was positive in seven of 28, AFP in five 28, and albumin mRNA ISH in five of 20. None expressed arginase 1.

CONCLUSIONS

Hepatocellular differentiation markers, including albumin mRNA ISH, may be positive in ACC, but arginase 1 appears to be uniformly negative. Thus, its use may improve the accuracy in distinguishing these neoplasms from hepatocellular carcinoma. If ACC diagnosis is considered, acinar differentiation can be reliably demonstrated by trypsin/chymotrypsin.

Hepatoid adenocarcinoma of the stomach--proper identification and treatment remain a challenge

OBJECTIVE

The term hepatoid adenocarcinoma (HAC) of the stomach was introduced three decades ago with the observation of high serum α-fetoprotein (AFP) levels in some gastric adenocarcinoma patients. This very rare gastric cancer patient subgroup is likely frequently misdiagnosed.

MATERIAL

Two patients who were recently diagnosed with HAC of the stomach at our institution are presented. We also performed a structured literature search and reviewed pertinent articles to provide knowledge to improve the proper identification, diagnosis and management of patients with gastric HAC.

RESULTS

HAC is a rare subgroup of gastric carcinoma with poor prognosis. Clinical management of this population may be challenging. The scientific literature is largely based on very small patient series or case reports, and the evidence for proper decision making and management is considered weak.

CONCLUSION

All physicians involved in the diagnosis and treatment of patients with gastric cancer should pay attention to this rare subgroup to improve identification.

PRISMA-Compliant Article: Clinical Characteristics and Factors Influencing Prognosis of Patients With Hepatoid Adenocarcinoma of the Stomach in China

Most previous studies have been single case reports, and studies with large samples are presently lacking. In addition, no studies have investigated the associations between the clinical characteristics and prognosis of hepatoid adenocarcinoma of the stomach (HAS). The aim of this study was to explore the associations of different clinical characteristics with the ages, serum alpha-fetoprotein (AFP) levels, and survival times of HAS patients. The present study was conducted using the CBM disc, HowNet, Wanfang and VIP data resource systems, and PubMed. According to the PRISMA Flow Diagram, certain case reports from the same center, those that did not provide patient age or sex, and those that did not report serum AFP levels or AFP immunohistochemistry results were excluded. A total of 131 relevant articles, including 124 case reports, 5 reviews, and 2 postgraduate Master's theses, were reported in the above-mentioned five databases. We applied inclusion criteria to case reports on the clinical characteristics and prognosis of HAS, which resulted in the ultimate inclusion of 180 patients from 62 case reports for statistical analyses. The main finding was that the age of the men was significantly higher than that of the women (P = 0.004). In addition, the serum AFP levels of the participants with antral disease were significantly higher than those with nonantral disease (P = 0.001). The median serum AFP levels and survival times significantly differed among the patients with the three lesion types (P = 0.001 and 0.019, respectively). The serum AFP levels of the participants with ulcerative-upheaval-type tumors and purely ulcerative tumors were significantly higher than those with upheaval-type tumors (P = 0.000 and 0.017, respectively). In addition, the serum AFP levels of the participants with ulcerative-upheaval-type tumors were significantly higher than those with ulcerative-type tumors (P = 0.019), and their survival time was also significantly higher (P = 0.000). The serum AFP levels of the participants without metastasis or liver metastasis were significantly lower than those with metastasis or liver metastasis (P = 0.000 and 0.000, respectively), and their survival time was significantly longer (P = 0.000 and 0.001, respectively). Finally, the survival time of the participants treated with surgery was significantly longer than those treated using nonsurgical methods (P = 0.046). However, survival analysis revealed that the survival time was only significantly associated with the presence of metastasis (P = 0.002) and liver metastasis (P = 0.036). The main limitations of this study are as follows: it was a retrospective analysis of published case reports, the clinical data were incomplete, and the cases included in subgroup analyses were different. Our study results have demonstrated that the prognosis of HAS patients is poor. In addition, the survival time is significantly negatively correlated with the presence of metastasis and liver metastasis.

Hepatoid adenocarcinoma of the gallbladder with production of alpha-fetoprotein

Hepatoid adenocarcinoma (HAC) is a tumor with aberrant hepatocellular differentiation that occurs in extrahepatic organs. HAC of the gallbladder is rare, and cases of alpha-fetoprotein production are extremely rare. A 61-year-old man was diagnosed with gallbladder adenocarcinoma after laparoscopic cholecystectomy. A radical operation including resection of liver bed and lymph node dissection was performed, and no tumor cell was found. However, at postoperative 19 months, he showed lymphadenopathy of the portocaval area and tumor thrombi in the right portal vein with high levels of serum alpha-fetoprotein. After right hemihepatectomy and portahepatis lymph node dissection was performed, he was diagnosed with metastatic HAC. On reviewing the gallbladder specimen, the tumor finally demonstrated HAC as the primary origin. Despite adjuvant therapy, the patient died from multiple liver metastasis 26 months after cholecystectomy. Although HAC of the gallbladder is a very rare malignancy, awareness of its existence is critical to avoid misdiagnosis.

Morphologic and proteomic characterization of exosomes released by cultured extravillous trophoblast cells

Exosomes represent an important intercellular communication vehicle, mediating events essential for the decidual microenvironment. While we have demonstrated exosome induction of pro-inflammatory cytokines, to date, no extensive characterization of trophoblast-derived exosomes has been provided. Our objective was to provide a morphologic and proteomic characterization of these exosomes. Exosomes were isolated from the conditioned media of Swan71 human trophoblast cells by ultrafiltration and ultracentrifugation. These were analyzed for density (sucrose density gradient centrifugation), morphology (electron microscopy), size (dynamic light scattering) and protein composition (Ion Trap mass spectrometry and western immunoblotting). Based on density gradient centrifugation, microvesicles from Sw71 cells exhibit a density between 1.134 and 1.173g/ml. Electron microscopy demonstrated that microvesicles from Sw71 cells exhibit the characteristic cup-shaped morphology of exosomes. Dynamic light scattering showed a bell-shaped curve, indicating a homogeneous population with a mean size of 165nm ± 0.5nm. Ion Trap mass spectrometry demonstrated the presence of exosome marker proteins (including CD81, Alix, cytoskeleton related proteins, and Rab family). The MS results were confirmed by western immunoblotting. Based on morphology, density, size and protein composition, we defined the release of exosomes from extravillous trophoblast cells and provide their first extensive characterization. This characterization is essential in furthering our understanding of "normal" early pregnancy.

AFP-producing hepatoid adenocarcinoma of the stomach: a case report

Hepatoid gastric adenocarcinoma is a distinct variant of gastric carcinoma which represents a comparatively small percentage of the disease and in many cases is producing high serum alpha-fetoprotein (AFP). We report a case of an 85 year old woman who presented with epigastric and right upper quadrant pain and was found in a CT scan to have multiple liver nodules and a gastric antrum mass as well as an elevated AFP level of 155000 IU/ml. An endoscopic biopsy of the antral mass showed hepatoid variant of gastric adenocarcinoma. The patient refused any further treatment and died 4 months after diagnosis. Hepatoid gastric adenocarcinoma is considered to have a poor prognosis, although cases with survival of several years have been reported. Poor outcome in most of the cases is due to the fact that, as in our patient, metastatic disease is already present at diagnosis.

Hepatoid adenocarcinoma of the stomach with liver metastasis mimicking hepatocellular carcinoma: a case report

INTRODUCTION

Hepatoid adenocarcinoma is a special type of extrahepatic alpha-fetoprotein-producing adenocarcinoma, which has a morphologic similarity to hepatocellular carcinoma. We report a patient with underlying hepatitis B virus infection and hepatoid adenocarcinoma with liver metastasis mimicking hepatocellular carcinoma.

CASE PRESENTATION

We present the case of a 56-year-old Chinese female with underlying hepatitis B virus infection, who was found to have multiple hepatic tumors by abdominal ultrasound and an elevated level of serum alpha-fetoprotein. Hepatocellular carcinoma was considered based on the image findings, the elevated level of serum alpha-fetoprotein. and underlying hepatitis B virus infection. Moreover, the subsequent endoscopy revealed gastric tumor. However, the tumor histology of the stomach and liver revealed glandular adenocarcinoma with hepatoid foci. The final diagnosis is hepatoid adenocarcinoma of the stomach with liver metastasis.

CONCLUSION

Hepatoid adenocarcinoma is an aggressive tumor with liver metastasis being the first clinical manifestation of the neoplasm. Hepatoid adenocarcinoma of the stomach with liver metastasis should be considered in older patients with elevated serum alpha-fetoprotein and multiple hepatic tumors with underlying chronic liver disease. An upper gastrointestinal endoscopy should be performed to exclude the possibility of hepatoid adenocarcinoma originating from the stomach to avoid potential misdiagnosis and inappropriate therapy.

Gene expression profiling with microarray and SAGE identifies PLUNC as a marker for hepatoid adenocarcinoma of the stomach

Gastric cancer is one of the most common malignancies worldwide. In this study, we screened for genes upregulated in gastric cancer by comparing gene expression profiles from serial analysis of gene expression and microarray and identified the palate, lung, and nasal epithelium carcinoma-associated protein (PLUNC) gene. Immunostaining for PLUNC in 140 gastric cancer cases revealed strong and extensive staining of PLUNC in hepatoid adenocarcinoma of the stomach, whereas 7% of conventional gastric cancer cases showed focal immunostaining of PLUNC. Gastric hepatoid adenocarcinoma is an extrahepatic tumor characterized by morphologic similarities to hepatocellular carcinoma. To investigate the utility of PLUNC immunostaining in the diagnosis of gastric hepatoid adenocarcinoma, six cases of gastric hepatoid adenocarcinoma (six primary tumors and two associated liver metastases) were studied further. PLUNC staining was observed in all six primary hepatoid adenocarcinomas. PLUNC staining was observed in both the hepatoid adenocarcinoma and tubular/papillary adenocarcinoma components of primary tumors, although PLUNC staining was preferentially localized in tubular/papillary adenocarcinoma components. Staining of PLUNC was also detected in both liver metastases. PLUNC staining was not observed in 52 cases of primary hepatocellular carcinoma or in normal adult or fetal liver. These results indicate that PLUNC is a novel marker that distinguishes gastric hepatoid adenocarcinoma from primary hepatocellular carcinoma.

Application of immunohistochemistry to liver and gastrointestinal neoplasms: liver, stomach, colon, and pancreas

CONTEXT

Immunohistochemistry has become an integral component of the practice of pathology. Newer antibodies allow for increasingly precise diagnoses for tumors that previously could not be easily identified. Recently, immunohistochemical evaluations have begun to allow pathologists to actively assist in determining prognosis and even in selecting therapies.

OBJECTIVE

To summarize the usefulness of currently available immunostains for the study of liver and gastrointestinal system neoplasms and to make recommendations for panels of immunostains that can be particularly helpful.

DATA SOURCES

Information has been collected from recent literature as well as from personal experience and practice.

CONCLUSIONS

Many immunostains are now available for the practicing pathologist that allow for increasing accuracy in diagnosis of liver and gastrointestinal tract neoplasms. Panels of immunostains can be used to differentiate between various tumors and also to identify site of origin in the case of a metastatic neoplasm. Immunostains that allow for prognostic determinations and for guidance in the selection of chemotherapeutic agents can also be used by pathologists to assist in the management of patients with malignant tumors affecting the liver and gastrointestinal tract.

Hepatoid adenocarcinoma: computed tomographic imaging findings with histopathologic correlation in 6 cases

OBJECTIVE

Hepatoid adenocarcinoma (HAC) is a special type of primary tumor with aberrant hepatocellular differentiation occurring in extrahepatic organs. Our objective was to review the computed tomographic findings of HAC and to correlate the imaging features with histopathologic findings. Institutional review board approval was obtained for this study.

METHODS

The computed tomographic findings images in 6 consecutive patients with pathologically proven HAC were reviewed retrospectively. Five patients were men and 1 was a woman (mean age, 56 years; age range, 36-68 years). All patients underwent contrast-enhanced computed tomography (CT) performed on a 4-slice multidetector row CT scanner. The mean time interval between CT and surgery was 5 days. Two radiologists who were unaware of the final histological diagnosis reviewed all computed tomographic images retrospectively. Lesion characteristic (ie, number, location, size, density, enhancement, heterogeneity, margin, distribution, presence of necrosis, lymphadenopathy, and distant metastasis) were evaluated. The correlation between the imaging and the pathological findings was analyzed.

RESULTS

Most patients had elevated serum alpha-fetoprotein levels (n = 4). The HAC appeared as large tumors (mean size, 4.2 x 3.4 x 3.9 cm), isodense at unenhanced CT (n = 4), moderately enhanced (n= 5), with necrotic areas (n = 6), regional lymphadenopathy (n = 5), and distant metastases (n = 4). The heterogeneity on computed tomographic images correlated well with the presence of hemorrhage and necrosis.

CONCLUSIONS

In an old patient with a large necrotic and moderately vascular tumor, the presence of distant metastases, regional lymphadenopathy, and characteristic increased serum alpha-fetoprotein level may suggest a diagnosis of HAC.

Hepatocellular oncofetal protein, glypican 3 is a sensitive marker for alpha-fetoprotein-producing gastric carcinoma

AIMS

Glypican 3 (GPC3) is a cell surface heparan sulphate proteoglycan expressed specifically in the fetal liver and malignant neoplasms of hepatocyte lineage. The aim was to evaluate the significance of GPC3 in alpha-fetoprotein (AFP)-producing gastric carcinoma (GC) and other forms of GC.

METHODS AND RESULTS

We immunohistochemically evaluated GPC3 expression in representative cases of AFP-producing GC and in a tissue microarray of a consecutive series of GCs with other markers of hepatocyte lineage (AFP, PIVKA-II and hepatocyte antigen, HEP). In a series of 10 cases of AFP-producing GC, we observed immunohistochemical positivity for GPC3, PIVKA-II and HEP in 10, three and three cases in components with a hepatoid pattern and in nine, two and five cases in components with a non-hepatoid pattern, respectively. In a series of 118 cases of GC, we observed positivity for AFP, GPC3, PIVKA-II and HEP in one (0.8%), four (3.4%), six (5.1%) and 26 cases (22%), respectively. GPC3 was observed concurrently with AFP and discordantly with PIVKA-II and HEP. GPC3 positivity was clearly stronger in a larger area compared with immunoreactivity for AFP.

CONCLUSIONS

GPC3 is a sensitive marker for AFP-producing GC and its hepatoid component and is therefore useful to identify this aggressive subgroup of GC.