Alpha-fetoprotein (AFP)-producing gastric carcinoma. Is it hepatoid differentiation?

α‑Fetoprotein‑positive hepatoid adenocarcinoma of the stomach and a new classification: A case report

α-Fetoprotein (AFP)-producing gastric carcinoma (AFPGC) is a rare subtype of gastric cancer (GC) with controversial classification methods. Hepatoid adenocarcinoma of the stomach (HAS) is another rare subtype of GC. Its definition intersects with that of AFPGC, but it is much rarer. The present report describes the case of an elderly patient with GC and AFPGC and HAS features in a serum test and pathology, respectively, and proposes a new classification of GC subtypes based on histological and AFP-producing features. A 75-year-old woman presented with a history of polydipsia and polyuria for over a decade and dizziness for 1 day. Serum AFP levels gradually elevated from 183.70 to 397.70 ng/ml in 1 month after the patient's first clinic visit. Subsequent pathological findings from endoscopic biopsy samples confirmed a hepatoid focus with positive immunohistochemical staining for AFP. The patient underwent a laparoscopic-assisted radical total gastrectomy and esophagojejunal Roux-en-Y anastomosis, and the serum AFP levels decreased to the normal range after the surgery. The present case indicates the diagnostic value of both the serum AFP level and pathological examinations in the diagnosis of AFPGC and HAS, and also highlights the contemporary circumstances of the vague classification based on different criteria for these two subtypes. Furthermore, the present report proposes a new classification considering both histological and AFP-producing features (using both serum biomarkers and immunohistochemistry tests) to cover all cases encompassed by AFPGC and HAS under all definition methods. This new method would give more precise diagnoses and add value to the subsequent treatment decision-making.

Primary hepatoid adenocarcinoma of the lung with extremely elevated serum AFP: a case report and literature review

Primary hepatoid adenocarcinoma of the lung (HAL) is an exceptionally rare subtype of lung cancer that mimics the morphology and biological behavior of hepatocellular carcinoma. Although reports in the literature are limited, HAL is known for its high malignancy and poor prognosis, thus drawing increasing attention. We present the case of a patient with a mass-like consolidation with central necrosis initially misdiagnosed as inflammation at another medical institution despite a percutaneous lung biopsy. After ineffective anti-inflammatory treatment, she was referred to our hospital. We performed another lung biopsy, obtaining five samples from different angles, and eventually diagnosed her with HAL. Surprisingly, her serum alpha-fetoprotein (AFP) levels were extraordinarily high, leading to the successful diagnosis of HAL. Here, we present a case report and a related literature review.

Combinational zimberelimab plus lenvatinib and chemotherapy for alpha-fetoprotein elevated, advanced gastric cancer patients (AFPGC): a phase 1 dose-escalation study

BACKGROUND

Alpha-fetoprotein elevated gastric cancer (AFPGC) got growing interests for its aggressive nature and unfavorable prognosis. Here, a phase 1 dose escalation study was conducted to evaluate safety and efficacy of zimberelimab (GLS-010, anti-PD-1) plus lenvatinib and chemotherapy (XELOX) as the first-line treatment for AFPGC.

METHODS

Histologically confirmed HER2-negative, advanced GC patients with elevated serum AFP level (≥ 20 ng/ml) were screened. Using a 3 + 3 dose escalation design, patients were administered varying doses of lenvatinib (12, 16, 20 mg) with GLS-010 and XELOX. The primary endpoints were safety and determination of recommended phase II dose (RP2D). Secondary endpoints included overall response rate (ORR), progression-free survival (PFS) and disease control rate.

RESULTS

Nine patients were enrolled with no dose-limiting toxicities observed. Most frequent treatment-related AEs were fatigue (55.6%), hand-foot syndrome (55.6%) and rash (55.6%), and no grade ≥ 4 AEs were reported. All patients exhibited disease control with ORR reaching 33.3%. The median PFS and OS reached 7.67 months (95% CI 4.07-11.27) and 13.17 months (95% CI 2.78-23.56), respectively. Serum AFP level was found correlated with therapeutic responses. Further 16s rRNA sequencing analysis demonstrated altered gut microbiota with elevated abundance of Lachnospiraceae bacterium-GAM79 and Roseburia hominis A2-183.

CONCLUSIONS

GLS-010 plus lenvatinib and XELOX demonstrated a manageable safety profile with promising efficacy for AFPGC. With RP2D of lenvatinib determined as 16 mg, further expansion cohort is now ongoing. Translational investigation suggested that serum AFP can be indictive for therapeutic responses and certain microbiota species indicating favorable responses to immunotherapy was elevated after the combinational treatment.

Elevated Serum Alpha-Fetoprotein Is a Significant Prognostic Factor for Patients with Gastric Cancer: Results Based on a Large-Scale Retrospective Study

Objectives

The aim of this work is to study the clinicopathological features and prognostic factors of serum alpha-fetoprotein (AFP)–positive gastric cancer (GC).

Methods

A cohort study including 2,318 patients with GC who underwent radical surgery from January 2008 to December 2015 was retrospectively analyzed. Patients were divided into two groups according to preoperative serum AFP values: 191 patients with AFP-positive GC (AFP > 20 ng/ml, 8.24%) and 2,127 patients with AFP-negative GC (AFP ≤ 20 ng/ml, 91.76%). The clinicopathological features and prognostic factors were explored.

Results

Compared with AFP-negative GC, AFP-positive GC had higher rates of liver metastasis, lymph node metastasis, venous invasion, and nerve invasion (all P < 0.05). The 5-year OS, DFS, and mLMFS of AFP-positive GC were shorter than AFP-negative GC (55.00% vs. 45.04%, P < 0.001; 39.79% vs. 34.03%, P < 0.001; 13.80 months vs. 16.25 months, P = 0.002). In whole cohort, multivariate analysis found that serum AFP levels (positive vs. negative), pT stage, pN stage, nerve invasion (yes or no), and venous invasion (yes or no) were independent prognostic factors. Serum AFP levels (20–300 ng/ml vs. 300–1,000 ng/ml vs. >1,000 ng/ml), pT stage, pN stage, and venous invasion (yes or no) were independent prognostic factors in AFP-positive GC.

Conclusion

Liver metastases and venous invasion are more likely to occur in AFP-positive GC and lead to poor prognosis. Serum AFP level is an independent prognostic factor in patients with GC. As the level of AFP increases, the prognosis becomes worse.

Hepatoid Adenocarcinoma of the Lung

Hepatoid adenocarcinoma of the lung (HAL) is an comparatively rare malignant tumor originating from the lung with shorter survival. HAL morphologically and pathologically exhibits hepatocellular carcinoma (HCC)-like characteristics, while its clinical features resemble pulmonary adenocarcinoma. High concentration of alpha-fetoprotein (AFP) is often detected in the serum of HAL patients with no hepatic occupying lesion. Patients with AFP-negative HAL survive a few months longer than those with positive AFP test. HAL is a rare type of carcinoma, so there is a lack of systematic and extensive statistical research. The treatment strategy for HAL is similar to common lung adenocarcinoma. Complete surgical resection and adjuvant chemotherapy are the current major treatments for HAL patients. There are also a few of case reports suggesting that HAL patients may benefit from immunotherapy and targeted therapy. This review focuses on the clinical and pathological features, immunohistochemical staining characteristics, treatment and prognosis of HAL.

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.

Alpha-Fetoprotein-Producing Early Gastric Cancer with Intramucosal Hepatoid and Fetal Enteric Differentiation

Alpha-fetoprotein (AFP)-producing gastric carcinomas (AFPGCs) are relatively rare tumors known to have a poor prognosis and commonly found as advanced lesions. Histologically, AFPGCs have been described as having hepatoid and fetal enteric (enteroblastic) morphology and are associated with conventional adenocarcinomas. Prior studies reported a hepatoid component present only in invasive areas and hypothesized that AFPGCs may develop hepatoid features during the process of tumor invasion. We report three cases of AFP-producing early gastric cancer which had an intramucosal hepatoid component. Immunohistochemistry showed that the hepatoid component was diffusely immunoreactive for SALL4, AFP, arginase-1, and HepPar1, and focally for CDX2 and PDX1. An intramucosal transition between the hepatoid component and conventional intramucosal adenocarcinoma was identified. Two patients also had a coexistent fetal enteric component, which was admixed with a hepatoid component. Although at an early stage one patient subsequently developed liver metastasis and a second patient was suspected of having liver metastasis, these were not biopsy-proven. The latter patient had a previous history of hepatocellular carcinoma (HCC) and SALL4 was used on the HCC to distinguish metastatic/further HCC from a gastric metastatic primary with hepatoid differentiation.

Prognostic value of serum alpha-fetoprotein levels in patients with gastric cancer: a meta-analysis

Background

Methods

Results

Conclusions

Clinicopathological features and prognosis of AFP-producing colorectal cancer: a single-center analysis of 20 cases

Background: High serum levels of alpha-fetoprotein (AFP) are observed in some gastrointestinal cancers. However, primary AFP-producing colorectal cancer (CRC) is extremely rare and causes confusion among clinicians. In this study, we analyzed the clinicopathological features and clinical outcomes of AFP-producing CRC and provide a brief view of this rare carcinoma.

Patients and methods: Twenty patients with AFP-producing CRC were enrolled at the Fudan University Shanghai Cancer Center from 2012 to 2015. Clinical information, including serum AFP and CEA levels, and outcomes were collected. Tumors were divided into three histologic types: the common adenocarcinoma (COM) type, mucinous adenocarcinoma type and hepatoid type (HPT). Immunohistochemical (IHC) staining of GPC3, Hepa-1, SALL4 and Arg-1 was performed. Additionally, mutations of the KRAS, NRAS and BRAF genes were examined. Finally, another 40 stage-matched patients with traditional CRC were enrolled as controls for survival analysis.

Results: AFP-producing CRC was more likely to occur in males (60%) and arose mainly from the ascending (40%) and sigmoid (35%) colon. In addition, the majority of patients with AFP-producing CRC had poor differentiation (50%), advanced local invasion (80%) and lymph node (LN) metastasis (60%). Synchronous distant metastasis was commonly observed (35%). Interestingly, serum AFP levels were closely associated with LN metastasis. Histopathologically, the COM type was the most common pattern. In IHC staining, the HPT pattern was the most distinct due to high positivity rates of GPC3, Hepa-1 and Arg-1. One patient had mismatch repair deficiency, and another had a KRAS mutation. Patients with AFP-producing CRC had worse progression-free and overall survival than patients with traditional CRC.

Conclusion: AFP-producing CRC has unique clinical and histopathological characteristics, showing an aggressive biological behavior and worse prognosis than traditional CRC.

Gastric hepatoid adenocarcinomas are a genetically heterogenous group; most tumors show chromosomal instability, but MSI tumors do exist

The Cancer Genome Atlas Research Network classified gastric adenocarcinoma into four molecular subtypes: (1) Epstein-Barr virus-positive (EBV), (2) microsatellite-instable (MSI), (3) chromosomal instable (CIN), and (4) genomically stable (GS). The molecular subtypes of gastric hepatoid adenocarcinomas are still largely unknown. We analyzed 52 hepatoid adenocarcinomas for the expression of surrogate markers of molecular subtypes (MLH1, p53, and EBER in situ hybridization) and some biomarkers (p21, p16, Rb, cyclin D1, cyclin E, β-catenin, Bcl-2, IMP3, ARID1A and HER2), and mutations of TP53, CTNNB1, KRAS, and BRAF. We analyzed 36 solid-type poorly differentiated adenocarcinomas as a control group. Hepatoid adenocarcinomas were categorized as follows: EBV group (EBER-positive), no cases (0%); MSI group (MLH1 loss), three cases (6%); "CIN or GS" (CIN/GS) group (EBER-negative, MLH1 retained), 49 cases (94%). In the CIN/GS group, most of the tumors (59%) had either p53 overexpression or TP53 mutation and a coexisting tubular intestinal-type adenocarcinoma component (90%), suggesting that most hepatoid adenocarcinomas should be categorized as a true CIN group. Hepatoid adenocarcinomas showed relatively frequent expressions of HER2 (score 3+/2+: 21%/19%). Hepatoid adenocarcinomas showed shorter survival, more frequent overexpressions of p16 (67%) and IMP3 (98%) than the control group. None of hepatoid adenocarcinomas had KRAS or CTNNB1 mutations except for one case each, and no hepatoid adenocarcinomas had BRAF mutation. In conclusion, gastric hepatoid adenocarcinomas are a genetically heterogenous group. Most hepatoid adenocarcinomas are "CIN," but a small number of hepatoid adenocarcinomas with MSI do exist. Hepatoid adenocarcinomas are characterized by overexpressions of p16 and IMP3.

Early Gastric Cancer with Purely Enteroblastic Differentiation and No Conventional Adenocarcinoma Component

Gastric carcinoma with enteroblastic differentiation (GCED) is a rare variant of gastric carcinoma, and a part of GCED produces alpha-fetoprotein. GCED is characterized by cells with clear cytoplasm and a tubulopapillary and solid growth pattern resembling those in the primitive gut. GCED is typically overlaid by a conventional adenocarcinoma (CA) component, implying that CA in the mucosa differentiates into GCED during tumor invasion and proliferation. We present the case of a 73-year-old woman with a 10-mm superficial elevated lesion and a slight central depression at the anterior wall of the lower gastric body. Endoscopic submucosal dissection revealed tumor cells having clear cytoplasm and severely atypical nuclei characteristic of GCED. The growth pattern was predominantly solid and trabecular but included submucosal layer invasion and limited tubular growth. Atrophic pyloric mucosa without intestinal metaplasia surrounded the tumor. Immunohistochemically, the tumor cells were positive for AFP, GPC3, and SALL4. The present patient showed a purely enteroblastic differentiation without a CA component despite the presence of early cancer, indicating that few cases of GCED may arise de novo in the gastric mucosa. GCED is more aggressive compared with CA; therefore, pathologists should be aware that GCED without CA can appear in biopsy specimens of early cancer while making an accurate diagnosis.

Multimodality Treatment Including Triplet Regimen as First-Line Chemotherapy May Improve Prognosis of Serum AFP-Elevated Gastric Cancer with Liver Metastasis

Serum α-fetoprotein- (AFP-) elevated gastric cancer is a rare tumor that has a poor prognosis due to high incidence of liver metastasis. This study sought to investigate the optimal treatment modality. A total of 319 gastric cancer patients with liver metastasis (GCLM) whose serum AFP levels were tested before treatment were enrolled in this study. They were classified as the serum AFP ≥ 20 ng/ml group (n = 74) and the AFP < 20 ng/ml group (n = 245). Median OS of the AFP < 20 ng/ml group was significantly longer than that of the AFP ≥ 20 ng/ml group (15.7 m versus 10.9 m, P = 0.004). ORR of first-line chemotherapy was 43.3% and 56.1% of the two groups, respectively (P = 0.024). Of patients who received doublet regimen, ORR of the AFP ≥ 20 ng/ml group was significantly lower (38.2 versus 56.9%, P = 0.013), while in those received triplet regimens, ORR between two groups was similar (66.7% versus 66.7%, P = 0.676). Moreover, for patients of the AFP ≥ 20 ng/ml group, those who reached PR had a longer survival period (15.4 m versus 9.4 m, P = 0.017), and combined with local treatment for liver metastasis also seemed to improve prognosis (19.2 m versus 8.4 m, P = 0.003). In conclusion, serum AFP-elevated GCLM had a poorer prognosis. Multimodality treatment including aggressive first-line chemotherapy with triplet regimen may be needed when treating them.

Chemotherapy for alpha-fetoprotein producing gastric cancers expressing human epidermal growth factor receptor 2

Although, gastric cancer is one of the most common cancers worldwide, alpha-fetoprotein (AFP) producing human epidermal growth factor receptor 2 (HER2) positive gastric cancers are rare. AFP producing gastric cancer has a poor prognosis and an appropriate treatment option has not been established to date. A 75-year-old woman with AFP- producing gastric cancer was treated with S-1, an oral fluoropyrimidine derivative, chemotherapy after distal gastrectomy. Recurrence of gastric cancer was observed after 18 months and immunohistochemistry analysis showed AFP and HER2 positive gastric cancer. The patient received combination therapy containing capecitabine, cisplatin, and trastuzumab. Computed tomography scans showed regression of the lymph node metastasis. The patient's quality of life substantially improved after the treatment. Thus, the present case suggests that AFP and HER2 positive gastric cancer can be effectively treated with, capecitabine, cisplatin, and trastuzumab combination therapy.

Efficacy and safety of SOX chemotherapy with or without surgery in AFP-producing advanced gastric cancer

The present study investigated the clinical efficacy of S-1 plus oxaliplatin (SOX) regimen, with or without surgery in α-fetoprotein-producing gastric cancer (APGC) with liver metastasis. A total of 24 patients with APGC treated at the Liaocheng People's Hospital between January 2011 and December 2013 were retrospectively reviewed. Clinical efficacy and patient safety were compared between the two groups. The median progression-free survival (PFS) and overall survival (OS) in the SOX group were 6.5 [95% confidence interval (CI), 4.6–8.4] and 13.5 (95% CI, 8.1–18.9) months, respectively. The corresponding indicators in the SOX and surgery group were 7.0 (95% CI, 5.7–8.3) and 14 (95% CI, 11.0–17.1) months, respectively. There was no significant difference in PFS and OS between the two groups (P=0.703 and 0.710, respectively). The adverse effects of leucopenia, neutropenia, anemia and diarrhea occurred in ~10% of patients in the SOX group and in 14.3% (2/14), 7.14% (1/14), 14.3% (2/14) and 7.14% (1/14), respectively, in the surgery group. No significant difference was identified between groups in terms of overall incidence of adverse effects (P=0.17). However, severe adverse events, including gastroplegia, pancreatic fistula, pulmonary infection and refractory ascites, occurred only in the SOX plus surgery group [incidence rate for severe adverse events, 7.14% (1/14); P<0.001 between groups]. In conclusion, SOX chemotherapy is safe and effective in patients with APGC and liver metastasis. However, the addition of surgery to SOX chemotherapy may not improve the disease control rate and may increase the adverse effects.

Alpha-Fetoprotein-Producing Extrahepatic Tumor: Clinical and Histopathological Significance of a Case

INTRODUCTION

The serum rise of alpha-fetoprotein (AFP) has been relationed to hepatic tumors. Other than these, such as gastric adenocarcinoma, can present with high levels of this glycoprotein. One rare kind of gastric adenocarcinoma, called hepatoid subtype, has two essential features: hepatoid differentiation in histology and high levels of AFP in serum.

DISCUSSIONS

We report a Spanish female who consulted because of fatigue, anorexia, and weight loss. In laboratory data, she presented anemia and markedly elevation of AFP. On CT scan, a gastric mass resulted without hepatic dissemination, and subsequently, gastroduodenoscopy was performed for histological diagnosis. Then, an ulcerated mass was detected and sample was taken, resulting in poorly-differentiated adenocarcinoma of stomach with hepatoid tissue foci, with intense positivity for AFP-immunohistochemical staining. This rare cancer has poor prognosis even with early gastrectomy and chemotherapy.

High level of serum AFP is an independent negative prognostic factor in gastric cancer

BACKGROUND

Gastric cancer with a high level of serum alpha fetoprotein (AFP) is uncommon and has unique clinicopathological features and a poorer prognosis. The aim of this research was to elucidate the clinicopathological and prognostic features of gastric cancer with a high level of AFP.

METHODS

The sera from 1,286 patients with gastric cancer treated at Qilu Hospital of Shandong University from January 2004 to December 2008 were analyzed preoperatively for AFP, CEA and CA19-9 levels after excluding active or chronic hepatitis, liver cirrhosis and hepatocellular carcinoma as well as preoperative distant metastasis. Patients were divided into 2 groups: 86 serum AFP-positive patients and 1,200 serum AFP-negative patients according to a cutoff of 20 ng/mL. The clinicopathological features and prognostic factors were compared between the groups.

RESULTS

A higher incidence of serosal invasion, lymph node metastasis and liver metastasis and poorer prognosis was observed in the AFP-positive group compared with the AFP-negative group (all p&lt;0.05). Serum AFP showed the highest specificity (93.66%) and diagnostic accuracy (92.38%) for predicting liver metastasis among the 3 tumor markers examined. Multivariate survival analysis revealed that AFP positivity was an independent prognostic factor in all 1,286 gastric cancer patients. The prognosis of AFP-positive gastric cancer was poorer than that of AFP-negative gastric cancer (p&lt;0.05).

CONCLUSIONS

A high level of serum AFP is an independent prognostic factor in gastric cancer and can be used for evaluating the prognosis of gastric cancers whether in the presence or absence of liver metastasis.

Hepatoid adenocarcinoma of the stomach: A case report and review of the literature

Hepatoid adenocarcinoma is a rare tumor, associated with an extremely poor prognosis. In the present report, a 72-year-old female presented to Huashan Hospital (Shanghai, China) with upper abdominal discomfort and, following endoscopy, an ulcerated lesion was observed in the stomach. A computed tomography scan revealed a mass in the antrum of the stomach and the α-fetoprotein level was normal. Sections of the mass exhibited malignant cells arranged in a solid to trabecular pattern; the cells were polygonal shaped with well-defined cytoplasmic borders. Immunohistochemical analysis was performed and the cells were positive for Hep1, CK, CK8, CK18 and P53. The histological features together with the immunohistochemical findings were diagnostic of a hepatoid adenocarcinoma of the stomach. Immunohistochemical studies may aid in the identification of the characteristic features and prevent the misdiagnosis of this tumor.

α-Fetoprotein-producing gastric carcinoma and combined hepatocellular and cholangiocarcinoma show similar morphology but different histogenesis with respect to SALL4 expression

α-Fetoprotein is expressed in hepatocellular carcinoma, yolk sac tumor, and some gastric carcinomas. The α-fetoprotein-producing gastric carcinoma composed of hepatoid and common adenocarcinoma shows morphological similarities to combined hepatocellular and cholangiocarcinoma. In this study, the expression of putative hepatic stem/progenitor markers (EpCAM, OV-6, DLK-1, and NCAM/CD56), hepatocyte markers (HepParI, α-fetoprotein, glypican 3), and the germ cell marker SALL4 was examined in α-fetoprotein-producing gastric carcinoma (20 cases) and combined hepatocellular and cholangiocarcinoma (20 cases) for evaluation of pathologic differentiation and also the histogenesis of both tumors. The SALL4 protein was expressed in 95% of α-fetoprotein-producing gastric carcinoma, including the hepatoid component (hepatoid gastric carcinoma), but was absent in combined hepatocellular and cholangiocarcinoma. Glypican 3 and α-fetoprotein were detected in all hepatoid-type α-fetoprotein-producing gastric carcinoma but variably in combined hepatocellular and cholangiocarcinoma. NCAM/CD56 was expressed focally in combined hepatocellular and cholangiocarcinoma but was rare in hepatoid gastric carcinoma. EpCAM, DLK-1, and OV6 were variably expressed in hepatoid gastric carcinoma and combined hepatocellular and cholangiocarcinoma. SALL4 was a useful differential marker for combined hepatocellular and cholangiocarcinoma and hepatoid gastric carcinoma. The histogenesis of hepatoid gastric carcinoma expressing SALL4 seems to reflect fetal gut differentiation or involve the germ cell lineage and may be different from that of combined hepatocellular and cholangiocarcinoma involving the hepatic stem cell or progenitor cell lineages. In conclusion, hepatoid gastric carcinoma and combined hepatocellular and cholangiocarcinoma shared morphologies, whereas the distinction of hepatoid gastric carcinoma from combined hepatocellular and cholangiocarcinoma is possible by immunostaining for SALL4. These 2 tumors seem to differ in their histogenesis with respect to SALL4 expression.1.

Huge pancreatic acinar cell carcinoma with high levels of AFP and fucosylated AFP (AFP-L3)

A 25-year-old Japanese woman with a large abdominal tumor (10 cm in diameter) and high level of serum alpha-fetoprotein (AFP, 1,222.4 ng/mL) was introduced and admitted to our hospital in January 2011. Pre-operative imaging modalities could not identify the tumor origin. There was no chronic hepatic viral disease, however, the elevated level of fucosylated AFP (87.8%) and connection with the left hepatic lobe led us to diagnose the tumor as a hepatocellular carcinoma. Surgical resection was performed in February. Histological findings revealed a pancreatic acinar cell carcinoma (ACC). Herein, we provide details of this difficulty to diagnose a case of ACC.

Clinicopathologic characteristics and treatment outcomes of hepatoid adenocarcinoma of the stomach, a rare but unique subtype of gastric cancer

BACKGROUND

Gastric hepatoid adenocarcinoma (HAC) is a special type of gastric cancer that morphologically mimics hepatocellular carcinoma. In this study, we performed an evaluation of clinicopathologic characteristics, treatment outcome, and prognosis in patients with gastric HAC.

METHODS

We consecutively enrolled patients with pathologically proven gastric HAC at Seoul National University Hospital between January 1996 and December 2008 and conducted a retrospective review. Among 15,253 patients with gastric cancer, 26 patients (0.17%) were diagnosed as gastric HAC.

RESULTS

Among 26 patients, 22 were male and the median age was 63. Stage at diagnosis was stage IB in 3 patients, stage II in 6 patients, stage III in 7 patients, and stage IV in 10 patients. Eight patients out of 18 patients with stage IB, II, III, and IV relapsed after curative surgery. Relapse-free survival for these patients was 16.67 months. The most common metastatic site was intraabdominal lymph nodes (n = 9), followed by the liver (n = 8). Thirteen patients received palliative chemotherapy. The most commonly used regimen was a combination of fluoropyrimidine and platinum. Partial response was observed in one patient and stable disease in 5 patients. Median overall survival and progression free survival of these patients were 8.03 (95% CI: 6.59-9.47) and 3.47 months (95% CI: 0.65-6.29), respectively.

CONCLUSIONS

Gastric HAC is a very rare but unique type of stomach cancer. Early detection of this type of cancer is of critical importance to patient prognosis. Additional studies to reveal the biology of this tumor are warranted.

Protein induced by vitamin K absence or antagonist II-producing gastric cancer

Protein induced by vitamin K absence or antagonist II (PIVKA-II) is a putative specific marker of hepatocellular carcinoma (HCC), but it may also be produced by a small number of gastric cancers. To date, 16 cases of PIVKA-II-producing gastric cancer have been reported, 2 of which were reported by us and all of which were identified in Japan. There are no symptoms specific to PIVKA-II-producing gastric cancer, and the representative clinical symptoms are general fatigue, appetite loss, and upper abdominal pain. Serum alpha-fetoprotein (AFP) levels are also increased in almost all cases. Liver metastasis is observed in approximately 80% of cases and portal vein tumor thrombus is observed in approximately 20% of cases. Differential diagnosis between metastatic liver tumor and HCC is often difficult. Grossly, almost all cases appear as advanced gastric cancer. Histologically, a hepatoid pattern is observed in many cases, in addition to a moderately to poorly differentiated adenocarcinoma component. The production of PIVKA-II and AFP is usually confirmed using immunohistochemical staining. Treatment and prognosis largely depends on the existence of liver metastasis, and the prognosis of patients with liver metastasis is very poor. PIVKA-II may be produced during the hepatocellularmetaplasia of the tumor cells.

SALL4 represents fetal gut differentiation of gastric cancer, and is diagnostically useful in distinguishing hepatoid gastric carcinoma from hepatocellular carcinoma

The novel stem cell marker SALL4 has been identified as a diagnostic marker of germ cell tumors, especially yolk sac tumors, in gonadal organs. To clarify the significance of SALL4 as an oncofetal protein, we investigated SALL4 expression by immunohistochemistry in non-neoplastic stomach and gastric carcinoma with particular emphasis on á-fetoprotein (AFP)-producing gastric carcinoma, as AFP-producing gastric carcinoma shares expression of AFP and glypican 3 (GPC3) with yolk sac tumors and hepatic neoplasms. A total of 338 gastric carcinomas, 60 hepatocellular carcinomas, and 48 cholangiocellular carcinomas were studied by immunohistochemistry on tissue microarrays. In addition, more detailed whole tissue section immunohistochemistry was performed on non-neoplastic gastric tissue from 5 adult and 8 fetal specimens, 6 hepatoblastomas, and 31 cases of AFP-producing gastric carcinomas. SALL4 expression was observed in the neofetal stomach in gestational week 9 and disappeared thereafter. It was also identified by tissue microarray study in a fraction of gastric carcinomas (51 of 338, 15%), associated with older age (P=0.0001), male sex (P=0.0033), intestinal-type histology (P=0.0001), and synchronous liver metastasis (P=0.0047). AFP and GPC3 were closely associated with SALL4 expression in gastric carcinoma (both, P<0.0001), and a full-section study indicated that SALL4 was positive in all 31 cases of AFP-producing gastric carcinoma with diffuse staining in 24 cases (78%). Diffuse SALL4 expression was observed in the histologic patterns of hepatoid (89%), glandular (57%), and clear cell (39%) AFP-producing gastric carcinoma. In addition, SALL4 expression was completely negative in hepatoblastoma (n=6) and hepatocellular carcinoma (n=60). SALL4 is an oncofetal protein similar to AFP and GPC3, but it represents fetal gut differentiation in gastric carcinoma. SALL4 is a sensitive marker for AFP-producing gastric carcinoma and is especially useful to distinguish hepatoid gastric carcinoma from hepatocellular carcinoma.

Lower- and higher-grade subtypes of diffuse gastric cancer

Diffuse gastric cancer, characterized by poorly cohesive, diffusely infiltrating cells with no or little gland formation, is known to show several morphologic variants, but their prognostic value, if any, is poorly documented. In this article, 119 cases of invasive (T1b to T4) diffuse gastric cancer, which had undergone potentially curative surgery and were followed postoperatively for a median time of more than 10 years, were investigated for histologic or histochemical patterns possibly predictive of survival. Among 5 histologic groups identified, a low-grade subtype (17 cases) with prominent desmoplasia closely surrounding individual tumor cells (tumor embedding desmoplasia) and no or scarce angio-lympho-neuroinvasion showed stage-independent improved survival compared with 36 non-low-grade desmoplastic, 24 signet ring, and 28 diffuse cancers not otherwise specified. Fourteen cases with anaplastic cells showed clinicopathologic patterns and outcome of highly malignant neoplasms. None of the tumor cell differentiation markers (including 6 mucins and 3 proteases) nor proliferative index or p53 protein expression had independent predictive power, although MUC1 was significantly less expressed in low-grade desmoplastic cases. Cox survival analysis showed the significantly better prognosis of 17 low-grade desmoplastic and worse prognosis of 14 anaplastic cancers compared with the remaining 88 cases. In conclusion, a low-grade desmoplastic and a high-grade anaplastic subtype should be separated histologically from the bulk of diffuse gastric cancers owing to their distinctive histologic, clinicopathologic, and prognostic aspects.

Hepatoid carcinoma of the skin: spontaneous rat skin hepatoid carcinoma with eosinophilic globules and crystals immunoreactive to alpha-1-antitrypsin

We present a case of hepatoid carcinoma of the abdominal skin in a male Wistar rat. Histopathologically, this carcinoma resembled human hepatocellular carcinoma with respect to trabecular-sinusoidal structures. Carcinoma tissues contain numerous eosinophilic globules and crystals, and in this case, we found the characteristic eosinophilic globules in the hepatoid carcinoma cells and the crystals in the extracellular portions. Vivid carcinoma cells full of eosinophilic globules were present near the necrotic areas in tumor tissue, wherein quadrate crystals unstained with eosin were observed. PAS staining after diastase digestion revealed that the globules were PAS positive and diastase resistant. In addition, we found that the hepatoid carcinoma cells were immunoreactive for alpha-1-antitrypsin (anti-A1AT) antibody with the globules and crystals staining peripherally, and a central unstained region. Ultrastructural study of intracytoplasmic globules and extracellular crystals revealed that the fringe of each globule and crystal had no limiting membrane and showed the same level of electron density. These findings suggest that the characteristic crystals in this tumor may have originated from the globules that were emitted from the carcinoma cells after their death as a result of saturation with intracytoplasmic globules.

Aberrant expression of alpha-fetoprotein in intrahepatic cholangiocarcinoma: an exceptional occurrence

A high level of serum alpha-fetoprotein (AFP) is typically indicative of hepatocellular carcinoma in patients with liver lesions. In this article, we describe an exceptional case of intrahepatic cholangiocarcinoma that occurred in a 36-year-old man with a markedly elevated serum AFP level (12310.7 ng/mL). Histopathologic examination of surgically resected liver mass showed classic morphologic features of cholangiocarcinoma, with no hepatocellular carcinoma component identified. Immunohistochemically, the tumor cells were strongly and diffusely positive for AFP, CA19-9, and cytokeratin 19 and were negative for hepatocyte antigen. The patient's serum AFP level declined to 46.2 ng/mL 1 month after surgery. To the best of our knowledge, this is the first documented case of AFP-producing intrahepatic cholangiocarcinoma with immunohistochemical evidence confirming the tumor cells to be the source of high-level AFP production.

Gastric hepatoid adenocarcinoma with autophagy-related necrosis-like tumor cell death: report of a case

A case of hepatoid adenocarcinoma of the stomach is presented. The characteristic features of the tumor are summarized on the basis of the authors' experience and the literature. Ultrastructural examination revealed patchy condensations of chromatin throughout the nucleus suggestive of necrosis-like programmed cell death (PCD). These nuclear alterations were associated with the occurrence of vacuoles and lipofuscins, conferring an autophagic phenotype to this PCD. Thus, the case reported here provides an example of autophagic-related necrosis-like PCD. Alternative PCDs are reviewed and their morphologic distinction is discussed.

Clear cell (glycogen-rich) gastric adenocarcinoma

Clear cells have been described in many tumors of varying differentiation. Although clear cell carcinoma is well-recognized in the lower urinary and female genital tracts, its occurrence in the gastrointestinal tract and related structures is uncommon. There have been only a few case reports and small series reporting this morphologic phenomenon in the stomach, colon, and biliary tract. Clear cell carcinoma of the endometrium has been associated with poor prognosis, but the prognostic significance of clear cells in gastric adenocarcinoma is unknown. Herein we describe three cases of clear cell, glycogen-rich, gastric adenocarcinoma and evaluate the frequently used classification systems for gastric cancer. Two tumors showed a tubulopapillary pattern and one showed a predominantly diffuse sheet-like growth. The proliferation (MIB) index in all cases was approximately 20%. Only case 1 showed focal staining for alpha-fetoprotein and both cases 1 and 2 showed focal carcinoembryonic antigen reactivity. In conclusion, we describe three cases of clear cell gastric carcinoma that presented as high-stage disease.

Des-gamma carboxy prothrombin (PIVKA-II) and alpha-fetoprotein producing gastric cancer with multiple liver metastases

We describe the case of an 87-year-old woman who presented to Tokyo Kousei Nenkin Hospital because of appetite loss and general fatigue. Multiple liver masses and Borrmann type 2 gastric tumor were detected. A clinical diagnosis of hepatocellular carcinoma and gastric cancer was made based on the patient's high levels of serum alpha-fetoprotein (AFP; 490 200 ng/mL) and protein induced by vitamin K absence or antagonist-II (PIVKA-II, 2284 mAU/mL). The patient's general condition worsened gradually and she died 42 days after admission. Autopsy revealed that the predominant histological structure of the gastric tumor was trabecular or sheet-like, although a tubular structure was also found. Venous invasion was prominent. Immunohistochemically, the tumor tissue was positive for AFP and a few tumor cells were positive for PIVKA-II. The histological appearance and immunohistochemical features of the hepatic tumors resembled that of the gastric tumor. This case was pathologically diagnosed as AFP- and PIVKA-II-producing gastric carcinoma with multiple liver metastases. When tumors are found in the stomach and liver and serum PIVKA-II level is abnormally high, the possibility of PIVKA-II-producing gastric cancer with liver metastasis should be considered, especially when hepatitis virus markers are negative and liver cirrhosis is not present.

Detection of serum alpha-fetoprotein in dogs with naturally occurring malignant neoplasia

Serum alpha-fetoprotein (AFP) concentrations were determined, by use of an automated microparticle enzyme-linked immunoassay (MEIA), in 16 control dogs and 48 dogs with previously untreated, histologically confirmed, naturally occurring neoplasia (17 dogs with lymphoma and 31 dogs with nonhematopoietic malignancies, 13 dogs with carcinomas, 18 dogs with sarcomas). Mean serum AFP concentrations for untreated dogs with lymphoma, for dogs with sarcomas, and for dogs with carcinomas were not significantly different from the mean serum AFP concentration for the 16 untreated control dogs. Mean serum AFP concentration for dogs with transitional cell carcinoma (n=7) was not significantly different from the mean serum AFP concentration for the control dogs. It has been shown previously by others that a mean serum AFP concentration > 225 ng/mL is suggestive of a hepatic malignancy (e.g., hepatocellular carcinoma, lymphoma). In our study, all 48 dogs had a normal complete blood count, serum biochemical analysis, and urinalysis. Only one of the 48 dogs was found to have a serum AFP concentration > 225 ng/mL. Later evaluation of this dog confirmed hepatic involvement with lymphoma. AFP can be detected in the serum of dogs with naturally occurring tumors using the MEIA technique. A serum AFP concentration above that observed in normal dogs is not a common finding in dogs with naturally occurring neoplasia; however, we confirmed that a serum AFP concentration > 225 ng/mL, with or without evidence of a serum biochemical abnormality, may suggest primary and/or secondary hepatic involvement with a neoplastic disease and may warrant an adjustment in clinical stage and prognosis. A prospective diagnostic and therapeutic evaluation of dogs, with naturally occurring tumors having an elevated serum AFP concentration would determine the validity of this conclusion.

Alpha-fetoprotein- and des-gamma-carboxy prothrombin-producing advanced gastric cancer

A case of alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) producing gastric cancer with multiple liver metastasis is reported. The simultaneous presence of Borrmann I gastric cancer and IIa aggregating type gastric cancer was noted. Borrmann I gastric cancer was a poorly differentiated adenocarcinoma, while IIa aggregating type gastric cancer was a moderately differentiated adenocarcinoma. Plasma levels of AFP and DCP were 247,000 ng/ml and 320,000 mAU/ml, respectively. Immunohistochemical staining confirmed the production of these two proteins in Borrmann I gastric cancer.

Alpha-fetoprotein producing uterine corpus carcinoma: A hepatoid adenocarcinoma of the endometrium

A case of alpha-fetoprotein (AFP) producing endometrial carcinoma in a 60-year-old Japanese woman is presented. The patient complained of abnormal vaginal bleeding of 10 days' duration. On admission a uterine corpus mass and high serum AFP concentration (31950 ng/mL) was noted. There was no tumorous lesion in any other organ radiographically and endoscopically. Histologically, the biopsy specimen taken from the uterine mass showed a poorly differentiated endometrial carcinoma and a radical hysterectomy was subsequently performed. The postoperative serum AFP value transiently decreased with chemotherapy, however, lung metastases were found and the patient died 12 months following surgery. The resected uterus had a necrotic tumor, 6 x 5 x 4 cm in size, filling the endometrial cavity, characterized by exophytic growth with infiltration in the myometrium. Histologically, the tumor was composed of the main medullary carcinoma area with microcysts and admixed small areas of well-differentiated endometrioid adenocarcinoma, accompanied by a smooth transition with one another. In both the areas, the tumor cells had immunoreactive AFP, alpha-1-antitripsin, albumin, transferrin, carcinoembryonic antigen, CA19-9, and epithelial membrane antigen. There was no histologic evidence for a germ cell tumor. Based on these findings, this uterine corpus tumor was regarded as hepatoid variant of endometrial carcinoma. Although the histogenesis remains controversial, we assume the hypothesis that the tumor may arise in the endometrium per se in association with abnormal differentiation of muellerian duct elements.

alpha-Fetoprotein-producing adenocarcinoma of the pancreas presenting focal hepatoid differentiation

We report a rare case of pancreatic carcinoma producing alpha-fetoprotein (AFP), showing focal hepatoid differentiation in metastatic lymph nodes. A 65-yr-old female was admitted because of abdominal pain. The serum AFP was measured at 16,170 ng/mL. Radiological examinations revealed a mass measuring 6 cm in diameter in the body and tail of the pancreas. A right supraclavicular lymphadenopathy was found and biopsied. Light microscopy showed a tumor consisting of a portion of a hepatoid area and well-differentiated adenocarcinoma, which was suggestive of a hepatoid adenocarcinoma. Immunohistochemical analysis showed that the tumor cells expressed AFP, alpha 1-antitrypsin (AT) and albumin. Although the pathological diagnosis of the primary pancreatic tumor was not obtained, this appears to be the first case of hepatoid adenocarcinoma of the pancreas.

Hepatoid adenocarcinoma of the lung: report of a case of an unusual alpha-fetoprotein-producing lung tumor

We report on a rare tumor of the lung characterized by its morphologic hepatoid features and alpha-fetoprotein production. This unusual neoplasm arose in the left lung of a 36-year-old man in whom clinical and radiologic examinations did not reveal any other tumor. The serum level of alpha-fetoprotein was measured at 6,090 ng/mL and was parallel to the evolution of the tumor. Despite treatment, the patient died 7 months after the diagnosis. The microscopic appearance of the tumor was the same as observed in hepatocarcinoma and hepatoid adenocarcinoma of the ovary or the stomach, with a tubular, papillary, or trabecular pattern. Periodic acid-Schiff-positive hyaline globules were numerous, and tumor cells showed immunohistologic positivity for alpha-fetoprotein and carcinoembryonic antigen. This lung adenocarcinoma was first described by Ishikura et al. in 1990 and was named hepatoid lung adenocarcinoma. Like the rare hepatoid carcinoma of the gallbladder, the pancreas, the ampulla of Vater, the renal pelvis, and the bladder, the exact histogenesis and the prognosis of this type of lung tumor are not yet known.

Double cancer of the stomach, one AFP-producing tumor

In recent years, many cases of alpha-fetoprotein-producing gastric cancer (AFPGC) characterized by increased serum levels of alpha-fetoprotein (AFP) and AFP positivity of the gastric cancer have been reported. Here we present a case of AFPGC coexistent with a different histological type of gastric cancer: The AFPGC was Borrmann type 1 advanced gastric cancer with multiple liver metastasis and appeared to produce both AFP and des-gamma-carboxy prothrombin (PIVKA-II). The second cancer was IIc type early gastric cancer and did not produce AFP. Despite receiving palliative chemotherapy, the patient died, due to hepatic failure, 45 days after admission.

Hepatoid Gastric Carcinoma. A Case Report

Alpha-fetoprotein (AFP) is normally produced by primary hepatic neoplasms and germ cell tumors. There have, however, been reports of its production in cases of gastrointestinal tract adenocarcinoma. Gastric hepatoid carcinomas constitute a clinicopathological entity of recent acquisition and have certain common characteristics, which include the presence of hepatoid foci and frequent liver metastases, even in cases of early gastric cancer, and increasing serum AFP levels. In this study the case of one patient who underwent gastric resection and presented clinical, humoral, histological and immunohistochemical characteristics typical of hepatoid gastric carcinoma is reported. More biological studies, as well as precise criteria for pathological definition and therapy, are still necessary for a better understanding of this pathology.

Biochemical characterization of alpha-fetoprotein and other serum proteins produced by a uterine endometrial adenocarcinoma

A high serum alpha-fetoprotein (AFP) level was found in a patient with endometrial adenocarcinoma of the uterus, which appeared to be hepatoid on histological examination. The AFP of this unusual patient was purified by immunoaffinity chromatography and characterized. The electrophoretic profiles on sodium dodecyl sulfate-polyacrylamide get electrophoresis both before and after glycopeptidase F treatment were indistinguishable from those of a hepatoma AFP. This indicates that the patient's AFP was also composed of a single polypeptide chain of Mr 67,000 and an N-linked sugar chain of Mr 3,000. Amino acid sequence analyses of this AFP, and of AFP from hepatoma and umbilical cord serum indicated that the N-terminal sequences were essentially the same. The sequence, Arg-Thr-Leu-His-Arg-Asn-Glu-Tyr-Gly-Ile, was slightly different from previous reports, but matched that deduced from the cDNA sequence. AFP isoforms due to microheterogeneity of the sugar chain were analyzed by lectin affinity electrophoresis using a series of lectins. The AFP isoform profiles were distinct from those of proteins derived from cord serum, hepatoma, yolk sac tumor and gastric cancer. The reverse-transcription of RNA from the tumor tissue followed by a polymerase chain reaction using primers with AFP-specific sequences gave a product of the size and nucleotide sequence expected for AFP. mRNAs possessing the requisite sequences for albumin and transferrin syntheses were also detected in the tumor. The expression of these hepatocyte-specific proteins supported the hepatoid nature of this tumor.

Alpha fetoprotein-producing acinar cell carcinoma of the pancreas showing multiple lines of differentiation

An alpha fetoprotein (AFP)-producing tumour occurring in the head of the pancreas of a 30-year-old woman is reported. Histological examination revealed a markedly solid proliferation of tumour cells with prominent nucleoli and occasional luminal structures, some of which contained mucinous material stained with mucicarmine and alcian blue. No squamoid corpuscles were recognized. Immunohistochemistry showed intense positivity for lipase trypsin, and AFP basically, and single cells were also positive for carcino-embryonic antigen, CA19-9, synaptophysin and neuron-specific enolase. Pancreatic hormone-positive cells were absent. Electron microscopical examination revealed numerous granules of variable sizes in the tumour cells, which were considered to be zymogen. The tumour is an acinar cell carcinoma with multi-directional differentiation including the ability to produce AFP. Among AFP-positive pancreatic tumours, acinar cell carcinoma and pancreatoblastoma seem to be the most frequent.

Use of lectins as diagnostic and therapeutic tools for cancer

Within the past few years, lectins have become a well-established means for understanding varied aspects of cancer and metastasis. Evidence is now emerging that lectins are dynamic contributors to tumor cell recognition (surface markers), cell adhesion and localization, signal transduction across membranes, mitogenic stimulation, augmentation of host immune defense, cytotoxicity, and apoptosis. To advance understanding of these lectin-dependent processes, attempts are being made to discover new lectins that have one or more of these functions and to develop lectin- (or glycoconjugate-) based tools that could be used to home in on tumor cells. This review will summarize current research on the lectins and recent advances in the development of lectin-based diagnostic and therapeutic tools for cancer. Additionally, the future potential of lectin-based diagnosis and therapy is discussed.

Alphafetoprotein-producing gastric adenocarcinoma

We report a rare gastric tumour characterized morphologically by its hepatoid features and alpha-fetoprotein production and which presented clinically with gastric haemorrhage. Gastric fibroscopy showed a bleeding tumour of the antrum. The microscopic appearance of the tumor showed two different patterns. The most extensive presented hepatoid features. The second pattern showed undifferentiated features. The tumour cells showed immunohistochemical positivity for alphafetoprotein, EMA and p53 protein; 37% were aneuploid with a DNA index of 1.46. The serum level of alphafetoprotein was not measured before the gastrectomy but after ten days it was elevated at 1070 ng/ml. The patient died 6 months after the admission. This case provides, for the first time, information on the DNA content and the p53 expression of this unusual and aggressive variant of gastric adenocarcinoma.

Different characteristics of hepatoid and non-hepatoid alpha-fetoprotein-producing gastric carcinomas: an experimental study using xenografted tumors

The characteristics, including metastatic potential, of 5 xenografts of alpha-fetoprotein (AFP)-producing gastric carcinomas in nude mice, designated TSG1, TSG3, TSG11, TSG17 and TSG20, were examined. Of these xenografts, TSG1, TSG11 and TSG20 were regarded as hepatoid adenocarcinomas based on their morphological resemblance to hepatocellular carcinoma, frequent immunoreactivity for liver-cell markers, and excessive production of AFP with a high concanavalin A (Con-A)-binding property of hepatic type. On the other hand, TSG3 and TSG17 tumors showed the features of poorly differentiated medullary adenocarcinoma with scattered AFP-positive cells consistent with low AFP levels in mouse sera, and negative immunoreactivity for other liver-cell markers. Ultrastructurally, these tumors were composed of undifferentiated cells with a little adenocarcinomatous differentiation. Moreover, the AFP produced by TSG3 and TSG17 tumors had an extremely high Con-A nonbound fraction (80% to 90%), which was different from that of the hepatic or yolk-sac types. Therefore, both TSG3 and TSG17 tumors were regarded as non-hepatoid, poorly differentiated adenocarcinomas which could be differentiated from any types of AFP-producing gastric carcinoma. Furthermore, cells from hepatoid adenocarcinoma strains (TSG1, TSG11 and TSG20) injected into the spleens of nude mice produced liver metastases in all the mice examined, whereas cells from non-hepatoid carcinoma strains (TSG3 and TSG17) produced few or no liver metastases. Our data show that some non-hepatoid AFP-producing gastric carcinomas have lower liver-metastasizing potential than hepatoid AFP-producing gastric carcinomas.

Evaluation of tumor-associated antigen (2H6 antigen) in detecting early stages of gastric cancer

A sandwich enzymed-linked immunosorbent assay (ELISA) was developed by using monoclonal antibody 2H6 (2H6 MoAb). MoAb 2H6 could be used to detect the 2H6 antigen in the sera of several cancers, showing positive rates of 65.4%, 66.7%, 47.4%, 80.0%, 45.2% and 16.7% in gastric cancer, hepatocellular carcinoma, cancers of the colon, esophagus, breast and pancreas, respectively. On the other hand, the positive rates in benign diseases or healthy donors were 3.4%, 3.4%, 4.2%, 8.3%, 6.9%, and 1.2% in myasthenia gravis, polymyositis, gastritis, gastric ulcer, other benign diseases and normal healthy donors, respectively. Fifty-two patients with gastric cancer were investigated in detail. The positive rates of serum 2H6 antigen, CEA, AFP, CA19-9 and CA125 in patients with gastric cancer were 65.4%, 9.6%, 2.3%, 25.0% and 8.1%, respectively. Among these tumor markers, serum 2H6 antigen levels alone were significantly elevated in patients with early stage (I and II) gastric cancer. Furthermore, combining the measurement for serum 2H6 with CA19-9 increased the percentage of gastric cancer slightly. No correlation between 2H6 antigen and these other tumor markers was observed. The serum levels of 2H6 antigen were monitored post-surgically in 11 patients for 12 weeks and they were found to diminish gradually. The findings suggest that the measurement of serum 2H6 antigen may be a useful marker for an early stage of gastric cancer.

Hepatoid adenocarcinoma in the urinary bladder. Unusual localization of a newly recognized tumor type

A tumor mass resected from the anterior bladder wall of a 68-year-old woman displayed unusual histologic features: sheets of hepatoid cells merging focally with a secondary glandular pattern of adenocarcinoma. Intracytoplasmic hyaline globules and bile production within the solid areas supported the impression of hepatocytic differentiation. Immunoreactivity for alpha-fetoprotein (AFP) and alpha-1-antitrypsin and a striking canalicular immunostaining pattern for carcinoembryonic antigen and epithelial membrane antigen all indicate hepatocellular differentiation within this bladder tumor. This represents a case of a hepatoid adenocarcinoma located in the urinary bladder. The use of the term "hepatoid" in the literature is reviewed and the reported cases are grouped into two distinct categories of tumors: (1) germ cell tumors with focal hepatoid areas and (2) true hepatoid adenocarcinomas that meet histologic and immunohistochemical criteria for hepatocellular differentiation. AFP-producing tumors without any other feature of hepatocellular differentiation should not be considered as hepatoid tumors. This classification of hepatoid tumors is likely to be important in elucidating the histogenesis and clinicopathologic features of these unusual neoplasms.

Alpha-fetoprotein-producing gastric carcinoma with enteroblastic differentiation

BACKGROUND

Alpha-fetoprotein (AFP) is a useful tumor marker for hepatoma and yolk sac tumor. Recently, elevations of serum AFP were reported in patients with other malignancies, especially gastric cancers. Two distinct tumor morphologies, hepatoid and clear cell, have been correlated with AFP production.

METHODS

Two patients with AFP-producing gastric carcinoma were evaluated with immunohistochemical, ultrastructural, and biochemical studies.

RESULTS

In Patient 1, the primary and metastatic carcinomas consisted homogeneously of tubulopapillary carcinoma with clear cytoplasm. In Patient 2, the cancer was composed of three different areas: tubulopapillary carcinoma with clear cytoplasm, tumor cartilage, and so-called hepatoid carcinoma. The morphologic characteristics of tubulopapillary carcinoma with clear cytoplasm were similar to those of the developing gut epithelium at the stage of 2-4 months' gestation. The elution patterns of the serum AFP on lectin-affinity sepharose column study also suggested a correlation with fetal gut differentiation.

CONCLUSIONS

AFP-producing clear cell gastric carcinomas are differentiated into fetal intestine. One patient also had hepatocytic and cartilaginous differentiation, indicative of a blastomatous characteristic of the tumor. These tumors arose in association with intestinal metaplasia.

alpha-Fetoprotein producing gastric carcinomas: a comparative study of three different subtypes

Nine cases of gastric carcinoma with excessive production of alpha-fetoprotein (AFP) were analyzed morphologically, histochemically and biochemically. Consequently, it was proposed that AFP-producing gastric carcinomas should be divided into three subtypes: (i) hepatoid type; (ii) yolk sac tumor-like type; and (iii) fetal gastrointestinal type. The data from the study suggested that the hepatoid type and the yolk sac tumor-like type are derived from liver cell metaplasia and yolk sac cell metaplasia of common poorly differentiated medullary adenocarcinoma, respectively. The fetal gastrointestinal type seemed to be a result of the imitation of fetal gastrointestinal epithelium by common tubular adenocarcinoma. The hepatoid type was also the most common in the file of AFP-producing gastric carcinoma. Unfortunately, most of the hepatoid types seemed to be highly malignant.

A giant tumor of the mesocolon found to be metastasis from an alpha-fetoprotein-producing gastric carcinoma: report of a case

We present herein an extremely rare case of metastasis from a gastric carcinoma to the mesocolon. A 71-year-old woman underwent a laparotomy for gastric cancer with an intra-abdominal mass. Her serum alpha-fetoprotein level was very high at 3,560 ng/ml. The abdominal mass was subsequently revealed to be a metastatic tumor of the transverse mesocolon derived from an alpha-fetoprotein-producing gastric carcinoma, but no other metastatic focus was found. An immunohistochemical study revealed alpha-fetoprotein-positive cells in both lesions. The serum alpha-fetoprotein level became normal after the operation which was followed by a course of chemotherapy, and no recurrence has been observed thus far in 6 months of follow up.

Hepatoid adenocarcinoma of the stomach. A clinicopathologic and immunohistochemical analysis

BACKGROUND

The clinicopathologic and immunohistochemical features of the primary gastric hepatoid adenocarcinomas still remain unclear.

METHODS

The authors evaluated 28 hepatoid adenocarcinomas (HC) of the stomach on the basis of characteristic histologic features resembling hepatocellular carcinoma, which were selected from the 7200 cases of primary gastric carcinoma in their files. Additionally, 22 alpha-fetoprotein (AFP)-positive adenocarcinomas without hepatoid features (APC) were also selected.

RESULTS

The HC cases fell into the following two groups: HC with AFP-positive tumor cells (Group 1; 15 cases) and HC without AFP-positive cells (Group 2; 13 cases). Histologically, the glycogen granules and hyaline globules were common features in HC. The incidence of a venous invasion of HC (Groups 1 and 2) was higher than that of APC (Group 3). There were no significant differences among the three groups regarding clinical features, macroscopic features, and the incidence of lymphatic permeation. An immunohistochemical study showed that HC had differentiation into various directions. As for the advanced carcinomas, the 5-year survival rates of patients with HC (Groups 1 and 2) and those with APC (Group 3) were 11.9% (21.4%, 8.3%) and 38.2%, respectively. The prognosis of Group 1 was similar to that of Group 2, but was poorer than that of Group 3.

CONCLUSIONS

The findings suggested that HC, as shown by its characteristic histologic features, had a poor prognosis whether producing AFP or not, and that HC should therefore be distinguished from AFP-positive carcinoma without hepatoid features.

Hepatoid carcinoma of the stomach

A patient with primary gastric carcinoma exhibiting hepatoid differentiation is described. The tumor itself was not associated with a high serum alpha-fetoprotein, but the cells stained positive for alpha-fetoprotein and alpha-1 antitrypsin. The patient underwent a total gastrectomy and wedge excision of the liver metastasis. The presence of metastatic hepatoid adenocarcinoma of the stomach should be considered in a patient who, during surgery for a primary gastric carcinoma, is found to have a liver metastasis that is diagnosed by frozen-section biopsy as a hepatoma. Because of lymph node and liver metastasis, prognosis appears to be poor for such patients.