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

Optimal treatment strategies for hepatoid adenocarcinoma of the lung: insights from a comprehensive analysis

BACKGROUND

Hepatoid adenocarcinoma of the lung (HAL) is a distinctly uncommon subtype of lung adenocarcinoma (LAC), characterized by hepatoid features and an alarmingly low 5-year survival rate of approximately 8%. The scarcity of information on this condition has contributed to the absence of standardized treatment protocols, and the molecular underpinnings of its pathogenesis remain largely unexplored. To bridge these gaps, this study compiled data from 191 primary HAL patients to delineate treatment patterns, prognostic factors, and potential pathogenic mechanisms.

METHODS

This study was divided into two cohorts: cohort 1, comprising 110 patients extracted from the Surveillance, Epidemiology, and End Results (SEER) database, and cohort 2, consisting of 70 patients identified through a comprehensive literature review via the PubMed, Web of Science, and Scopus databases, in addition to 11 patients from Tongji Hospital. The Cox proportional hazards regression model was employed to identify independent prognostic factors. Kaplan-Meier survival curves were generated to assess the impact of treatment modalities centered around surgery and chemotherapy. Moreover, this study evaluated the efficacy of first-line treatment regimens and conducted Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses on identified mutated genes.

RESULTS

The demographic and clinical profile of HAL patients typically comprises older individuals who are smokers, with a predisposition for diagnosis at advanced disease stages, culminating in a high mortality rate. Key prognostic indicators identified included disease stage, chemotherapy and surgical interventions. The study suggests a treatment strategy that advocates chemotherapy for patients with stage IV HAL and surgery for those with non-stage IV disease. The combination of paclitaxel and platinum-based chemotherapy emerged as an efficacious first-line treatment, with the integration of immunotherapy and targeted therapies showing potential benefits. Genetic analysis underscored similarities between HAL and LAC, particularly highlighting aberrant kinase activity (serine, threonine, and tyrosine) and the activation of PI3K-Akt and MAPK signaling pathways as contributing factors to HAL pathogenesis.

CONCLUSION

Despite its relatively rare occurrence, this study underscores the significance of treatment strategies and concludes probable prognostic factors. Due to limited reports, a deeper understanding of the molecular mechanisms driving tumorigenesis and progression in HAL is needed.

Primary Peritoneal Hepatoid Adenocarcinoma Patients Treated by Complete Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC)

Hepatoid adenocarcinoma (HAC) is an extremely rare disease, which could develop from any thoraco-abdominal organ and which exhibits features mimicking hepatocellular carcinoma (HCC). Its diagnosis is thus highly challenging, so is the treatment of that disease. So far, 12 cases have been reported in the literature as issued from the peritoneum. These primary peritoneal HAC were associated with a dismal prognosis and heterogenous management. Two additional cases were described here, managed in a multidisciplinary way as rare peritoneal surface malignancies in an expert center, following the strategy based on a comprehensive tumor burden extension assessment and a radical approach combining iterative complete cytoreductive surgeries followed by hyperthermic intra-peritoneal chemotherapy (HIPEC) and limited systemic chemotherapy sequences. In particular, the choline PET-CT scan guided surgical exploration to reach a complete resection. The oncologic outcomes were promising with a first patient dying 111 months after the diagnosis and a second patient still alive at 43 months.

Primary Hepatoid Adenocarcinoma of the Lung: A Systematic Literature Review

Background

Hepatoid adenocarcinoma (HAC) of the lung (HAL) is a rare and aggressive extrahepatic adenocarcinoma with an unknown etiology and unfavorable prognosis, which is similar to the pathophysiological characteristics of hepatocellular carcinoma (HCC).

Methods

We first presented a 67-year-old patient diagnosed with HAC in the right middle lobe of the lung. Then, a systematic literature search was performed for HAL cases recorded between 1990 and 2020 based on three databases. The clinicopathological features, therapeutic method, and prognosis of this rare disease were reviewed, and corresponding prognostic factors were explored using Kaplan–Meier (K-M) curve and Cox proportional hazards regression model. Additionally, the potential biological mechanisms of HAL were further explored and compared with HCC and lung adenocarcinoma (LUAD) based on online databases.

Results

In the present study, we reported an HAL patient who underwent surgical resection combined with chemotherapy and succumbed to disease 13 months after surgery. Additionally, a total of 43 experimental studies with 49 HAL patients, including the present case, met the inclusion criteria and were included in the present review. We found that HAL is characterized by a male-dominated incidence and is more common in the right lung. Patients in the surgical subgroup have a better prognosis than those in the non-surgical subgroup (p = 0.034). Moreover, the Cox proportional hazards regression model demonstrated that surgical resection can significantly improve the prognosis of HAL patients (p = 0.016). HAL is a rare disease associated with gene mutations that has a distinctive cause and unique pathogenesis. Additionally, Afatinib and Gefitinib may be new effective agents to better combat HAL.

Conclusion

In conclusion, males may exhibit an increased risk of developing HAL and poorer prognosis than females. Surgical resection combined with chemotherapy may prolong the survival of patients with HAL. HAL has its unique clinicopathological characteristics and biological mechanisms.

Clinicopathological features and genomic profiles of hepatoid adenocarcinoma of the lung: Report of four cases

OBJECTIVE

Pathological features of hepatoid adenocarcinoma of the lung (HAL) are similar to those of hepatocellular carcinoma (HCC) and HAL has a poor prognosis. In this study, we aimed to elucidate clinicopathologic and molecular features of HAL.

METHODS

Four cases of HAL patients with one lobe of the lung resected were enrolled into the study. Next generation sequencing (NGS) of a 425-gene panel was performed on tumor tissue samples.

RESULTS

The most frequently mutated gene was TP53 in three cases of primary HAL and one case of metastatic HAL, with a mutation rate of 100%. Also, CDK8, CDKN2A, EPHA5, SMARCA4, and STK11 were detected as high-frequency mutations, with a mutation rate of 50%. The types of TP53 mutation included two missense variants and two frameshift ones. The TP53 mutation was related to the occurrence of HAL.

CONCLUSION

HAL could be caused by genetic mutations and is closely related to TP53 mutation.

Clinical characteristics of Hepatoid adenocarcinoma of the lung: Four case reports and literature review

PURPOSE

Hepatoid adenocarcinoma of the lung (HAL) is a rare form of lung cancer, which is characterized by its morphologic hepatoid features. The clinical characteristics and prognosis of this rare form of lung cancer remain obscure.

METHODS

The clinical courses of four cases of HAL were reported. A literature search was performed up to December 31, 2020, using the electronic databases PubMed and Web of Science.

RESULTS

Including the present 4 cases, a total of 42 cases of HAL have been reported in the literature. The median age was 58.5 years old (range, 36-73 years). 36 (85.7%) patients were male. 26 (61.9%) patients had a history of smoking, the median amount of smoking was 40 pack years (range, 8-180). The most common site of the primary tumor was the right upper lobe (22 cases, 52.3%) and the left upper lobe (10 cases, 23.8%). 21 patients (50%) had pretreatment serum AFP levels higher than the upper limit, and 4 patients (9.5%) had normal pretreatment serum AFP levels. Treatment of HAL included surgery, chemotherapy, radiotherapy, tyrosine kinase inhibitors (TKIs), anti-angiogenesis therapy, and anti-PD-1/PD-L1 monoclonal antibody. Overall, the prognosis of HAL was poor, with median overall survival (OS) of 14 months.

CONCLUSIONS

HAL is an aggressive tumor, with a poor prognosis and male predominance, which tends to occur in heavy smokers and affects the right upper lobe of the lung.

Hepatoid Adenocarcinoma of the Lung: A Systematic Review of the Literature From 1981 to 2020

Objectives

We report the first case of hepatoid adenocarcinoma of the lung (HAL) with PIK3CA mutation. In addition, we analyzed data from HAL cases over the past 40 years to study its main treatment methods, prognosis, and the relationship between prognosis and the serum alpha-fetoprotein (AFP) level before treatment.

Methods

We report a 66-year-old male case who was diagnosed with locally advanced HAL with PIK3CA mutation and carried out a systematic literature search for HAL cases documented between 1981 and 2020. General patient information including case characteristics was extracted and summarized. The median OS (mOS) of HAL patients was determined using the KM survival curve. The Cox proportional hazards regression model was used to evaluate the effect of tumor size, location, and serum AFP value before treatment and radical surgery (RS) on the prognosis of patients.

Results

A total of 46 studies including 51 HAL patients was included in our review. Our study revealed that 52.9% of tumors were located in the upper lobe of the right lung. The proportion of serum AFP-positive patients before treatment, early-stage patients (TNM stage I and II), and patients who had received surgery were 69.2%, 34.1%, and 40%, respectively. The mOS of HAL patients was 16.0 months. The 2-year and 5-year survival rates of the patients were 35.3% and 8.0%, respectively. In the subgroup analysis, the 2-year survival rate for patients who received RS was 62.5%, while for patients who were unable to undergo RS, it was only 12.5% (p = 0.009). The Cox proportional hazards regression model indicated that RS can significantly improve the prognosis of HAL patients (p = 0.011), although the location and size of tumor as well as the serum AFP value before treatment had no significant effect on their prognosis (p = 0.82, p = 0.96, p = 0.25).

Conclusions

HAL patients have a poor prognosis, and the survival benefits for patients receiving chemoradiotherapy or chemotherapy alone appear to be limited. We demonstrate statistically for the first time that pretreatment serum AFP values are not related to the prognosis of HAL patients and RS can significantly improve patient prognosis.

Carcinosarcoma of the stomach with alpha-fetoprotein-producing hepatoid adenocarcinoma: an unexpected combination of two rare subtypes of gastric cancer in one tumor

Carcinosarcoma is a rare malignant neoplasm comprising both epithelial and mesenchymal components. Hepatoid adenocarcinoma (HAC) is another rare type of cancer. To date, there are only four reported cases of concurrent carcinosarcomas with HAC across all tumor types, all of which were observed in uterine tumors. Here, we report an unusual case of gastric carcinosarcoma associated with alpha-fetoprotein (AFP)-producing HAC in a 76-year-old woman. Upon admission, the patient had an elevated serum AFP concentration (448 µg/L), a necrotic polypoid tumor of the central gastric cardia revealed by endoscopy, and no evidence of distant metastasis indicated by computed tomography (CT). Owing to malignancy indicated by biopsy, the patient underwent proximal subtotal gastrectomy. The resected tumor was composed of both an HAC component and a sarcoma component, microscopically. The sample was positive for AFP, hepatocyte paraffin (Hep-Par) 1, glypican-3, SALL4, CDX2, cytokeratin (CK) (pan), CK18, desmin, and vimentin staining immunohistochemically. In summary, the tumor was diagnosed as carcinosarcoma of the stomach with AFP-producing HAC. To our knowledge, this is the first report of gastric carcinosarcoma with AFP-producing HAC in the English literature describing gastric tumors.

Hepatoid adenocarcinoma of the lung: An analysis of the Surveillance, Epidemiology, and End Results (SEER) database

Hepatoid adenocarcinoma of the lung (HAL) is a rare malignant tumor that is defined as a primary alpha-fetoprotein (AFP)-producing lung carcinoma. We aimed to identify prognostic factors associated with the survival of patients with HAL using data from the Surveillance, Epidemiology, and End Results (SEER) database. We collected data from patients diagnosed with HAL, adenocarcinoma (ADC), and squamous cell carcinoma (SCC) of the lung between 1975 and 2016 from the SEER database. The clinical features of patients with ADC and SCC of the lung were also analyzed. The clinical features of HALs were compared to ADCs and SCCs. A chi-square test was used to calculate the correlations between categorical variables, and a t test or Mann-Whitney U test was used for continuous variables. The Kaplan-Meier method and Cox regression analysis were used to identify the prognostic factors for the overall survival (OS) of HALs. Two-tailed p values < 0.05 were considered statistically significant. Sixty-five patients with HAL, 2,84,379 patients with ADC, and 1,86,494 with SCC were identified from the SEER database. Fewer males, advanced stages, and more chemotherapy-treated HALs were found. Compared to patients with SCC, patients with HAL were less likely to be male, more likely to be in an advanced stage, and more likely to receive chemotherapy (p < 0.05). The American Joint Committee on Cancer staging was the only prognostic factor for OS in patients with HAL, and stage IV was significantly different from other stages (hazard ratio = 0.045, 95% confidence interval: 0.005-0.398, p = 0.005). Males with HAL were more likely to receive radiotherapy compared to females with HAL (61.8 vs 31.5%, p = 0.034). Younger patients with HAL were more likely to receive chemotherapy (59.4 + 10.2 years vs 69 + 11.3 years, p = 0.001). The primary tumor size of HAL was associated with the location of the primary lesion (p = 0.012). No conventional antitumor therapies, including surgery, chemotherapy, and radiotherapy, were shown to have a significant survival benefit in patients with HAL (p > 0.05). This study showed that stage IV was the only prognostic factor for OS in HALs compared to other clinicopathologic factors. Conventional antitumor therapies failed to show survival benefit; thus, a more effective method by which to treat HAL is needed. Interestingly, the clinical features and the location of the primary lesion were shown to be associated with primary tumor size and treatment in patients with HAL, which have not been reported before.

Anti-PD-1 Therapy Achieved Disease Control After Multiline Chemotherapy in Unresectable KRAS-Positive Hepatoid Lung Adenocarcinoma: A Case Report and Literature Review

Hepatoid adenocarcinoma of the lung (HAL) is extremely rare and standardized treatment strategy for HAL has not been established. Patients with unresectable HAL have a shorter survival time ranges from 1 to 36 months. Here, we reported a 65-year-old female patient with unresectable alpha-fetoprotein-producing HAL harboring KRAS-G12V and no other targetable driver mutations. The patient was treated with multiple lines of chemotherapies followed by PD-1 inhibitor, sintilimab, due to positive staining of PD-L1, and achieved an overall survival of 52 months. Although the disease was under control, the patient experienced fifth-grade pneumonia and died after 6 months of anti-PD-1 treatment. This is the first case of KRAS-positive HAL patient achieved stable disease by PD-1 inhibitor, which may provide valuable information for the treatment strategy development of advanced HAL patients, and highlights the importance of molecular diagnosis in treatment decision-making.

Hepatoid adenocarcinoma of the lung mimicking metastatic hepatocellular carcinoma

Hepatoid adenocarcinoma of the lung is a rare subtype of lung cancer. We report a case of a metastatic hepatoid adenocarcinoma of the lung with aggressive behavior, including biopsy and autopsy findings. The pulmonary tumors showed features indistinguishable from hepatocellular carcinoma and were diffusely positive for Hepatocyte Paraffin 1.

Hepatoid adenocarcinoma of the lung and the review of the literature

INTRODUCTION

Hepatoid adenocarcinoma of the lung is an extremely rare type of the non-small cell lung cancer. Treatment principles and prognosis are similar to that of lung adenocarcinoma.

CASE REPORT

A 62-year-old female smoker presented with a huge mass in the left upper lobe. After diagnostic biopsy, she underwent left pneumonectomy and mediastinal lymph node dissection. A diagnosis of stage T4N1M0 hepatoid adenocarcinoma of the lung with positive surgical margins was made.

MANAGEMENT AND OUTCOME

After the operation, the level of serum alpha fetoprotein was 9010 ng/ml (N: <10). The level of serum alpha fetoprotein was decreased with concurrent chemoradiotherapy and chemotherapy. Disease progression was detected at 11 months after diagnosis. No response was obtained to other therapies. The patient died at 14 months from the time of diagnosis.

DISCUSSION

Usually, patients with hepatoid adenocarcinoma of the lung are male smokers. Hepatoid adenocarcinoma tends to settle in the upper lobes of the lung. The most important prognostic factor of the hepatoid adenocarcinoma of the lung is the disease stage at the diagnosis and patients with metastatic disease have poor survival.

A 60-Year-Old Man With Right Lung Mass Presents With Cough

CASE PRESENTATION

A 60-year-old Chinese man was admitted to our hospital with chronic cough for > 2 months. His cough was paroxysmal and nonirritating, occasionally productive with some small amounts of white phlegm. He had had a low-grade fever for half a month. There were no night sweats, joint swelling on limbs, pain, rash, or any other discomfort. The patient denied weight loss and decreased appetite.

Primary hepatoid adenocarcinoma of the lung in Yungui Plateau, China: A case report

BACKGROUND

Hepatoid adenocarcinoma (HAC) occurs in extrahepatic organs such as the gastrointestinal tract, testes, ovaries, lungs, mediastinum and pancreas, and frequently produces α-fetoprotein (AFP). HAC of the lung (HAL) is rare, characterized by difficult treatment and poor prognosis. There are no reports of HAL in Yunnan-Guizhou Plateau, China.

CASE SUMMARY

A 60-year-old male patient was clinically diagnosed with HAL pT3N0M0, stage IIB. Chest computed tomography revealed a 7.5 cm × 7.2 cm soft tissue mass located in the right lung upper lobe and the adjacent superior mediastinum. Right upper lobectomy was performed. The diagnosis of HAL was confirmed by pathological examination, and the patient received paclitaxel and carboplatin as adjuvant chemotherapy after surgery.

CONCLUSION

Clinical manifestations, pathological features, imaging findings, auxiliary examination, and treatment planning of HAL are presented to help clinicians improve their diagnosis and treatment.

Primary pulmonary hepatoid adenocarcinoma: A case report and review of the literature

RATIONALE

Hepatoid adenocarcinoma of lung (HAL) is a rare malignant tumor, which can be defined as a primary alpha-fetoprotein (AFP)-producing lung carcinoma. The majority of hepatoid adenocarcinoma (HAC) expressed AFP in tumor cells, but AFP expression is not required for its diagnosis according to the modified diagnostic criteria. Despite that HAC exhibits a poor prognosis and ineffective treatment options, early diagnosis and aggressive treatment can result in long-term survival.

PATIENT CONCERNS

We report a 70-year-old Chinese male patient with alcoholic intake over 30 years and smoking history of 60 cigarettes per day for 40 years. He sought medical consultation for productive cough and hemoptysis sputum.

DIAGNOSES AND INTERVENTIONS

Chest CT scan revealed a mass (6.4 × 5.5 cm) in the left lower lobe of the lung. The patient underwent curative surgical resection, and subsequently diagnosed as HAL.

OUTCOMES

Eighteen months after primary diagnosis, the patient died of multiple organ failure caused by distant metastases.

LESSONS

Familiarizing with the clinical features and modified diagnostic criteria of this rare tumor may increase awareness of the disease among clinicians and pathologists, thereby avoiding misdiagnosis and mistreatment.

Synchronous Presentation of Hepatoid Alpha-Fetoprotein-Producing Lung Cancer and Colorectal Adenocarcinoma

We describe the synchronous presentation of hepatoid adenocarcinoma of the lung and colorectal adenocarcinoma in a patient with elevated alpha-fetoprotein (AFP) serum levels. Our patient was treated after surgery with a conventional chemotherapy regimen including bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, which was demonstrated to improve the clinical results in the treatment of colorectal and lung cancer compared with chemotherapy alone, and is today approved both for colon and lung cancer.

Besides the unconventional association of the two cancer types in our patient and the unsatisfactory clinical benefit obtained with the medical treatment administered, we report on the significance of AFP serum levels as a tumor marker in this peculiar situation. In our patient these levels, monitored from the first clinical symptoms through the last chemotherapy course, did not show any correlation with the response to treatment or with the patient's overall outcome. In particular, the serum marker remained essentially unchanged after the surgical removal of the lung mass and the subsequent chemotherapy.

Hepatoid Adenocarcinoma of the Urachus

Hepatoid adenocarcinoma of the urachus is a rare condition. We present the case of a 51-year-old female who developed abdominal pain and hematuria. Pelvic magnetic resonance imaging (MRI) reported an urachal mass with invasion to the bladder that was resected by partial cystectomy. On light microscopy the tumor resembled liver architecture, with polygonal atypical cells in nest formation and trabecular structures. Immunochemistry was positive for alfa-fetoprotein (AFP) and serum AFP was elevated. Hepatoid adenocarcinomas have been reported in multiple organs, being most commonly found in the stomach and the ovaries. Bladder compromise has been rarely described in the literature, and it has been associated with poor prognosis, low remission rates, and early metastasis.

Hepatoid adenocarcinoma of the lung: Review of a rare form of lung cancer

RATIONALE

Hepatoid adenocarcinoma (HAC) is a rare malignant lung tumor that histologically resembles typical hepatocellular carcinoma (HCC) when it is metastatic to the lung. To date, this clinical entity has not been highlighted in the pulmonary literature.

OBJECTIVE

We present a review of all known cases of HAC, including the relevant clinical and histopathological features important for pulmonologists.

MEASUREMENTS AND MAIN RESULTS

The purpose of this report is to present a new case of HAC, with typical clinical and histologic features of this malignancy, and to summarize findings of previously reported cases. A systematic literature search of the electronic database PUBMED was conducted to identify all cases of hepatoid adenocarcinoma reported in the English literature, between January 1980 and June 2015. HAC and HCC can be distinguished by immunohistochemical staining. HAC usually presents as a large bulky solitary mass in the upper lobe; there is an exceedingly high prevalence in males and most patients with this tumor are smokers. Serum alpha-fetoprotein (AFP) in very high levels has been a distinguishing feature of this tumor. Nodal and distant metastases are common at initial presentation and, as a result, the prognosis is very poor. Resection and long-term survival, however, have been reported.

CONCLUSION

Hepatoid adenocarcinoma, first described as a gastric tumor, has also been described in the lung. It morphologically resembles and must be distinguished from metastatic HCC of the lung. While most tumors produce AFP, the case we present demonstrates that this should not be a criterion for diagnosis.

A Primary Pure Yolk Sac Tumor of the Lung Exhibiting CDX-2 Immunoreactivity and Increased Serum Levels of Alkaline Phosphatase Intestinal Isoenzyme

Malignant extragonadal germ cell tumors primary to the lung are quite uncommon lesions, but pure yolk sac tumor is even more exceptional. This is believed to be the first reported case of yolk sac tumor of the lung in which an intense and diffuse immunoreactivity for CDX2, a marker of intestinal differentiation reportedly expressed also in gonadal yolk sac tumor, was associated with increased serum levels of the alkaline phosphatase intestinal isoform. Nine months after radical surgery and adjuvant chemotherapy, the patient is alive and well without evidence of recurrent or metastatic disease and with serum levels of the alkaline phosphatase intestinal isoform within normal limits. The pathologist should be aware of yolk sac tumor arising in the lung and that alkaline phosphatase intestinal isoform could become an additional serum marker for such a tumor.

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.

Hepatoid adenocarcinoma of the lung without production of α-fetoprotein: A case report and review of the literature

Hepatoid adenocarcinoma of the lung (HAL) is a rare type of extrahepatic hepatoid adenocarcinoma. The majority of such cases that have been reported in the English literature have demonstrated elevated serum α-fetoprotein (AFP) and/or positive AFP expression on histopathological analysis, and have had poor prognoses. The current study reports an extremely rare case of HAL in the right upper lung without AFP production in a 59-year-old male patient. The patient underwent radical right upper lobectomy via video assisted thoracoscopic surgery. No signs of local recurrence or distant metastasis have been observed for 23 months after the surgery. The serum AFP level following surgery remained within the normal range. Although the diagnosis of HAL predominantly depends on pathological examination, a review of the literature demonstrates that HAL has certain characteristic features with regard to its clinical and computed tomography findings and prognoses, and clinicians should be aware that clinicians should be aware that monitoring serum AFP levels, as well as CT findings, remains important.

Pulmonary hepatoid adenocarcinoma: report of a case

Hepatoid adenocarcinoma (HAC) is a rare neoplasm with aberrant hepatocellular differentiation. HAC occurs in extrahepatic organs such as the gastrointestinal tract, testes, ovaries, and lungs and frequently produces alpha-fetoprotein. A 69-year-old patient was diagnosed clinically with T2aN0M0, stage IB, non-small cell lung carcinoma. Because the tumor showed tight adhesion to the chest wall, we performed left upper lobectomy, combined resection of the 3rd and 4th ribs, and lymph node dissection. Pathological examination confirmed the diagnosis of HAC of the lung (pathological T2aN0M0, stage IB), and four courses of cisplatin and gemcitabine were administered as adjuvant chemotherapy. Genetic analysis of the epidermal growth factor receptor showed wild type. Preoperative serum alpha-fetoprotein level, a useful marker of disease progression, was elevated to 4497 ng/ml, decreasing within the normal range by about 3 months postoperatively. The patient remains alive without recurrence as of 51 months after surgery.

Hepatoid adenocarcinoma of the lung: Presenting mediastinal metastasis without transfer to the liver

Hepatoid adenocarcinoma of the lung (HAL) is a rare type of lung cancer. Its diagnosis and treatment may be difficult due to the varied presentation; however, immunohistochemical analysis facilitates the diagnosis. The present study presents a case of HAL. The patient was a 48-year-old male who presented with a primary complaint of back pain. A chest computed-tomography scan revealed a lobulated soft-tissue mass that extended from the left lung apex to the middle and posterior mediastinum. The area of the largest cross-section was 7.9×10.0 cm and the lymph nodes did not demonstrate metastasis. Immunohistochemical staining of a transbronchial lung biopsy revealed that the tumor cells were α-fetoprotein (AFP)(positive) and hepatocytes(positive) and a diagnosis of hepatoid carcinoma of the left lung was established. The level of serum AFP, a tumor marker, was elevated (6,283 ng/ml). The patient presented with mediastinal metastases and was classified as stage IIIA (N2); following diagnosis, the patient received concurrent chemoradiation. Subsequent to chemoradiation, the left lung lump with the largest cross-section was 3.3×4.2 cm and the serum AFP had fallen to its lowest level (23.11 ng/ml). However, when the patient relapsed, the serum AFP level elevated markedly (57,800 ng/ml). Furthermore, the nodules of metastasis increased in number and enlarged, with the largest measuring 2.1 cm. The patient succumbed as a result of a lung infection.

Hepatoid adenocarcinoma of the lung: report of five cases and review of the literature

The current diagnostic criteria for hepatoid adenocarcinoma of lung include typical acinar or papillary adenocarcinoma and a component resembling hepatocellular carcinoma and expressing α-fetoprotein (AFP). Distinguishing hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung is difficult in patients with both lung and liver masses and in patients at risk for lung and liver cancer because of smoking and viral hepatitis, respectively. We studied morphologic features of hepatoid adenocarcinoma of lung and established an immunohistochemical panel to facilitate distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung. Five cases of hepatoid adenocarcinoma of lung were stained with hematoxylin and eosin and mucicarmine for histomorphologic evaluation. The 14-marker immunohistochemical profile was established for hepatoid adenocarcinoma of lung and compared with that of hepatocellular carcinoma. Two cases of hepatoid adenocarcinoma of lung had signet-ring cell components. Three cases were pure hepatoid adenocarcinoma without components of acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. Like hepatocellular carcinoma, hepatoid adenocarcinoma of lung expresses CK8 (5/5), CK18 (5/5), AFP (3/5) and HepPar1 (5/5), shows cytoplasmic staining with TTF-1 (5/5) and does not express CK14 (0/5). Unlike hepatocellular carcinoma, it expresses CK5/6 (1/5), CK7 (3/5), CK19 (4/5), CK20 (1/5), HEA125 (5/5), MOC31 (5/5), monoclonal CEA (3/5) and napsin A (1/5). An immunohistochemical panel that includes a variety of cytokeratins, monoclonal CEA and EpCAM markers (HEA125 and MOC31) facilitates distinction of hepatoid adenocarcinoma of lung from hepatocellular carcinoma metastatic to lung, especially when correlated with clinical and radiologic findings. We propose modification of the current diagnostic criteria for hepatoid adenocarcinoma of lung. Tumor composition can be either pure hepatoid adenocarcinoma or hepatoid adenocarcinoma with components of typical acinar or papillary adenocarcinoma, signet-ring cells or neuroendocrine carcinoma. AFP expression is not requisite for diagnosis as long as other markers of hepatic differentiation are expressed.

Establishment and biological characterization of a novel cell line derived from hepatoid adenocarcinoma originated at the ampulla of Vater

Hepatoid adenocarcinoma is a rare gastrointestinal tumor and mostly reported in the stomach. Effective chemotherapy has yet to be developed to improve poor prognosis. The present study was undertaken to establish a useful cell line derived from a hepatoid adenocarcinoma, possibly leading to a new therapeutic strategy. The new human cell line VAT-39 was established from a metastatic lymph node of a 69-year-old Japanese male patient with hepatoid adenocarcinoma of the ampulla of Vater. The primary tumor and metastatic lymph node were composed of hepatoid adenocarcinoma cells exhibiting immunohistochemical reactivity for alpha-fetoprotein (AFP) and glypican-3 (GPC3). In the metastatic lymph node, Periodic acid-Schiff (PAS) staining clarified diffuse deposition of glycogen in the cytoplasm, indicating analogous characteristics to the primary hepatoid adenocarcinoma. Moreover, VAT-39 cells produced high levels of AFP in the cultured medium, and reverse-transcriptase polymerase chain reaction (RT-PCR) verified increased expression of GPC3 mRNA in this cell line. Further, we evaluated the sensitivity to major chemotherapeutic drugs against the bile duct cancer. Neither 5-fluorouracil nor gemcitabine showed particular sensitivity to this cell line. The tumorigenicity of the cultured cells was confirmed in athymic nude mice and the histological features of the explanted tumor were similar to the VAT-39 cell line. The present VAT-39 is the first hepatoid adenocarcinoma cell line that originates from the ampulla of Vater and it will be applicable for basic biological studies searching for new strategies of molecular targeted chemotherapy to this disease.

High-grade lung adenocarcinoma with fetal lung-like morphology: clinicopathologic, immunohistochemical, and molecular analyses of 17 cases

Low-grade lung adenocarcinoma of fetal lung type, which is well characterized by its unique clinicopathologic and molecular features, is recognized as a distinct variant of lung cancer. In contrast, high-grade lung adenocarcinoma with fetal lung-like morphology (HG-LAFM) has not been studied widely. To characterize this subset better, we analyzed 17 high-grade adenocarcinomas with at least focal component resembling a developing epithelium in the pseudoglandular phase of the fetal lung. These rare (ca. 0.4%) carcinomas occurred predominantly in elderly men with a heavy smoking history, who showed elevated serum α-fetoprotein in 4 of 5 cases tested. Histologic examination revealed a fetal lung-like component as a focal finding accounting for 5% to 60% of the total tumor volume. It was invariably admixed with tissues having a morphology not resembling that of a fetal lung. A coexisting non-fetal lung-like element was quite heterogenous in appearance, showing various growth patterns. However, clear-cell (88%), hepatoid (29%), and large cell neuroendocrine carcinoma (24%) histology seemed overrepresented. HG-LAFM was characterized immunohistochemically by frequent expression of α-fetoprotein (41%), glypican-3 (88%), SALL-4 (59%), neuroendocrine markers (82%), CDX-2 (35%), and p53 (65%). HG-LAFM was molecularly heterogenous in that EGFR or KRAS mutation was observed in 22% of cases tested for both. Our data indicate that HG-LAFMs might form a coherent subgroup of lung adenocarcinomas. However, the uniformly focal nature of the fetal lung-like element, widely diverse coexisting non-fetal lung-like histology, and inhomogenous molecular profiles lead us to believe that HG-LAFM is best regarded as a morphologic pattern showing characteristic association with several clinicopathologic parameters rather than a specific tumor entity.

Hepatoid adenocarcinoma of the lung

Lung adenocarcinomas with a mixture of tubular or papillary pattern, sheet-like or trabecular architecture, eosinophilic cytoplasm with centrally located nuclei and alpha-fetoprotein-producing cells have been described as hepatoid adenocarcinomas. Hepatoid adenocarcinomas are mainly found in the stomach but rare cases in other organs have been described. Immunostaining for alpha-fetoprotein (AFP), hepatocyte paraffin 1 (HepPar-1) and thyroid transcription factor-1 (TTF-1) helps in the diagnostic workup. Tumor behavior is still not entirely known but it seems to be associated with early metastases. We report on a 66-year-old, heavy-smoker male patient who had a 10-month history of respiratory complaints and weight loss. At the time he was hospitalized, respiratory failure was already established. The computed tomography corresponded to a collapsed right lung due to a poorly defined expanding mass. The bronchoscopy revealed narrowing of the inferior and medium lobar bronchi. The patient developed irreversible shock and died. At the right lung inferior lobe was extensively replaced by a grayish diffuse neoplasia in a “pneumonia-like” gross pattern. Metastatic disease was found in the right adrenal gland and thoracic and abdominal lymph nodes. Microscopic dissemination through lymphatics, pleura, and airways was detected. Histological examination revealed a poorly differentiated adenocarcinoma with hepatoid features. Immunohistochemmistry stains were positive for keratin 7, polyclonal carcinoembryonic antigen (CEA) in a diffuse pattern, AFP and HepPar-1 antibody. TTF-1 showed a diffuse granular cytoplasmic staining of the neoplastic cells, and only focal nuclear positivity. Multiple bilateral emboli originated from deep venous thrombosis were present in large and medium branches of the pulmonary artery and contributed to the cause of death.

Hepatoid pancoast tumor. A case report and review of the literature

A 48-year-old male patient presented with a Pancoast tumor of the right lung and a serum alpha-fetoprotein (αFP) at 39,000 ng/ml. Alpha-fetoprotein is a tumor marker found elevated in patients with hepatocellular carcinoma (HCC), germ cell or stromal tumors of the ovary and nonseminomatous testicular cancer. Occasionally, this tumor marker may rise in non-neoplastic conditions such as cirrhosis and hepatitis and only exceptionally in rare cancers with hepatoid differentiation. We present our case report and review the English literature for αFP-producing lung carcinomas. To the best of our knowledge this is the first report in the literature of an αFP producing Pancoast tumor.

An analysis of clinicopathological features and prognosis by comparing hepatoid adenocarcinoma of the stomach with AFP-producing gastric cancer

OBJECTIVE

To investigate the differences between alpha-fetoprotein-producing gastric cancer (AFPPGC) and hepatoid adenocarcinoma of the stomach (HAS), and the clinicopathologic features and prognosis of HAS.

METHODS

From 1996 to 2007, there were 111 patients with elevated serum level of alpha-fetoprotein (AFP) preoperatively in Fudan University Shanghai Cancer Center. Primary lesions of 104 patients were stained positively for AFP. Among these patients, 45 patients were diagnosed as HAS. The clinicopathologic characteristics and prognostic factors of AFPPGC and HAS were analyzed. Additionally, 208 stage-matched AFP-negative gastric cancer patients were selected as control.

RESULTS

Immunohistochemically, the tumor cells were positive for AFP in AFPPGC. Histologically, the polygonal tumor cells were arranged in trabecular fashion or solid nests separated by narrow fibrous stroma composed of sinusoid-like capillaries in HAS. The survival rates of the three groups were statistically different (P < 0.01).

CONCLUSION

AFP-producing gastric cancer and HAS had more aggressive behavior than that of common gastric cancer. The prognosis of HAS was poorer than that of AFPPGC, therefore it should be distinguished from the latter.

Alpha-fetoprotein-producing primary lung carcinoma: a case report

Alpha-fetoprotein (AFP)-producing lung adenocarcinoma is a rare type of lung cancer, with its characteristics not yet fully clarified. We recently encountered a case of this type of lung cancer. The patient was a 69-year-old man who consulted an internist with the chief complaint of epigastric pain. Chest X-ray and CT revealed a lobulated mass measuring 70 mm in diameter in the right lower lung field and a metastasis in the right hilar lymph nodes. Of the tumor markers, the serum AFP was elevated (4620 ng/ml), and the serum carcinoembryonic antigen and carbohydrate antigen 19-9 were also slightly elevated. Transbronchial lung biopsy revealed the diagnosis of lung cancer. Under thoracoscopic assistance, right lower lobectomy + mediastinal lymph node dissection was carried out. Immunostaining showed the tumor cells to be AFP-positive. The tumor was thus diagnosed as an AFP-producing lung adenocarcinoma. The patient followed an uneventful clinical course after the surgery, with serum AFP decreasing to the normal range by about 2 weeks after the surgery. As of this writing, no sign of tumor recurrence has been noted. This case is presented here with a review of the literature.

Analysis of clinicopathologic features and prognostic factors in hepatoid adenocarcinoma of the stomach

OBJECTIVE

To investigate the different nature between hepatoid adenocarcinoma of the stomach (HAS) and common stomach cancer without the hepatoid differentiation areas (non-HAS).

METHODS

From January 1996 to December 2007, 45 patients were diagnosed as HAS on the basis of the characteristic histologic features resembling hepatocellular carcinoma in Fudan University Shanghai Cancer Center. The clinicopathologic features and the relevant prognosis of these patients were evaluated. In addition, 225 stage-matched common stomach cancer patients were selected as controls.

RESULTS

Histologically, the polygonal tumor cells were arranged in trabecular fashion or solid nests separated by narrow fibrous stroma composed of sinusoid-like capillaries. Immunohistochemically, the tumor cells were positive for α-fetoprotein. Under transmission electron microscope, numerous circular granules of dense electron were found in the cytoplasm. HAS showed a higher rate of vascular invasion, lymph node metastasis, and liver metastasis than non-HAS. The 5-years survival rates of HAS and non-HAS were 9% and 44%, respectively. The prognosis of HAS was poorer than that of non-HAS (P<0.05).

CONCLUSION

HAS had different clinicopathologic features and prognosis from non-HAS.

Soft-Tissue Localization of Hepatoid Adenocarcinoma: First Case Report

Hepatoid adenocarcinoma (HAC) is a rare type of extrahepatic cancer, whose pathologic features are indistinguishable from those of hepatocellular carcinoma. About thirty cases, nearly half of which occurring in the lung, have been described in patients with a normal liver. No imaging features are typical enough to allow a correct diagnosis. A localization of HAC in the soft tissues of the shoulder with invasion of the scapula in a woman without other symptoms is reported in this paper; soft-tissue HACs have never been described to date. An associate pulmonary HAC was eventually found in this patient.

Hepatoid carcinoma of the ovary with sex cord stromal tumor: a previously unrecognized association

BACKGROUND

Hepatoid carcinoma (HC) of ovary is a rare type of epithelial tumor composed mainly of epithelioid cells with abundant acidophilic cytoplasm, histologically indistinguishable from hepatocellular carcinoma. We report a previously unrecognized case of HC of ovary concurrent with a Sertoli cell tumor.

CASE REPORT

A 42-year-old woman patient with a long-term history of hepatitis C presented with a mass of left ovary without evidence of hepatic tumor. After initial diagnosis of primary ovarian carcinoma (FIGO Stage I), she had experienced a first recurrence in upper abdomen. Histologically, the primary tumor was composed of epithelioid cells with "hepatoid features" in association with a sex cord stromal tumor of Sertoli-type. Immunohistochemistry hepatoid cells stained positively for hepatocyte paraffin-1, alpha-fetoprotein and alpha-1 antitrypsin; moreover, Sertoli-type cells were positive for alpha-inhibin, calretinin and CD99. A final diagnosis of HC concurrent with Sertoli-type tumor was made.

CONCLUSION

The occurrence of this unreported association of HC with Sertoli-like tumor, the problems of differential diagnosis and therapeutic management of these tumors are the subject of this presentation. A diagnosis of ovarian metastasis from hepatocellular carcinoma is easy in patients with known primary tumor of liver and should be always excluded in these cases as an hepatoid variant of yolk sac tumor. Immunohistochemistry is not useful in these cases. However, a combination of clinical and pathological features is necessary for a correct diagnosis.

A case of *-fetoprotein-producing pulmonary carcinoma with restricted expression of hepatocyte nuclear factor-4* in hepatoid foci: a case report with studies of previous cases

We report a case of *-fetoprotein (AFP)-producing pulmonary carcinoma with studies for messenger RNA (mRNA) expression of hepatocyte nuclear factor (HNF)-4*, which is a transcription factor that is highly expressed in the process of liver development. The patient was a 64-year-old man with a pulmonary tumor in his left lower lobe. Serum AFP was 673 ng/mL. The microscopic analysis of the surgical specimen revealed a large cell neuroendocrine carcinoma with occasional hepatoid foci. The competitive reverse transcriptase polymerase chain reaction analysis revealed that HNF-4* mRNA was expressed on the order of 10(2)- to 10(3)-fold more abundantly than control pulmonary carcinomas and normal lung tissues. In addition, AFP and HNF-4* expression was restricted in hepatoid foci. Two previously reported cases of AFP-producing pulmonary carcinoma were also positive, whereas all 18 control pulmonary carcinomas were negative for HNF-4*. These findings suggest that aberrant expression of HNF-4* is implicated in the emergence or maintenance of hepatoid foci in AFP-producing pulmonary carcinomas.

Hepatoid adenocarcinoma of the gallbladder: Case report and review of the literature

A rare case of hepatoid adenocarcinoma (HAC) of the gallbladder occurred in a 72-year-old man who presented with abdominal pain and was admitted to hospital. Ultrasonography and computed tomography revealed a mass in the gallbladder, multiple nodules in the liver and enlargement of the lymph nodes. He was diagnosed as having a gallbladder carcinoma with multiple liver and lymph node metastases. Cholecystectomy and partial hepatectomy was performed. Histologically, most of the mass in the gallbladder was composed of cells with eosinophilic cyto-plasm arranged in a trabecular pattern, which resembled hepatocellular carcinoma, but there was a component of well-differentiated adenocarcinoma in the mucosa. Immunohistochemically these hepatoid tumor cells were positive for Hepatocyte (Hepatocyte Paraffin 1: Hep Par1), which is considered highly sensitive and highly specific for hepatocyte differentiation. Based on these findings, this case was diagnosed as hepatoid adenocarcinoma of the gallbladder, which is generally a vary rare neoplasm in the literature, but should be included in the differential diagnosis of a mass in the gallbladder.

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.

Hepatoid adenocarcinoma of the gallbladder: a mimicker of hepatocellular carcinoma

We present a case of a large gallbladder tumour in a patient with no known liver disease and elevated alpha-fetoprotein (AFP), in whom a differential diagnosis from hepatocellular carcinoma (HCC) in a non-cirrhotic liver was particularly difficult given the combination of the size of the tumour, solitary nature, elevated AFP and striking resemblance with HCC at histology. In presenting this patient, we would like to emphasise the role of MRI as a problem-solving tool for analysis of rare tumours of non-hepatocellular origin, including hepatoid adenocarcinoma of the gallbladder.

Primary hepatoid adenocarcinoma of the uterine cervix

Hepatoid adenocarcinoma is characterized histologically by neoplastic epithelial cells that resemble hepatocellular carcinoma (HCC) and produce alpha-fetoprotein (AFP). We describe a case of hepatoid adenocarcinoma of the uterus that, unlike any other previously reported case, was strictly confined to the cervix. A cervical biopsy demonstrated poorly differentiated adenocarcinoma, and hysterectomy and bilateral salpingo-oophorectomy were subsequently performed. Histologically, the lesion consisted of solid sheets of hepatoid cells accompanied with areas of endometroid adenocarcinoma. The tumor cells showed strong and diffuse cytoplasmic immunoreactivity with AFP in both medullary and adenocarcinoma components. Metastases to bilateral pelvic lymph nodes were detected 12 months after surgery. Since undergoing total pelvic irradiation, the patient has been alive and in full remission for 22 months. To our knowledge, this is the first report of primary hepatoid adenocarcinoma of the uterine cervix.

Hepatoid carcinoma colliding with a liposarcoma of the left colon serosa presenting as an abdominal mass

Background

Hepatoid adenocarcinoma (HAC) is a peculiar type of extrahepatic adenocarcinoma generally characterized by adenocarcinomatous and hepatocellular carcinoma (HCC)-like foci. Stomach is the most frequent site where hepatoid adenocarcinoma occurs, although it has been described in many other organs. On the other side, liposarcoma is a rare, malignant tumor that develops from fat cells.

Case presentation

We describe here a case of hepatoid carcinoma in collision with a liposarcoma of the left colon serosa in a 71-year-old man. It presented as an abdominal mass involving several organs, falsely mimicking metastatic colonic adenocarcinoma. Recognition of this entity was evident on microscopic evaluation following surgery. The patient had an objective response following liposomal antracycline chemotherapy, with a 3-year overall survival.

Conclusion

To our knowledge, this is the first case of a hepatoid tumor colliding with a liposarcoma of the left colon serosa reported to date.

Extragonadal germ cell tumors: a review with emphasis on pathologic features, clinical prognostic variables, and differential diagnostic considerations

Extragonadal germ cell tumors (GCTs) are relatively uncommon, but represent 1% to 5% of all GCTs. Their morphology varies widely and includes mature teratoma, immature teratoma, seminoma, yolk sac tumor, embryonal carcinoma, choriocarcinoma, and mixed GCTs. Noncentral nervous system extragonadal GCTs are found in a variety of anatomic locations, but most commonly affect the mediastinum and sacrococcygeal region. Predicting behavior in these tumors can be confusing because it is based on a combination of varying factors including patient age, histologic subtype, anatomic site, and clinical stage. This review attempts to dissect these issues by separating the discussion into 3 age groups: neonatal (congenital), children (prepubertal), and adult (postpubertal). Within each individual age group, we cover the significance of anatomic site, morphology, and staging parameters. In addition, we discuss the spectrum of associated secondary malignancies and their impact on patient outcome. Finally, we provide a detailed survey of differential diagnostic considerations grouped by anatomic site.

Preliminary study on the clinical and pathological relevance of gastric hepatoid adenocarcinoma

OBJECTIVE

To appraise the histological characteristics and clinical features of gastric hepatoid adenocarcinoma (GHAC) and their relevance with prognosis.

METHODS

From January 2001 to December 2003, six patients were diagnosed and confirmed pathologically in Ruijin Hospital as having a gastric hepatoid carcinoma. All these six patients, together with 30 randomly selected patients with gastric poorly differentiated adenocarcinoma (GPDA) and 30 with a primary hepatocellular carcinoma (HCC) who served as controls, were studied and analyzed clinically, histologically and immunohistologically.

RESULTS

The average age of the six patients with GHAC was 66.8 years, and their serum alpha fetoprotein (AFP) level was 84-2230 ng/mL. Of these six patients, two had a recurrence of cancer and two had liver metastasis. Their average survival period was 17 months. Morphologically, the histological appearance was similar to that of HCC, with glycogen granules and hyaline globules arranged in a solid or trabecular pattern and an abundance of blood vessels and sinusoids, while blood vessel or lymphatic invasion were more often seen. Immunohistological staining showed that the tumor cells were positive for AFP and negative for Hepatocyte paraffin 1 (HepPar1), and the tumor cells were separated by CD34-positive blood vessels into a small trabecular pattern. The GPDA had a solid nest or diffuse distribution pattern and was negative for both AFP and HepPar1. In the HCC, the histological feature was manifested as solid, small and large trabecular patterns with abundance of blood vessels and sinusoids; immunohistochemical staining showed the tumor cells were positive for HepPar1.

CONCLUSION

Serum AFP-positive GHAC occurred more frequently in older patients with higher rates of recurrence and liver metastasis and a poor prognosis. Histologically, GHAC was similar to HCC. The tumor cells that were positive for AFP but negative for HerPar1 could be used to differentiate with GPDA (both AFP and HerPar1 negative) and primary HCC (most AFP and HerPar1 positive).

Hepatoid Carcinoma With Serous Component of the Fallopian Tube

A very rare case of hepatoid carcinoma with serous component arising in the fallopian tube of a 79-year-old woman is presented. The lesion was a 5.0-cm unencapsulated, yellowish-white soft mass. The tumor was composed of hepatoid carcinoma (90%) and serous carcinoma (10%) components. The hepatoid carcinoma was histologically characterized by a proliferation of round to polygonal cells arranged in a trabecular, tubular, sinusoidal, papillary, or solid pattern. The serous component in the fallopian tube also showed in situ lesions. Both components showed an infiltration into the surface of the left ovary, omentum, peritoneum including the pouch of the Douglas, and serosa of the colon. Immunohistochemically, the hepatoid carcinoma was positive for alpha-fetoprotein, polyclonal carcinoembryonic antigen (CEA), hepatocyte paraffin 1, albumin, epithelial membrane antigen, and cytokeratin (CAM5.2). Ultrastructurally, the cytoplasm contained abundant ribosomes, moderate amounts of mitochondria, and rough endoplasmic reticulum that developed into a meshwork and contained mitochondria within it. Microbile channel-like structures and desmosomes were occasionally observed. The association with serous carcinoma indicates mullerian origin rather than germ cell origin. The patient received chemotherapy and was alive without disease at 10 months after surgery.

Hepatoid malignancy of unknown origin--a diagnostic conundrum: review of literature and case report of collision with adenocarcinoma

Hepatoid carcinomas are a group of neoplasms with features resembling hepatocellular carcinomas. Although rare, more cases have been noted to arise from various organs within the last decade. Differentiating these tumors is not only a challenge but also critical, since treatment modalities and operative strategies are dependent upon the exact nature of the hepatoid cancer. Based on a review of literature, we discuss the guidelines for differentiating these tumors and utilize these criteria to differentiate these tumors irrespective of their primary tissue of origin. We also describe an unusual case of hepatoid variant of primary peritoneal yolk sac tumor presenting with extensive carcinomatosis and as a collision with two synchronous primary colonic adenocarcinomas, neither of which has been reported to our knowledge to date, thereby falsely mimicking metastatic dedifferentiated colonic adenocarcinoma.

CASE DESCRIPTION

A septuagenarian female presented with weight loss, chronic anemia and ascites associated with bloating. Her past history was significant for COPD, hysterectomy and a bilateral oophorectomy 40 years previously. A work up which included computed tomography (CT) and contrast enema revealed significant ascites with multiple peritoneal nodules causing ascending colonic obstruction. Celiotomy revealed the entire peritoneal surface to be studded with nodules, with the largest measuring 6.0 cm. Intraoperative ultrasound, prompted by the frozen section of nodules resembling liver tissue, revealed no intrahepatic nodules. Right colectomy, omentectomy and tumor debulking were performed. The postoperative course was uneventful except for ascitic leak that spontaneously resolved.

DISCUSSION

The peritoneal nodules consisted of malignant cells arranged in cords that resembled liver tissue. In the absence of a primary identifiable liver disease, this is consistent with either hepatoid variant of primary yolk sac tumor or hepatoid carcinoma arising from the peritoneum. The right colectomy specimen revealed two mucosal ulcers consistent with colonic adenocarcinoma abutting two large tumor nodules on the serosal surface. Although grossly appearing to be contiguous, low power examination showed that the serosal nodule and the mucosal lesion were entirely different, and separated by a definite fibrous band. Immunohistochemical stains and patterns were used to differentiate the type of tumor. This article also discusses the criteria used to differentiate hepatoid yolk sac tumors (hepatoid-YSTs), hepatoid carcinomas and metastatic hepatocellular carcinomas and the phenomenon of opisthoplasia observed in certain malignancies. The difficulties encountered in identifying hepatoid carcinomas and current modalities used to differentiate these tumors are highlighted. The phenomenon of opisthoplasia and the challenges posed by this phenomenon in certain metastatic lesions are reviewed and explanations for the possible origins of hepatoid tumors are considered.

CONCLUSION

The most likely explanation in our case is that the hepatoid tumor either originated from microscopic remnant ovarian tissue left behind or primarily from the peritoneum. With no evidence of yolk sac component within the colonic tumor or in the draining lymphatics, this essentially excludes the commonly observed metastatic dedifferentiation (opisthoplasia) of adenocarcinoma to primitive forms (also known as combination tumors). Based on analysis of various factors, including tumor behavior and response to chemotherapy, we conclude that our case was a hepatoid variant of yolk sac tumor presenting in an elderly woman with carcinomatosis. This unusual presentation of two entirely different primary malignancies in close proximity is defined as "collision tumor". This is the first reported case of collision tumors involving dual colonic and primary peritoneal hepatoid-YST. Identifying the exact type still remains to be the most challenging aspect in the diagnosis of hepatoid tumors.

Hepatoid Thymic Carcinoma

We describe the clinicopathologic findings in a so far unrecognized thymic tumor. The tumor occurred in a 70-year-old woman with respiratory distress but neither myasthenia gravis nor other symptoms. Metastases or another primary tumor were absent. The well-circumscribed neoplasm was located in the thymic region, measured 18 x 12 x 8 cm, and showed a homogeneous, tan-colored, soft cut surface. By histology, the tumor lacked a true capsule and a lobular growth pattern, was almost devoid of stroma, and infiltrated among remnant thymus lobules. The polygonal tumor cells formed solid sheets, trabeculae, or occurred as single cells that resembled hepatocytes. Proliferative activity was low. Portal structures, sinuses, and bile were absent as were areas of conventional thymoma, adenocarcinoma, or germ cell tumor. The tumor expressed cytokeratins 7 and 19, alpha1-antitrypsin, alpha1-antichymotrypsin, and hep-Par-1. Alpha-fetoprotein (AFP), human beta-chorionic gonadotropin (beta-HCG), placental alkaline phosphatase, CD5, CD30, CD31, CD34, CD45, CD68, CD99, S-100, HMB45, desmin, actin, or neuroendocrine markers were not expressed, and intratumorous CD1a+ or TdT+ immature T cells were absent. AFP was repeatedly undetectable in the blood. Mediastinal tumor recurrence was detected 6 months after surgery. Following radiochemotherapy, the patient has remained free of disease for 26 months. We conclude that this tumor is a thymic carcinoma (WHO type C thymoma). A diagnosis of hepatoid yolk sack tumor appears unlikely considering absence of a bona fide germ cell component, lack of AFP expression, and the patient's female gender. Because of its morphologic and immunohistochemical features, we propose the term "hepatoid thymic carcinoma" for this new type of thymic carcinoma.

Hepatoid adenocarcinoma with liver metastasis mimicking hepatocellular carcinoma: an immunohistochemical and molecular study of eight cases

Hepatoid adenocarcinoma (HAC) is a special type of extrahepatic adenocarcinoma, which has a striking morphologic similarity to hepatocellular carcinoma. Seven HACs arising in the stomach and one in the lung, all with liver metastasis, were studied. They shared clinical features, such as old age, high serum alpha-fetoprotein level, aggressive behavior, and hepatic tumor in absence of risk factors for hepatocellular carcinoma (HCC). Morphologically, tumors were characterized by an admixture of tubulo-and/or papillary adenocarcinoma with hepatoid foci. In six cases, liver metastases showed an exclusive hepatoid differentiation, virtually indistinguishable from HCC with solid growth pattern. As HAC and HCC cannot be differentiated on the basis of morphology alone, differences in immunohistochemical reaction patterns would be of considerable diagnostic help. Immunostaining for CK7, CK8, CK18, CK19, CK20, alpha-fetoprotein, p-CEA, and HepPar1 revealed that hepatoid areas of both primary and metastatic HAC have a specific immunoprofile, distinctive of this entity. On the one hand, positivity of virtually all HACs for alpha-fetoprotein, CK8, CK18, and the membranous, canalicular staining for polyclonal carcinoembryonic antigen underline its hepatoid nature. On the other hand, positive staining for CK19 and CK20 and frequent negativity for HepPar1 in both primary tumors and their metastases were distinctive features of HAC. Furthermore, HAC differs from combined hepatocellular cholangiocarcinoma, being negative for CK7. In addition, for comparison of immunohistochemical results, we stained with the same antibody panel a tissue microarray of 121 HCCs. Comparative genomic hybridization study of three HAC supports their hepatoid differentiation as aberrations found in HAC are common in HCC (4q-, 8p-), and hepatoblastoma (Xq+), respectively.