Pancreatic hepatoid carcinoma: a review of the literature

FDG PET/CT in Staging of α-Fetoprotein-Producing Hepatoid Adenocarcinoma of the Pancreas

ABSTRACT

Hepatoid adenocarcinoma of the pancreas is a rare aggressive tumor with poor prognosis. We describe contrast-enhanced CT and FDG PET/CT findings in a case of pancreatic hepatoid adenocarcinoma with significantly elevated α-fetoprotein level presenting as acute pancreatitis. The primary pancreatic tumor diffusely involved the pancreas and showed heterogeneous enhancement mimicking acute necrotizing pancreatitis on contrast-enhanced CT. FDG PET/CT showed intense FDG uptake (SUVmax, 24.5) of the left supraclavicular and retroperitoneal lymph node metastases, suggesting FDG PET/CT may be useful for staging of this aggressive tumor.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Case report and literature analysis: pancreatic hepatoid carcinoma with multiple lymph node metastases progressing to liver metastasis after pancreaticoduodenectomy

Hepatoid carcinoma is an extrahepatic primary tumor displaying characteristics reminiscent of hepatocellular carcinoma differentiation, which is found in various organs, such as the stomach, ovaries, gallbladder, and pancreas. Reports of pancreatic hepatoid carcinoma remain scarce. Consequently, understanding of this disease remains a priority, with no established consensus on its diagnosis and management. Here, we reported the case of a 45-year-old woman diagnosed with hepatoid carcinoma located in the pancreatic head, accompanied by multiple lymph node metastases. Following pancreaticoduodenectomy, the patient developed liver metastases within 3 months. Subsequently, she underwent adjuvant therapy consisting of Teysuno and Durvalumab following microwave ablation for the liver metastases. Remarkably, the patient has survived for one year without significant disease progression. This case underscores the potential efficacy of immunotherapy as a promising treatment option for pancreatic hepatoid carcinoma. Further research and clinical trials are warranted to explore the optimal management strategies for this rare and challenging malignancy.

Focal Hepatocellular Carcinoma in Pancreas

A 67-year-old man was found to have a pancreatic head mass on abdominal ultrasound. He had compensated liver cirrhosis due to hepatitis C. The fine-needle aspiration (FNA) biopsy of the mass reported an adenocarcinoma of the pancreas, while the subsequent histopathology report of the supraclavicular lymph node showed features of hepatocellular carcinoma (HCC). A second read and additional stains on the FNA specimen confirmed a hepatoid (hepatocellular) carcinoma of the pancreas. He received atezolizumab and bevacizumab and had a good response. Tumors with features of HCC outside of the liver rarely occur and even more rarely in pancreas, with less than 50 cases reported so far. Pure HCC-like morphology is the most common histological form among four subtypes and has a relatively better prognosis. Surgical resection is considered the treatment of choice if amenable and variable outcomes are reported with different chemotherapies. Challenges exist in the diagnosis and the management of this rare and intriguing entity, and the potential misdiagnosis can have grave consequences as the management is completely different for a pancreatic adenocarcinoma and hepatoid carcinoma. We report a case with a challenging diagnosis of metastatic pancreatic hepatoid carcinoma which was treated as unresectable HCC with immunotherapy and the patient had a good response.

Hepatoid adenocarcinoma-Clinicopathological features and molecular characteristics

Hepatoid adenocarcinoma (HAC) is a rare, malignant, extrahepatic tumor with histologic features similar to those of hepatocellular carcinoma. HAC is most often associated with elevated alpha-fetoprotein (AFP). HAC can occur in multiple organs, including the stomach, esophagus, colon, pancreas, lungs, and ovaries. HAC differs greatly from typical adenocarcinoma in terms of its biological aggression, poor prognosis, and clinicopathological characteristics. However, the mechanisms underlying its development and invasive metastasis remain unclear. The purpose of this review was to summarize the clinicopathological features, molecular traits, and molecular mechanisms driving the malignant phenotype of HAC, in order to support the clinical diagnosis and treatment of HAC.

Hepatoid tumors of the gastrointestinal/pancreatobiliary district: morphology, immunohistochemistry, and molecular profiles

Hepatoid tumors (HTs) histologically resemble hepatocellular carcinoma (HCC) but manifest outside the liver. Regarding immunohistochemistry (IHC), the classical markers of hepatoid differentiation are Hep Par-1, CD10, and arginase-1. This study provides a critical overview of HT in the gastrointestinal/biliopancreatic system, which is the most common site of origin. Gastric HTs are malignant neoplasms recognized by the current WHO classification as a variant of adenocarcinoma. In addition to the classic IHC markers, SALL4 and claudin-6 can help exclude a metastatic HCC at this site. Next-generation sequencing revealed the most common alterations, including TP53 mutation, microsatellite instability (MSI), and Her2 amplification. Esophageal HTs are exceptionally rare and usually arise in the context of Barrett's esophagus. In the intestine, HTs are classified within the adenocarcinoma spectrum and manifest more often in the background of inflammatory bowel disease. Regarding their molecular profile, recurrent alterations included MSI and NCOA4-RET fusions. In the pancreas, the current WHO classification acknowledges HT only as a possible variant of ductal adenocarcinoma, characterized by a poor prognosis. However, at this site, neuroendocrine tumors (NETs) and solid pseudopapillary neoplasms (SPNs) may also show hepatoid differentiation. Hepatoid NETs show aggressive behavior, whereas hepatoid SPNs harbor CTNNB1 mutations and are characterized by an indolent clinical course. Lastly, biliary HTs belong to the adenocarcinoma category and usually show a poor prognosis. In conclusion, gastrointestinal/pancreatobiliary HTs show specific histomolecular features, which should be considered for improving routine diagnostic activity and clinical management.

"Pure" hepatoid tumors of the pancreas harboring CTNNB1 somatic mutations: a new entity among solid pseudopapillary neoplasms

Hepatoid tumors (HTs) represent a rare group of neoplasms that are histologically similar to hepatocellular carcinoma but arise outside the liver. The current World Health Organization classification recognizes the hepatoid morphology of pancreatic tumors only as a possible variant of pancreatic ductal adenocarcinoma (PDAC). Here, we describe two cases of "pure" HT of the pancreas showing common features and characterized by indolent biological behavior. These tumors were roundish nodules with pushing borders, hyaline globules, and pure hepatoid histology; they were diffusely positive for β-catenin and LEF1 on immunohistochemistry. At next-generation sequencing, both neoplasms harbored only one pathogenic somatic mutation that affected the CTNNB1 gene at exon 3 and showed a loss of heterozygosity on chromosomes 18 and 21. By integrating macroscopic and microscopic features, along with their molecular profiles, we advocate that such tumors represent a distinct entity from PDAC and should be considered a new variant of solid pseudopapillary neoplasms. The recognition of this new neoplastic category may have immediate implications not only for tumor taxonomy but also for clinical practice.

Genomic characterization of hepatoid tumors: context matters

Hepatoid tumors (HT) are rare neoplasms morphologically resembling hepatocellular carcinoma, which arise in several organs other than the liver. A comprehensive molecular profile of this group of neoplasms is still lacking. Genomic characterization of 19 HTs from different organs (three colon HTs, four esophagogastric HTs, four biliary HTs, six genitourinary HTs, two lung HTs) was performed using a multigene next-generation sequencing panel. NGS unraveled a composite molecular profile of HT. Their genetic alterations were clearly clustered by tumor site: (i) colorectal HT displayed microsatellite instability, high tumor mutational burden, mutations in ARID1A/B genes and NCOA4-RET gene fusion (2/3 cases); (ii) gastric HT had TP53 mutations (2/4); (iii) biliary HT displayed loss of CDKN2A (3/4) and loss of chromosome 18 (2/4); (iv) genital HT showed gain of chromosome 12 (3/6); (v) lung HT had STK11 somatic mutations (2/2). The only commonly mutated gene occurring in HT of different sites was TP53 (8/19 cases: colon 2, esophagogastric 2, biliary 2, genital 1, lungs 1). This study shows that most genetic alterations of HT were clustered by site, indicating that context matters. The novel potential targets for HT precision oncology are also clustered based on the anatomic origin. This study shed light on the biology of these rare cancers and may have important consequences for treatment decisions and clinical trial selection for HT patients.

Hepatoid carcinoma of the pancreas: A case report and review of the literature

BACKGROUND

Hepatoid carcinoma (HC) is an extremely rare neoplasm that is morphologically similar to hepatocellular carcinoma. HC has been described in various organs; however, HC of the pancreas is extremely rare. To our knowledge, only 38 cases have been reported. We present a case of HC of the pancreas in a 36-year-old male patient.

CASE SUMMARY

A 36-year-old cachexic man with no significant past medical history was transferred to our hospital with a history of painless jaundice, elevated blood glucose and significant weight loss. Lab tests showed elevated serum transaminases, bilirubin and alpha-fetoprotein levels. Magnetic resonance imaging of the upper abdomen showed a diffusely enlarged pancreas, appearing “sausage-shaped”. Magnetic resonance cholangiopancreatography showed upstream ductal dilation secondary to stricture of the main pancreatic duct and the common bile duct, which were not visible. Immunohistochemistry of biopsied tissue from a percutaneous pancreatic biopsy showed tumor cell positivity for HepPar1, polyclonal carcinoembryonic antigen and CK19, suggestive of HC of the pancreas. The characteristics of 39 patients with HC of the pancreas were reviewed.

CONCLUSION

HC of the pancreas is more prevalent in males, and patients have a median age of 57 years. It is most commonly asymptomatic or presents as abdominal back pain, and the pancreatic tail is the most common location. At the time of diagnosis, liver metastasis is often present.

Therapeutic Approaches to Gastric Hepatoid Adenocarcinoma: Current Perspectives

Hepatoid adenocarcinoma of the stomach (HAS) is a rare subgroup of gastric cancer (GC). Morphologically, this tumor exhibits both adenocarcinomatous and hepatocellular differentiation, and most tumors show immunohistochemical staining for alpha-fetoprotein (AFP) or elevated AFP serum levels. The diagnosis of HAS is frequently delayed, and at least half of patients have advanced disease at the time of diagnosis. Despite a lack of evidence, treatment approaches have mostly followed principles for the treatment of common gastric cancer (CGC), including radical surgery in eligible patients with curative intent. The indications for and the type of adjuvant systemic treatments remain unclear. Additionally, there is a lack of evidence allowing any firm conclusions to be drawn regarding the best treatment for patients with metastatic HAS (mHAS). Chemotherapy regimens, including cisplatin-based chemotherapy, are considered the most efficient first-line systemic treatment in advanced situations. Their combination with targeted therapy (i.e., trastuzumab) in HER2-positive tumors seems promising. The rarity of these patients and the scarce and heterogeneous literature on this particular subgroup of GC make it difficult to provide any robust evidence for the clinical management of patients with HAS.

Pure pancreatic hepatoid carcinoma: a surgical case report and literature review

Background

Hepatoid carcinoma (HC) is an extra-hepatic neoplasm that shares the morphological and immunohistochemical features of hepatocellular carcinoma. Pancreatic HC exists as either pure or combined type. Pure pancreatic HC is extremely rare, with only a few cases reported in the literature to date. Because of the rarity of pure pancreatic HC, its clinical features including incidence, behavior, and prognosis remain unclear. We herein report the case of a 56-year-old man who developed pure pancreatic HC treated with surgical resection. We also include a review of the existing literature.

Case presentation

A 56-year-old male patient was admitted to our hospital after a pancreatic cyst was identified by abdominal ultrasonography on a comprehensive medical examination. Endoscopic ultrasound revealed a cystic mass measuring 13 mm in size in the pancreatic head and a low-density mass measuring 16 mm in size in the pancreatic tail, which was partially enhanced on contrast-enhanced ultrasound. Contrast-enhanced computed tomography (CT) revealed a branch duct type intraductal papillary mucinous neoplasm in the pancreatic head and an early enhanced nodule measuring approximately 10 mm in size in the pancreatic tail. Endoscopic ultrasound-guided fine-needle aspiration of the hypervascular tumor was performed. The hypervascular tumor was suspected to be a solid pseudopapillary neoplasm. Laparoscopic spleen-preserving distal pancreatectomy was performed. Histology was identical to hepatocellular carcinoma of the liver. Immunohistochemically, the tumor cells were positive for hepatocyte paraffin 1, and a canalicular pattern was confirmed on the polyclonal carcinoembryonic antigen staining. The patient was diagnosed with a moderately differentiated pancreatic HC. The patient was followed up without adjuvant chemotherapy, and there was no evidence of recurrence at 6 months post-operatively.

Conclusions

We present a case of moderately differentiated pure pancreatic HC. For the accurate preoperative diagnosis of pure pancreatic HC, biopsy is preferred to cytology or preoperative imaging studies such as CT. The prognosis of pure pancreatic HC depends on its differentiation.

Pathology of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy and estimated to become the second leading cause of cancer-related deaths by 2030. Although overall 5-year survival rates have constantly remained below 10% for the last decades, several key points important for accurate patient stratification have emerged during recent years. These key points include a highly standardized gross examination of PDAC resection specimens, using an axial slicing technique and inking of the circumferential resection margin (CRM), as well as a meticulous microscopic examination, taking into account the prognostic relevance of factors such as the exact resection status (R0 vs. R1 1-mm vs. R1 resection), histopathological tumor grading and the so-called lymph node ratio (LNR). With increasing use of neoadjuvant therapy in PDAC, tumor regression grading (TRG) for PDAC is currently rising in relevance in order to stratify and manage pre-operatively treated PDAC patients. As all current TRG systems for PDAC are unsatisfactory, new standardized international protocols are urgently needed. Several morphological subtypes of PDAC exist, some of which share the same molecular background with classical PDAC, while others are characterized by a distinct molecular pathogenesis. While some show a prognosis similar to classical PDAC, other subtypes stand out due to a better or even worse prognosis than classical PDAC. Prognostic relevant molecular subtypes of PDAC have been proposed as well, however, limitations of used cohorts and the lacking correlation of molecular subtypes with histomorphological subtypes limit the translation of these findings into valuable clinical applications. Lastly, several macroscopic and microscopic precursor lesions of PDAC have been described in genetically engineered mouse models (GEMM) and humans in recent times, providing further insight into PDAC carcinogenesis. In addition, improved diagnosis of PDAC precursors represents a chance to select patients for resection before invasive PDAC is present.

Rare Tumors and Lesions of the Pancreas

There are a few entities that account for most solid and cystic masses of the pancreas. The pancreas harbors a wide array of diseases, including adenocarcinoma, and its variants, such as anaplastic and adenosquamous carcinoma. Other neoplasms include acinar cell carcinoma, solid pseudopapillary tumor, and sarcomas. Benign lesions include hamartomas, hemangiomas, lymphangioma, and plasmacytoma. Isolated metastases include renal cell carcinoma, melanoma, and other carcinomas. Benign inflammatory conditions, such as autoimmune pancreatitis and groove pancreatitis can also mimic solid neoplasms of the pancreas.

Neoadjuvant modified-FOLFIRINOX followed by surgical resection of both the primary and metastatic tumors of a pancreatic hepatoid carcinoma with synchronous liver metastasis: A case report

RATIONALE

Pancreatic hepatoid carcinoma (PHC) is a rare form of pancreatic malignancy mimicking hepatocellular carcinoma (HCC) in morphology, immunohistochemistry, and behavior. PHC usually has an aggressive clinical course and poor prognosis. Effective treatment strategies are lacking due to poor understanding and extreme rarity of such kind of malignancy. PATIENT CONCERNS:: we present the case of a 75-year-old man with tumors in the liver and the tail of pancreas that were detected in a routine health check-up.

DIAGNOSES

Pancreatic hepatoid carcinoma with liver metastasis INTERVENTIONS:: The patient was treated by neoadjuvant modified-FOLFIRINOX (mFOLFIRINOX) chemotherapy and subsequent resection of both the primary pancreatic tumor and the sole liver metastasis.

OUTCOMES

Pathology findings confirmed complete pathological response of the liver metastatic tumor and partial response of the primary pancreatic tumor to neoadjuvant mFOLFIRINOX. Adjuvant chemotherapy with mFOLFIRINOX was given and until now the patient has a progression-free survival of 13 months after diagnosis.

LESSONS

PHC are often associated with early liver metastasis and a poor prognosis, surgical resection combined with neoadjuvant and adjuvant FOLFIRINOX chemotherapy is proved to be efficient in such kind of malignancy, even with liver metastasis.

Immunohistochemical approach for the diagnosis of a liver mass on small biopsy specimens

Well-differentiated hepatocellular carcinoma (HCC) shares overlapping histological features with benign hepatocellular lesions, including hepatocellular adenoma and focal nodular hyperplasia in non-cirrhotic liver, and with high-grade dysplastic nodule in cirrhotic liver. Several metastatic tumors, such as neuroendocrine tumor, renal cell carcinoma, adrenocortical carcinoma, melanoma, and epithelioid angiomyolipoma, can be indistinguishable from HCC on histologic grounds. Since this distinction has important therapeutic implications, judicious use of immunohistochemical markers plays an important role in establishing an accurate diagnosis, especially when limited material of tumor is available on cell block or a small core biopsy. This review describes commonly used immunohistochemical markers used in the diagnosis of HCC, highlighting advantages and disadvantages of each marker, and suggests appropriate immunohistochemical panels for specific clinicopathologic situations.

Hepatoid Carcinoma of the Pancreas: Case Report, Next-Generation Tumor Profiling, and Literature Review

Fewer than 25 cases of hepatoid carcinoma of the pancreas have been reported in the literature. We present a case in a 61-year-old male with a remote history of Hodgkin's lymphoma and gastric neuroendocrine cell hyperplasia. On surveillance endoscopic ultrasound, an 8 × 5 mm cystic lesion was seen in the tail of the pancreas. MRI showed a focal pancreatic duct cut-off with mild ductal dilation. Fine needle aspiration was performed, which was concerning for acinar cell carcinoma. The patient underwent distal pancreatectomy and recovered uneventfully. Final pathology demonstrated a 1.3-cm hepatoid carcinoma of the pancreas, with a final clinicopathological stage of T1N0M0. Next-generation nucleic acid sequencing of the tumor did not suggest a viable adjuvant chemotherapeutic agent, and no adjuvant therapy was administered. The patient has no evidence of disease 6 months following resection. A further characterization and description of the outcomes of these rare tumors is warranted to help guide providers and counsel patients.

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.

Ectopic Hepatocellular Carcinoma Occurring in the Bile Duct and Extending to the Gallbladder

Ectopic hepatocellular carcinoma (HCC) is rare and there has been no report on ectopic HCC arising from both the bile duct and the gallbladder. It is difficult to establish a correct diagnosis for this kind of HCC based on preoperative imaging. All of the preoperative imaging examinations misdiagnosed the HCC as cholangiocarcinoma in our case. However, via retrospective analysis of this case, we found that the patient was positive for hepatitis virus markers and that a tumor marker (α-fetoprotein) was significantly elevated. Therefore, diagnosis of HCC with significantly elevated α-fetoprotein (>200 μg/L) is highly likely, particularly with chronic hepatitis and excluding pregnancy and tumor of genital system.

A hepatoid carcinoma of the pancreatic head

Hepatoid carcinoma (HC) is an extremely rare form of neoplasm. Its cellular structure resembles that of a hepatocellular carcinoma (HCC). To date, only 26 cases of hepatoid carcinoma of the pancreas have been reported in the literature. We report the diagnosis of a hepatoid carcinoma of the pancreatic head in a 78-year-old male patient. The tumor was detected incidentally during routine abdominal ultrasound scanning. Laboratory tests did not show any abnormalities except for a monoclonal gammopathy of undetermined significance. After CT, MRI, and laparoscopic biopsy that failed to obtain the diagnosis, the patient underwent a Whipple procedure. The final pathology report described a hepatoid carcinoma of the pancreatic head (pathological T3, N0 (0/10), L0, V0, R0, M0). After the patient recovered, no further therapy was recommended by the tumor board and he was discharged. Regular follow-up was suggested; however, the patient suddenly died of acute coronary artery disease 2 months after surgery.

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 Carcinoma of the Pancreas: A Case Report and Review of the Literature

Background: Hepatoid carcinoma (HC) is a rare extrahepatic malignancy that shares many morphological and serological features with hepatocellular carcinoma. HC has been reported to arise from several organs that are derived from the foregut endoderm, including the stomach, gallbladder, and pancreas. We present a case of an elderly man with hepatoid adenocarcinoma of the pancreatic head with duodenal invasion, presenting with pancreatitis and a gastrointestinal bleed. With only 23 reported cases at the time of our literature search, we discuss the presentation, histopathology, and management of such a rare disease.

Case presentation: A 71-year-old man presented initially with abdominal pain and was treated conservatively for pancreatitis. Four months later, he presented with melena and anemia. His examination was noncontributory. Esophagogastroduodenoscopy revealed a friable ampulla of Vater, and a CT scan of the abdomen showed a 4.5 cm pancreatic head mass. Fine needle aspirate revealed an epithelioid neoplasm with hepatoid morphology. Serum α-fetoprotein was normal. Surgical resection confirmed hepatoid adenocarcinoma of the pancreas with positive lymphadenopathy and negative margins. There was no radiographical or gross evidence of distant spread. Observation and adjuvant gemcitabine were discussed as possible options. The patient elected to receive care closer to home and will continue surveillance imaging.

Conclusion: With only 23 reported cases, pancreatic HC represents a rare entity within gastrointestinal oncology. There is no clear postoperative adjuvant standard therapy for this likely heterogeneous group of tumors. Although surgical resection is the mainstay of upfront treatment, metastatic disease to the lymph nodes or liver portends a poor prognosis and may warrant treatment such as transarterial embolization, chemotherapy, or radiotherapy.

Application of immunohistochemistry in gastrointestinal and liver neoplasms: new markers and evolving practice

CONTEXT

Diagnosis of primary gastrointestinal and liver neoplasms is usually straightforward. Immunohistochemistry is most helpful to differentiate metastatic carcinomas with morphologic similarity and to resolve tumors of unknown origin. Recently, several new markers highly sensitive and specific for primary liver and gastrointestinal tumors have been discovered. Their potential diagnostic application has not been widely appreciated by general practicing pathologists. In addition, a new trend in immunohistochemistry application has started, focusing on assessing predictive markers (such as human epidermal growth factor receptor 2) and mutation-specific markers (v-raf murine sarcoma viral oncogene homolog B V600E) to directly guide clinical management. Practicing pathologists need to be aware of and prepared for this evolving trend.

OBJECTIVES

To summarize the usefulness of several recently discovered immunohistochemical markers in the study of gastrointestinal and liver tumors; to suggest the most current and effective immunohistochemical panels addressing common diagnostic challenges for these tumors; to share practical experience and useful tips for human epidermal growth factor receptor 2 testing in gastric and gastroesophageal junction adenocarcinoma and v-raf murine sarcoma viral oncogene homolog B V600E immunohistochemistry in colorectal carcinoma.

DATA SOURCES

Sources include literature review, and authors' research data and practice experience. The cases illustrated are selected from the pathology archives of the Geisinger Medical Center (Danville, Pennsylvania).

CONCLUSIONS

Application of immunohistochemistry in gastrointestinal and liver tumors continues to evolve. New tumor-specific markers constantly emerge and help pathologists to further improve diagnostic accuracy. Assessment of predictive and prognostic markers by immunohistochemistry in routine pathologic diagnosis is a new trend and will greatly facilitate the advancement of personalized cancer therapy.

Pancreatic hepatoid carcinoma: a rare form of pancreatic neoplasm

Primary pancreatic hepatoid carcinoma (PHC) is extremely rare, resembling hepatocellular carcinoma (HCC) in terms of morphology and immunohistochemical features. Hepatoid carcinoma can present in other organs, most noticeably in the stomach. PHC is present in two forms either a pure form like HCC or admixed with other histologic tumor components characteristic of the underlying primary site (endocrine tumors, ductal, or acinar adenocarcinomas). Here, we report a 69-year-old male patient with distal pancreatic mass incidentally found during a CT scan workup for a pulmonary nodule suspicious for metastatic prostate adenocarcinoma. We described the clinical, cytological, and histological finding and conducted a literature review.

Hepatoid carcinoma of the pancreas

Background

Hepatoid carcinoma of the pancreas is extremely rare. This article tries to summarize the clinical features and outcomes of pancreatic hepatoid carcinoma.

Methods

The data pool for analysis includes the case we encountered with hepatoid carcinoma of the pancreas and the reported cases in the literature.

Results

Twenty-three cases of hepatoid carcinoma of the pancreas were analyzed. This tumor occurred more frequently in male than in female patients (69.6 vs. 30.4 %). Tumor sizes range from 0.5 to 11.0 cm with median of 6.0 cm. The most common symptom was epigastric pain (36.4 %). When the tumor locates at pancreatic head, nausea/vomiting (62.5 %) is more common, followed by jaundice and epigastric pain (50.0 %). For those at pancreatic body-tail, 42.9 % of the patients presented no symptom. Alpha-fetoprotein (AFP) was abnormally elevated in 60 % of the cases. Hepatoid carcinoma in the pancreas could be either pure form or mixed form with other malignancy (40.9 %), with the most common coexisted pathology of malignant neuroendocrine tumor (22.7 %). Metastasis occurred in 36.4 % of the cases at the diagnosis of this tumor, including liver metastasis in 31.8 % and lymph node metastasis in 21.1 %. The overall 1-year survival rate was 71.1 % and 5-year 40.4 %, with a median of 13.0 months. Unresectability, hepatic, and lymph node metastases are associated with negative impact on survival outcome.

Conclusions

Elevation of serum AFP may be a clue leading to the diagnosis of pancreatic hepatoid carcinoma. This tumor could be mixed form with other malignancy. Surgical resection should be the treatment of choice whenever possible.