A 68-Year-Old Man With Neutrophil-Rich Hepatoid Adenocarcinoma of the Gallbladder

Introduction

Hepatoid adenocarcinoma (HAC) is a variety of adenocarcinoma associated with hepatic differentiation [1]. It is aggressive and its prognosis is very poor compared with that of the more common types of adenocarcinoma [2,3]. The tumor is composed mainly of “hepatoid cells”. These cells are characterized by abundant eosinophilic or clear cytoplasm, enlarged nuclei with prominent nucleoli, arranged in a sheet or trabecular pattern [4–11]. Conventional tubular-type gallbladder adenocarcinoma or dysplasia observed in the tumor helps distinguish them from the more common involvement by hepatocellular carcinoma [12]. The stomach is the most common site of HAC. Primary HAC of the gallbladder is relatively rare. To our knowledge, 21 cases of gallbladder HAC have been reported in English in the National Center for Biotechnology Information (NCBI) database, and no study reporting HAC with neutrophilic infiltration, especially with prominent neutrophilic infiltration in the metastases, has been published to date. This report describes the case of a 68-year-old man with neutrophil-rich hepatoid adenocarcinoma of the gallbladder.

Case Report

A 68-year-old man presented to his local hospital with approximately 2 weeks of dull right upper abdominal pain and jaundice. The pain was persistent and worsened after eating. He had worsening fatigue and slight weight loss. He denied fever, anorexia, or night sweats in recent months and had no history of chronic liver disease. At the referring institution, CT demonstrated an infiltrative tumor involving the gallbladder, extrahepatic bile ducts, and adjacent liver tissue. The diagnosis of malignant epithelial neoplasm was confirmed by biopsy. Extrahepatic bile ducts were involved in the tumor mass, resulting in obstructive jaundice. The patient therefore underwent a percutaneous cholecystostomy to ensure adequate biliary drainage in the setting of obstruction at the referring institution. After the procedure, the jaundice abated, but the pain persisted. He was subsequently admitted to our hospital for further management, where an enhanced CT scan was performed to further characterize the lesion. Enhanced CT showed an enlarged gallbladder with a thickened wall and heterogeneous enhancement, a focal area of unclear boundary between the gallbladder and liver parenchyma (Figure 1A). The wall of the common bile duct was thickened (Figure 1B). The liver did not show any space-occupying lesions. Delayed enhancement nodules were seen in the diaphragm and on the right abdominal wall. The chest CT scan was normal. Routine laboratory investigations were performed, showing an increased white blood cell count and CRP, at 12 160/uL (normal range 3500–9500/uL) and 51.46 mg/L (normal range 0–5 mg/L), respectively. The tumor biomarkers (alpha-fetoprotein (AFP), CEA, CA125, CA72–4) of serum were normal. The serum CA19–9 level was elevated, with a concentration of 342.19 KU/L (normal range 0–39 KU/L). Liver enzyme results showed ALT 363.7 U/L (normal range 9–50 U/L), AST 159.1 U/L (normal range 15–40 U/L), ALP 331 U/L (normal range 40–150 U/L), total bilirubin 123.7 umol/L (normal range 0.1–21 umol/L), direct bilirubin 68.16umol/L (normal range 0.1–3.4 umol/L). Serological tests for hepatitis B virus surface antigen and hepatitis C virus antibody were negative.

The cholecystostomy tube caused the patient considerable pain and suffering. The patient and family expressed a strong desire for a local intervention. After thoroughly evaluating the surgical risks and potential benefits for the patient, a consensus was reached with their family to proceed with resection of the gallbladder tumor. The initial surgical plan consisted of partial hepatectomy, hepaticojejunostomy, and cholecystectomy. Exploration during surgery revealed extensive tumor involvement of the hepatic hilum (including the bilateral hepatic ducts, hepatic artery, and portal vein) and the common bile duct, along with infiltration of the adjacent hepatic parenchyma. Therefore, cholecystectomy was subsequently performed, along with partial hepatectomy and resection of multiple intra-abdominal nodules. The surgical specimen included the gallbladder, partially resected liver, a part of the omentum, and nodules from the diaphragm and abdominal wall. Grossly, the gallbladder was enlarged with an irregularly thickened wall (Figure 2).

Histopathological examination revealed a poorly differentiated carcinoma mixed with prominent neutrophilic inflammatory cell infiltration. Some tumor cells were large and polygonal, with eosinophilic granular cytoplasm, round or oval nuclei, prominent or inconspicuous nucleoli, arranged in a sheet or solid pattern with very little fibrous tissue, resembling HCC (Figure 3A). Foci of hepatoid differentiation occupied approximately 40% of the tumor. In some areas, tumor cells exhibited pale cytoplasm with round-to-oval nuclei and vesicular chromatin, lacking gland formation. Signet ring cells characterized by abundant mucin were also noted (Figure 3B). Occasionally, ambiguous glandular structures were identified. The tumor had invaded the adjacent liver and showed both vascular and nerve invasion. Moreover, foci of high-grade dysplasia/carcinoma in situ were observed in the gallbladder epithelium (Figure 3C). The histological findings of the metastatic lesions in the omentum, abdominal wall, and the diaphragm were identical to those of the gallbladder, admixed with remarkable neutrophilic infiltration (Figure 3D).

The immunohistochemistry results of excised tumors displayed CK19 diffuse staining (Figure 4A). SmarcA4 and IN1 were negative. In the hepatoid areas, the tumor cells were positive for hepatocyte paraffin 1 (Hep Par 1) (Figure 4B) and were focally positive for Glypican-3; however, CK7 was negative in these areas (Figure 4C) but positive in others. On histochemical stains, some tumor cells, especially signet ring cells, were positive for mucin (periodic acid-Schiff diastase [PAS-d]) (Figure 4D). Based on the clinical features and imaging data, particularly the histological and immunohistochemical findings, the diagnosis of hepatoid adenocarcinoma of the gallbladder has been confirmed. The patient did not receive any adjuvant therapy following surgery, and he died 1 month after surgery.

Discussion

HAC of the gallbladder is a relatively rare tumor consisting of adenocarcinoma admixed with foci of the tumor, resembling mature and neoplastic hepatocytes. Of the 21 reported cases of hepatoid adenocarcinoma of the gallbladder, 13 were female. The mean age of patients is 67.5 years (ranging from 43 to 82). Peak incidence occurs between the age of 60 to 80 years. Most patients present with abdominal pain, while others present with fatigue or back pain, or are asymptomatic. At the time of diagnosis, 62% of patients already had liver or lymph node involvement [9,13]. HAC was first described in the stomach by Ishikura et al in 1985 [2]. Since then, it has been reported in different organs. The stomach was the most common location (63%), followed by the ovaries (10%), lungs (5%), gallbladder (4%), pancreas (4%), uterus (4%), and urinary bladder (3%) [14]. In patients with HAC, AFP can be positive in the serum and tumor cells, which can support the diagnosis of HAC [5]. AFP positivity can be particularly useful in differentiating HAC of the gallbladder from other primary gallbladder tumors. However, hepatoid adenocarcinoma of the gallbladder does not always produce AFP [15–20]. In our case, AFP is negative in the serum and the tumor cells were also negative for AFP. Therefore, despite the diagnostic value of AFP in HAC, it is crucial to note that a negative test does not rule out the disease. Laboratory tests of tumor markers, such as CA19-9 and CEA, usually were positive [7]. Our patient had an elevated serum CA19-9 level. Histologically, HAC shows sheets or trabeculae of polygonal cells with clear or granular eosinophilic cytoplasm, round nuclei, and prominent nucleoli. The most convincing examples are associated with either conventional tubular-type gallbladder adenocarcinoma or dysplasia, which helps distinguish them from the more common involvement by hepatocellular carcinoma. Immunohistochemically, many liver-specific proteins, including AFP, HepPar-1, albumin, protein induced in the absence of vitamin K, transferrin, a1-antitrypsin, and canalicular CD10, have been reported in tumor cells [17]. Adenocarcinoma of the bile duct is immunoreactive for CK7, 8, 18 and 19 [9,17,21]. In our case, hepatoid differentiation was manifest by large and polygonal cells with eosinophilic granular cytoplasm, round or oval nuclei and prominent or inconspicuous nucleoli, arranged in a sheet or solid pattern, with very little fibrous tissue. Furthermore, these tumor cells were positive for HepPar-1, GPC and CK19, but negative for CK7. The immunohistochemical findings in our patient are consistent with those reported in most of the literature [9]. High-grade dysplasia of the adjacent lining epithelium and a few signet ring cells positive for mucin (PAS-d) were observed in the tumor, which suggests that the tumor originated from the gallbladder mucosa.

In addition, in our case, there was prominent neutrophilic inflammatory cell infiltration in the tumor. The presence of neutrophil infiltration within the tumor, particularly within metastatic sites, has not been previously described. High levels of tumor-associated neutrophils are correlated with shorter survival in patients with cervical carcinoma and lung squamous cell carcinoma [22,23]. Bosch et al also found that neutrophilic inflammation is an important feature of pancreaticobiliary neoplasia [24]. Notably, in our case, remarkable neutrophilic inflammatory cell infiltration in the absence of necrosis was also observed in the metastases, which suggests that the presence of neutrophilic inflammatory cells may be associated with the tumor cells. The tumor cells could likely recruit neutrophilic inflammatory cells into the tumor. Therefore, more studies, such as immunochemistry and genetic tests, are necessary to demonstrate the potential biological, clinical, and prognostic relevance of HAC infiltrated by neutrophils.

The differential diagnosis includes neutrophil-rich hepatocellular carcinoma (NR-HCC) and combined hepatocellular-cholangiocarcinoma (cHCC-CC) invading the gall bladder. NR-HCC is a new subtype of HCC defined in the fifth edition of the WHO classification of digestive system tumors as a tumor infiltrated by neutrophils that outnumber tumor cells in most fields. The new subtype is associated with a worse prognosis [25]. It shows poor cellular differentiation. Histologically, very similar to our case, the tumor has moderate-to-marked cellular pleomorphism and there is prominent neutrophilic inflammatory cell infiltration in the tumor [26]. However, in our case, the presence of signet ring cells and the foci of high-grade dysplasia/carcinoma in situ did not suggest NR-HCC. Immunohistochemistry is not very helpful in the differential diagnosis of these 2 tumors because tumor cells in NR-HCC are also positive for HepPar-1, GPC, and CK19 [26]. HepPar-1 negative expression is more suggestive of poorly differentiated NR-HCC, which often shows negative HepPar-1. Another differential diagnosis is combined hepatocellular-cholangiocarcinoma (cHCC-CC) invading the gallbladder. The 5th WHO definition of cHCC-CC is a primary liver carcinoma characterized by the unequivocal presence of both hepatocytic and cholangiocytic differentiation within the same tumor [12]. Liver disease and cirrhosis are clinical features of cHCC-CCA. Histologically, in cHCC-CCA, the hepatocytic and cholangiocytic tumor areas may show all the architectural and cytological differentiation patterns described for HCC and iCCA, respectively. The immunohistochemical markers of cHCC-CC and HAC are the same. Neoplastic cells in both tumors can be positive for HePar-1, AFP, GPC-3, CK7, and CK19 [17,27–29]. Our patient did not have chronic liver disease or cirrhosis. Histologically, foci of high-grade dysplasia/carcinoma in situ were noted in the gallbladder epithelium adjacent to the tumor, suggesting the tumor originated in the gallbladder. Furthermore, the radiological features and tumor location also indicated that the tumor originated in the gallbladder, not in the liver.

Conclusions

We have presented a case of HAC of the gallbladder with prominent neutrophilic infiltration. The presence of neutrophilic infiltration in the absence of necrosis within the metastases is a particularly notable feature, indicating that the presence of neutrophilic inflammatory cells can be associated with the tumor cells and may hold potential biological, clinical, and prognostic significance.