ARTICLE

Year: 2022 | Volume: 11 | Issue: 1 | Page: 16-20 View issue

Hepatic Metastasis from Hepatoid Adenocarcinoma of the Stomach Mimicking Hepatocellular Carcinoma: Diagnostic Challenge

Renu Sukumaran^1*, Anitha Mathews¹, Neelima Radhakrishnan¹

¹Department of Pathology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India.

Abstract

Hepatoid adenocarcinoma (HAC) is a unique type of extrahepatic adenocarcinoma that histologically mimics the appearance of hepatocellular carcinoma (HCC). Hepatoid adenocarcinoma of the stomach has a poor prognosis with increased potential for liver metastasis. HCC and HAC share clinicopathological and immunohistochemical features. The diagnosis of metastatic hepatoid adenocarcinoma to the liver is challenging. It is often misdiagnosed as hepatocellular carcinoma. The diagnostic dilemma is more when the primary tumour is unknown and the first diagnosis is to be established on liver biopsy. Herein, we present the case of a 68-year-old male patient who presented with dysphagia and abdominal discomfort for a three-month duration. Imaging studies showed multiple hypodense lesions in both lobes of the liver. Serum AFP level was markedly elevated to a level of 83,000 ng/ml). A liver biopsy showed atypical polygonal cells in the trabecular pattern. The atypical cells were CK7 negative, CK 20 negative, Hep Par-1 positive and AFP positive. Features were suggestive of hepatocellular carcinoma. Endoscopy showed ulceroproliferative growth in the distal body and antrum of the stomach, a biopsy of which showed atypical cells of similar morphology. The cells were showing focal positivity for CK7, CK20, Hep Par-1 and AFP. On further evaluation, tumour cells in both locations showed positivity for SALL 4. Correlating clinical features, radiology, serum marker values and IHC profile, diagnosis of hepatoid adenocarcinoma of the stomach with liver metastasis was given.

Keywords: Adenocarcinoma, Hepatocellular carcinoma, Hepatoid adenocarcinoma, Metastasis, Stomach

Introduction

Hepatoid adenocarcinoma of the stomach (HAS), is a unique subtype of gastric cancer with specific clinicopathological features. In addition to histological resemblance, HAS and HCC will show positive immunostaining for AFP, Hep Par -1, polyclonal CEA, SALL 4 and Glypican-3. Hepatoid adenocarcinoma of the stomach is characterized by older age, aggressive behaviour and poorer prognosis than usual type adenocarcinoma.^[1] The aggressive biologic behaviour is due to the early involvement of lymph nodes and extensive haematogenous metastasis to the liver.

The pathogenesis of hepatoid adenocarcinoma is still unclear. Recent studies have demonstrated that the increased incidence of hepatoid adenocarcinoma in the stomach may be due to the common embryonic origin of the stomach and liver from the foregut. The tumour may evolve through genetic progression and/or genetic divergence.^[1-6]

Address for correspondence:

Renu Sukumaran,

Department of Pathology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India.

E‑mail: [email protected]

Access this article online

Website: www.ccij‑online.org

DOI: 10.51847/eDDEhTLu0R

Quick Response Code:

The initial presentation of hepatoid adenocarcinoma as liver nodules is challenging, especially in a region with a high prevalence of HCC. Hepatic metastasis from hepatoid adenocarcinoma bears a striking morphologic similarity to HCC. When a patient without any history of hepatitis, liver fibrosis, or cirrhosis present with multiple hepatic nodules with high serum AFP levels, the possibility of metastasis from hepatoid adenocarcinoma should always be considered.^[2]

Case report

A 68-year-old male patient presented with dysphagia and abdominal discomfort for a three-month duration. Imaging studies showed multiple hypodense lesions in both lobes of the liver largest measuring 8.4x7.5x5.1cm in segment VII. Another large lesion was noted in segment IVa measuring 6x5cm. Serum AFP was markedly elevated to a level of 83,000ng/ml. A liver biopsy showed atypical cells in a trabecular pattern with surrounding necrosis. Cells were large

polygonal with moderate to abundant eosinophilic cytoplasm, and enlarged irregular hyperchromatic nuclei (Figures 1a and 1b). The atypical cells were CK7 negative, CK 20 negative, Hep Par-1 positive and AFP positive (Figures 1c and 1d). Features were suggestive of hepatocellular carcinoma. Subsequent upper GI endoscopy revealed irregular ulceroproliferative growth in the stomach involving the body and antrum. Biopsy showed atypical cells arranged in vague glandular patterns and sheets, morphology was similar to the cells in liver biopsy (Figures 2a and 2b). The cells were showing positivity for CK7, CK20, Hep Par-1 and AFP (Figures 3a, 3b, 2c and 2d). Neoplastic cells in both locations showed positivity for SALL4 (Figures 3c and 3d). Correlating clinical features, radiology and serum marker values, a diagnosis of hepatoid adenocarcinoma of the stomach with liver metastasis was given.

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Figure 1. a) Liver biopsy showing large atypical cells surrounded by necrosis (H&E, 100X), b) Higher magnification showing large atypical polygonal cells (H&E, 200X), c) Neoplastic cells showing positivity for Hep par-1 (IHC, 200X), d) AFP positivity (IHC, 200X)