Hepar-1 Positive Prostatic Adenocarcinoma: A Case Report and Review of Literature

Abstract

Abstract Introduction/Objective Poorly differentiated metastatic malignancy in patients with a history of more than one known primary tumor, such as a history of both hepatocellular and prostatic carcinoma as seen in our case, can be challenging. Both tumors are CK7/CK20 positive, and both can be reactive for hepar-1, as has been demonstrated in the current case, and rarely described in the literature. Methods/Case Report Herein we present a sixty-three-year-old male who presented for follow-up of his lower back pain in the setting of hepatocellular carcinoma. MRI of the spine was suggestive of an expansile metastatic lesion in the C2 vertebral body with extraosseous soft tissue extension resulting in moderate to severe central canal and left foraminal narrowing at C2-3. Multiple additional metastatic lesions were visualized throughout the cervical upper thoracic spine as detailed above. Vertebral body biopsy showed metastatic adenocarcinoma with sheets of neoplastic cells infiltrating the medullary spaces. The patient’s history of hepatocellular carcinoma was noted, and immunohistochemical staining for HepPar1 with appropriate control was performed and found to be diffusely reactive in the tumor cells. However, tumor cells were also positive for PSA, PSAP, and NKX3.1 (Fig-1-A-D, H&E, Hepar-1, PSAP, PAP). This immunoprofile is consistent with a prostatic origin of the tumor cells, and a diagnosis of metastatic prostatic adenocarcinoma was given. Results (if a Case Study enter NA) NA. Conclusion Hepar-1 and even arginase-1 have been observed in rare subsets of prostatic acinar adenocarcinoma. Even in the setting of PSA and PSAP negative metastatic disease in patients with a history of hepatocellular carcinoma, we suggest utilizing additional stains suggestive of a prostatic origin, such as NKX3.1, and even molecular studies. This could be useful diagnostic approach to help differentiate between the two neoplasms in such patients.