Occult Component of Hepatocellular Carcinoma Presenting as Metastatic Neuroendocrine Carcinoma of Unknown Primary: An Autopsy Case
VB Korcheva, AJ Jensen, SL Orloff, P Stenzel. Oregon Health and Science University, Portland, OR
Background: Hepatocellular carcinoma (HCC) is one of the common causes of cancer-related deaths worldwide. HCC commonly exhibits histologic polymorphism with rare cases described to have tumor cells with neuroendocrine features. The origin of these cells is unknown. It has been speculated that they either represent a histological component of the original HCC or differentiation under certain circumstances. The prognosis and treatment of HCC with neuroendocrine differentiation is uncertain; however, the few existing reports show this tumor to have higher proliferative activity and malignant potential than ordinary HCC. We report an unusual case of HCC with neuroendocrine component with metastases, some of which composed entirely of the neuroendocrine component.
Design: Formalin fixed, paraffin embedded tissue was stained with H&E. Immunohistochemical stains with HepPar1, alpha-fetoprotein (AFP), thyroid transcription factor (TTF-1), synaptophysin (SYN), and chromogranin (CHR) were performed by using Ventana System and kits.
Results: The patient was a 54-year-old female with history of hepatitis C who underwent a liver transplant in 2008. Evaluation of the explanted liver showed a 1.0 cm moderately differentiated HCC with angiolymphatic invasion. The clinical course of the patient was complicated with retroperitoneal lymphadenopathy, biopsy of which showed high grade neuroendocrine carcinoma. The patient underwent chemotherapy, complicated with angioinvasive fungal infection. At the time of autopsy retroperitoneal lymphadenopathy and a lung nodule were noted. No possible primary site of malignancy was found. Lymph nodes retained metastatic neuroendocrine carcinoma. Examination of the lung nodule showed metastatic HCC with features identical to the primary liver tumor. Review of the surgically resected liver tumor revealed a population of small cells with neuroendocrine features, dispersed among ordinary HCC. These cells were negative for HepPar1, AFP&TTF-1 and positive for SYN&CHR.
Conclusions: We report an unusual case of HCC admixed with neuroendocrine carcinoma with multiple metastases, characterized by two distinct phenotypes- one, similar to the primary HCC lesion and second, composed entirely by the high grade neuroendocrine component. An occult neuroendocrine component of hepatocellular carcinoma may present as metastatic neuroendocrine carcinoma with an occult primary site.
Wednesday, March 24, 2010 9:30 AM
Poster Session V # 2, Wednesday Morning