S3338 An Unusual Case of a Large Cell Neuroendocrine Carcinoma and Acute Liver Failure

Abstract

Introduction: Large cell neuroendocrine carcinomas (LCNECs) are characterized as large cells with areas of necrosis, neuroendocrine traits (palisading, trabeculae, etc.), ample cytoplasm and high mitotic rates. LCNECs are a rare, aggressive form of neuroendocrine tumor known to have high rates of metastasis. Our case highlights acute liver failure with rapid progression to death due to metastatic spread of LCNEC. Case Description/Methods: 71-year-old male with a history of prostate cancer requiring prostatectomy, hypertension, hyperlipidemia, and tobacco use, presented for shortness of breath and abdominal pain for 3 days. He was a poor historian and was unable to provide much history. Of note, the patient reported that he had imaging performed in spring 2021 to further evaluate his degenerative disc disease and was told there was concern for a cancerous process. Initial laboratory studies showed an elevated AST and ALT (over 300), and thrombocytopenia, but were otherwise unremarkable. Further imaging was performed, given the patient's history of reported malignancy. Initial chest X-ray was negative for acute findings and an abdominal ultrasound revealed a markedly abnormal appearance of the liver, suggestive of possible hepatic metastatic disease. Computed tomography scan of the chest/abdomen/pelvis showed a left hilar mass measuring 5.5 x 6cm with regional lymphadenopathy. The patient underwent a biopsy of the liver, and was later noted to have worsening liver enzymes, platelets, INR, and renal function, along with a lactic acid. He was transferred to the intensive care unit for further monitoring. Bowel ischemia and portal vein thrombosis were ruled out, and the patient became continually more acidotic, and had a pulseless electrical activity (PEA) arrest. He was revived and intubated, and placed on pressor support and continuous renal replacement therapy. His family decided to change his code status to “do not resuscitate” and the patient was made comfortable. Final results of the liver biopsy were obtained 2 days later, and showed findings consistent with high grade large cell neuroendocrine carcinoma. Immunohistochemical staining was positive for CD56, synaptophysin, CK7 and CK5/6. (Figure) Discussion: Liver metastasis has been documented throughout the literature for other carcinomas, however very few in regards to LCNEC. Acute liver failure in such a short span of time, as in our case, highlights the mortality associated with LCNECs, and the difficulty in diagnosing the condition early in the disease course.Figure 1.: CT abdomen/pelvis showing diffuse heterogeneity of the liver.