2326 Primary Squamous Cell Carcinoma of the Liver: A Rarity

Abstract

INTRODUCTION: Primary liver squamous cell carcinoma (PLSCC) is a very rare entity with less than 40 reported cases since 1970. PLSCC has been known for late diagnosis, high malignancy rate, and poor prognosis of less than 1 year. The exact pathogenesis of PLSCC is unclear, though various theories exist. CASE DESCRIPTION/METHODS: A 72-year-old male with a history of NASH cirrhosis and hepatocellular carcinoma (HCC) status post right hepatic lobectomy 11 years prior and microwave ablation of a presumed recurrent HCC mass just 5 months prior, presented with a 2-month history of progressive fatigue, shortness of breath, lower extremity edema, and abdominal pain. He was hypotensive with an initial blood pressure of 90/54mmHg and had a distended abdomen without evidence of jaundice, encephalopathy, or acholic stools. Labs were notable for WBC 16.9 × 10^3/uL, lactic acid of 4.5mmol/L, and alpha-fetoprotein marker of 1.9ng/mL. CT Abdominal/Pelvis revealed a large burden of diffuse intrahepatic lesions spanning all lobes—findings compatible with HCC—and multiple bilateral kidney simple cysts. Patient underwent an ultrasound guided biopsy of the largest hepatic lesion measuring 2.3 × 2.0 × 2.8 cm. Unfortunately, his condition rapidly worsened with significant elevation in liver enzymes and lactic acid and he passed away. Pathology results resulted shortly after his passing and showed a partially necrotic high grade carcinoma favoring squamous cell carcinoma. It was strongly positive for immunomarkers: CK5, CK7, p40, HSP70 (non-specific), but negative for GATA3, CK20, glypican 3, Hep Par1, S100 protein. DISCUSSION: In this case, the patient was thought to have HCC, but its aggressive clinical course was highly unexpected. Data on the diagnosis of PLSCC is limited and the mechanism is uncertain, though it has a strong association with hepatic cysts, stones, and cirrhosis. Hepatic cysts were not clearly visualized on imaging, though studies do show a positive correlation between the incidence of kidney and hepatic cysts. As this patient had multiple benign bilateral kidney cysts, we suspect that hepatic cysts could have also been present which makes PLSCC very likely given the lack of evidence of a different primary source. A liver carcinoma with such an aggressive clinical course should increase clinical suspicion for PLSCC, however further understanding of the pathogenesis of this disease needs to be investigated.