Unique morphologic and clinical features of liver predominant/primary small cell carcinoma - autopsy and biopsy case series

摘要

Liver predominant small cell carcinoma is rare, but often presents as hyper-acute liver failure with unknown primary and is a medical emergency. We present 2 autopsy and 7 biopsy cases of liver predominant small cell carcinoma and demonstrate that these patients present with liver failure and identifiable hepatomegaly, but lack discrete lesions on imaging, as well as no mass lesions identified in other organs including lung. Compared to the multiple nodules of metastatic small cell carcinoma in the liver, unique morphologic feature of liver predominant/primary small cell carcinoma in autopsy and biopsy specimens was a diffuse infiltration of small, blue, neoplastic cells predominantly in the sinusoidal space in the liver parenchyma. Prior to diagnosing liver predominant/primary small cell carcinoma, other infiltrating small blue cell neoplasms including lymphoma and peripheral neuroectodermal tumor need to be ruled out through immunohistochemistry (IHC). We therefore demonstrate that liver biopsy together with a rapid panel of immunostains is necessary to firmly establish a diagnosis of liver predominant small cell carcinoma and allow clinicians to immediately implement potentially lifesaving chemotherapy.