Unique Autopsy and Biopsy Findings of Liver Small Cell Carcinoma – Early Identification of a Treatable Medical Emergency
Amy A Lo, MS Siddiqui, Haonan Li, Wanying Zhang, M Sambasiva Rao, Zong-Ming E Chen, Guang-Yu Yang. Northwestern University, Chicago, IL
Background: Although liver small cell carcinoma is rare, it often presents as hyperacute liver failure with unknown etiology and is a medical emergency. Definitive and rapid pathologic diagnosis is therefore essential for proper treatment.
Design: Autopsy and liver biopsy cases following acute liver failure between 1992 and 2012 were identified to better characterize the morphologic and clinical features of liver small cell carcinoma. Nine cases (3 autopsy and 6 liver biopsy) were identified from patients presenting with acute liver failure secondary to hepatic infiltration by small cell carcinoma. Chart review was performed to identify any previous diagnosis of small cell carcinoma and to analyze all imaging. Diagnosis of liver small cell carcinoma on autopsy or biopsy material was based on morphologic findings and confirmed by immunohistochemical stains in all cases.
Results: All autopsy cases (n=3) and all liver biopsy cases (n=6) presented with hepatomegaly, no previous diagnosis of small cell carcinoma and without a definitive mass lesion identified on imaging. Autopsy cases demonstrated marked hepatomegaly, with livers weighing 2930 - 5360 gm and containing multiple, scattered, small nodules ranging from 3 to 6 mm in size. Histopathologically, small blue neoplastic cells diffusely involved the sinusoidal spaces and almost completely replaced the liver parenchyma in all autopsy and biopsy material. Extensive necrosis was also identified. Immunohistochemistry (IHC) demonstrated that neoplastic cells were positive for CD56, synaptophysin, NSE and cytokeratin AE1/AE3, and negative for CD45 and CD99. Although a sub-carinal lymph node metastasis was identified in one autopsy case, no primary lung tumor or evidence of further metastasis was detected in the other cases on imaging or autopsy despite thorough investigation.
Conclusions: Patients with hyperacute liver failure secondary to small cell carcinoma can present with identifiable hepatomegaly, but lack discrete lesions on imaging. A diffuse small blue neoplastic cell infiltration in the liver parenchyma is a unique morphologic feature that can be identified on biopsy. Other diffuse small blue cell lesions including lymphoma and peripheral neuroectodermal tumor need to be ruled out through IHC prior to diagnosing small cell carcinoma. Therefore, liver biopsy together with a rapid panel of immunostains is necessary to firmly establish a diagnosis of liver small cell carcinoma and allow clinicians to immediately implement chemotherapy.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 11, Wednesday Morning