Primary Hepatic Neuroendocrine Carcinoma with Thrombocytopenia Due to Diffuse Bone Marrow and Splenic Infiltration: An Autopsy Case

An 82-year-old man with fever and back pain was referred to our hospital and was thus found to be thrombocytopenic. A bone marrow biopsy revealed the diffuse infiltration of poorly differentiated neuroendocrine carcinoma (NEC). Computed tomography revealed a large hepatic mass. Considering the risk of bleeding due to thrombocytopenia, a needle biopsy was not performed. The patient rapidly deteriorated and died 10 days after presentation. An autopsy confirmed the diagnosis of primary hepatic NEC, with diffuse metastasis to the spleen, bone marrow, and systemic lymph nodes. This is an extremely rare case of NEC presenting with thrombocytopenia due to extensive bone marrow and splenic infiltration.