Flow cytometry improves the diagnostic value of fine needle aspiration cytology in a spleen with neuroendocrine tumor: A case report

Fine needle aspirations are infrequently performed on the spleen due to concerns for hemorrhagic complications. As a result, splenic lesions can be challenging to diagnose given the limited amount of available specimen. Metastasis to the spleen is rare and metastatic neuroendocrine tumors to the spleen are scarce in literature. The diagnosis of splenic lesions from fine needle aspirate entails processing which prolongs the turnaround time, particularly if the cytomorphology is non‐typical and a limited sample can further complicate this process. We describe a case in which flow cytometry performed on fine needle aspiration of a splenic lesion suggested a diagnosis of neuroendocrine neoplasm involving the spleen. Further workup confirmed this diagnosis. Flow cytometry can recognize neuroendocrine tumors involving the spleen in a timely manner so that appropriate immunohistochemistry tests on limited specimens can be performed to aid in their accurate diagnosis.