Cytologic Aspects of T-Cell Acute Lymphoblastic Leukemia Presenting as a Massive Pericardial Effusion: A Case Report

Acute lymphoblastic leukemia (ALL) with a clinical presentation of cardiac tamponade and the presence of blasts in the pericardial fluid is an uncommon event. A cytopathologist needs to adopt a cautious interpretive approach while dealing with a lymphoid-rich pericardial effusion in order to prevent a false negative diagnosis. A 27-year-old male presented with breathlessness, ascites, bilateral pedal edema and fever. He had mild hepatomegaly. On detailed clinical examination, a diagnosis of anemia with cardiac tamponade was made. Cytology of pericardial fluid revealed a large number of lymphoid cells in a hemorrhagic background that, under low magnification, closely resembled mature lymphocytes. However, a careful examination of May-Grünwald-Giemsa-stained cytologic smears, under an oil immersion objective (x 1,000), showed atypical lymphoid cells having blastoid morphology. Rare lymphoid cells displayed a "hand mirror" appearance. A hematologic workup was carried out to exclude leukemia/lymphoma. Complete blood count revealed pancytopenia with abnormal lymphoid cells. Bone marrow showed replacement by 90% lymphoblasts exhibiting periodic acid-Schiff stain, CD3 and terminal deoxynucleotidyl transferase positivity. A diagnosis of T-cell acute lymphoblastic leukemia (FAB L1) was offered, and the patient was started on a remission and induction regimen. However, he had a rapid downhill course and died of cardiorespiratory arrest. Both clinicians and cytopathologists need to be aware of rare instances in which ALL may present with a pericardial effusion as an initial manifestation. The abnormal lymphoid cells found in the pericardial fluid in such situations need to be interpreted cautiously, as their presence is of clinical significance.