Immature Terminal Deoxynucleotidyl Transferase Positive B Cells are Detected in a Subset of Adult and Pediatric Liver Biopsies

摘要

Reactive lymphoid infiltrates are common in the liver and may be related to underlying medical liver disease (eg, viral hepatitis) or may present adjacent to a tumor, as a peritumoral effect. When prominent (or in some clinical settings), hepatic lymphoid infiltrates may raise concern for lymphoma/leukemia. In our consultation practice, we have encountered several instances in which a diagnosis of B-lymphoblastic leukemia/lymphoma (B-ALL) was first suggested on liver biopsy, but definitive diagnosis can be challenging on hematoxylin and eosin (H&E)-stained sections, as there are many liver diseases that can present with prominent portal and sinusoidal hematolymphoid infiltrates, which may include immature-appearing cells [eg, erythroid precursors or immature myeloid cells in extramedullary hematopoiesis (EMH)]. Terminal deoxynucleotidyl transferase (TdT) is a nuclear enzyme restricted to precursor lymphoid cells1'2 and their malignant counterparts.3"5 Immunohistochemistry for TdT is a useful ancillary test in diagnosis of B-ALL, especially when lym-phoblasts resemble mature lymphocytes on H&E-stained sections (Figs. 1A, B). However, TdT immunostain specificity for B-ALL is not clearly established in liver tissue, which can be problematic when only a few TdT-positive cells are identified (Figs. 1C, D). We aimed to determine whether a normal complement of hepatic immature B cells can be detected in adult and pediatric liver core biopsies, which must be recognized in a workup to exclude B-ALL.