Advanced Lymphoblastic Lymphoma, NOS in Leukaemic Phase Presenting With Sudden and Fatal CNS Haemorrhage.

B/T-lymphoblastic lymphoma (LBL), not otherwise specified (NOS), is a rare precursor lymphoid neoplasm that exists along a biological spectrum with acute lymphoblastic leukaemia (ALL). Although traditionally distinguished by the extent of bone marrow involvement, this separation becomes increasingly blurred in advanced or leukaemic presentations. Central nervous system (CNS) haemorrhage is a recognised but uncommon complication of acute leukaemia and is exceptionally rare as an initial manifestation within the LBL-ALL spectrum. We report a 58-year-old man with a 6-month history of recurrent constitutional symptoms and anaemia, partially relieved by supportive therapy, a clinical course more suggestive of an LBL than de novo ALL. On admission, he was febrile, anaemic, thrombocytopenic and hypoxic, with hepatomegaly and mild lymphadenopathy, and deteriorated rapidly, dying within 24 h. Post-mortem examination revealed a hypercellular bone marrow extensively replaced by lymphoblasts, widespread multiorgan infiltration and a large intracerebral haemorrhage with ventricular and subarachnoid extension. Histological examination demonstrated leukostasis, perivascular lymphoblast infiltration, leukaemic nodules and areas of both acute and chronic haemorrhage. The chronic clinical course, limited nodal disease and extensive marrow and extranodal involvement support an interpretation of advanced LBL, NOS in the leukaemic phase. This presentation also highlights the substantial biological overlap with ALL. This case highlights the risk of catastrophic CNS haemorrhage across the LBL-ALL spectrum and reinforces the need for vigilance, timely diagnostics and the enduring value of autopsy in clarifying unexpected deaths.