Occult intravascular large B-cell lymphoma presenting as postoperative thrombotic microangiopathy: a case report

CC BY-NC-ND 4.0 CASE REPORT Occult intravascular large B-cell lymphoma presenting as postoperative thrombotic microangiopathy: a case report WK Lam, MB, BS1; Edmond SK Ma, FHKCPath, MD2; SY Kong, FHKCP, FHKAM (Medicine)3; SF Yip, FHKCPath, FHKCP1 1 Department of Clinical Pathology, Tuen Mun Hospital, Hong Kong SAR, China 2 Clinical Laboratory, Hong Kong Sanatorium [and] Hospital, Hong Kong SAR, China 3 Department of Medicine and Geriatrics, Pok Oi Hospital, Hong Kong SAR, China Corresponding author: Blood tests showed a leukoerythroblastic blood picture and no circulating abnormal cells, and acute hepatic and renal failure with markedly elevated lactate dehydrogenase level (Table). There was severe reduction in ADAMTS13 activity to 5% with ADAMTS13 antigen level moderately reduced to 215 ng/mL (reference range: 430-970) and autoantibody level at 2.5 units/mL (negative: [lesser than]15). Autoantibodies against ADAMTS13 may also play a role in pathogenesis, leading to platelet activation and thrombotic microangiopathy.2 In our case, ADAMTS13 activity was markedly reduced at 5%, unusually low for malignancy-associated TTP (median ADAMTS13 activity: 50%).3 Some secondary TTP cases have been reported with markedly reduced ADAMTS13 activity4 but the significance is uncertain.