Lactic dehydrogenase estimation in haematological malignancies.

Earlier studies have indicated a role for serum lactic dehydrogenase (LDH) in haematological and other malignancies. As this is still not a routine test in many units, its value has been re-examined in a retrospective analysis of serum LDH levels in 278 patients with haematological malignancies managed in a single unit. Abnormal levels at diagnosis were found in 42% of these disorders; yet analysis of over 23,000 routine requests for a biochemical screen showed only 4% with an abnormal LDH level. The estimation was also valuable in follow-up of those haematological patients, with rising levels often indicating progressive or relapsing disease even in cases which had shown a normal LDH at diagnosis.