A Case of Megaloblastic Anaemia Complicated with Extra-Pulmonary Tuberculosis

Megaloblastic anaemia is known to cause elevated lactate dehydrogenase (LDH) levels due to increased cell turn over with ineffective erythropoiesis in the bone marrow, a laboratory parameter which can help in the diagnosis and monitoring the response to treatment with vitamin B12 and folate as well. Serum LDH level can get significantly elevated in many other non- neoplastic and neoplastic conditions as well, such as metastatic cancers, infections, haematological malignancies including lymphomas and conditions with haemolysis. Elevated LDH is considered as an independent predictor of mortality and a marker of major complications in hospitalized patients [1].

This case is about a young man, a vegan who presented with features of megaloblastic anaemia,generalized lymphadenopathy, constitutional symptoms and a very high LDH level mimicking a diagnostic possibility of a high grade lymphoma, ultimately confirmed to have megaloblastic anaemia and tuberculous lymphadenitis, the latter was an unexpected finding of the lymph node biopsy done to exclude a lymphoma.

His significantly high LDH level at diagnosis which declined dramatically in response to vitamin B12 replacement therapy, can be used as a supportive diagnostic tool and also to monitor the response to therapy in megaloblastic anaemia.