Calcium oxalate crystals in the bone marrow

Abstract

A 37-year-old female presented with a 3-day history of migratory arthralgias, fever, vomiting and mouth ulcers. Comorbidity included end stage renal disease due to obstructive uropathy and chronic liver disease for 4 years. On examination there were cushingoid facies and right inguinal lymphadenopathy. She was drowsy and had a temperature of 39 C. A full blood count showed haemoglobin: 86 g/l, haematocrit 0AE257 l/l, mean cell volume 88AE6 fl, mean cell haemoglobin 26 pg, white cell count 2AE0 · 10/l and platelets 62 · 10/l. A blood film showed pancytopenia with anisocytosis, target cells, polychromasia and nucleated red cells. A subsequent bone marrow aspirate was hypocellular and dilute with long needle like crystals. These were apparent even on an unstained bone marrow smear (top left) and showed birefringence in polarized light on haematoxylin and eosin (H&E)-stained sections (top right) and on a reticulin stain (bottom left). Sections of a trephine biopsy specimen stained with H&E showed variably sized rosettes of needle-like crystals (bottom right). Based on the characteristic appearance of crystals in the bone marrow associated with renal failure a diagnosis of primary hyperoxaluria (oxalosis) was made. This is a rare metabolic disorder characterized by excessive excretion of oxalic acid in urine causing recurrent renal stones with subsequent renal failure.