Hypercalcaemia of malignancy: a case of vitamin-D-mediated hypercalcaemia in lymphoma.

Hypercalcaemia of malignancy (HCM) is a paraneoplastic syndrome that often portends a poor prognosis. We present an extremely rare (<1%) case of HCM due to extrarenal calcitriol (1,25-(OH)D) production in a patient with splenic marginal zone lymphoma. A man in his 80s presented with a 3-week history of fatigue, unsteadiness and abdominal pain, and new findings of anaemia, kidney injury and hypercalcaemia.

Dapsone-induced methemoglobinemia and hemolysis in a woman without G6PD deficiency presenting with idiopathic urticaria.

Background: The appearance of bite cells associated with methemoglobinemia can be caused by oxidizing drugs such as dapsone in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency or high drug serum levels. Bite cells are often pathognomonic for oxidant injury in patients with G6PD deficiency and suggest active hemolysis.

Case Presentation: We report a case of a woman with no prior history of G6PD deficiency who presented with anemia, methemoglobinemia and bite cells on peripheral blood smear after dapsone therapy for new onset idiopathic urticaria.