Abstract
INTRODUCTION: Hypercalcaemia in intravascular large B-cell lymphoma (IVLBCL) is extremely rare, occurring more often in other non-Hodgkin's lymphomas (NHL). CASE DESCRIPTION: A 68-year-old man was admitted with a fever of unknown origin, mild disturbance of consciousness and respiratory failure. Laboratory findings showed hypercalcaemia with elevated parathyroid hormone-related protein (PTHrP) and decreased intact parathyroid hormone and 1,25-dihydroxyvitamin D. The patient was diagnosed with IVLBCL via random skin biopsy. Chemotherapy resulted in complete remission and normalised PTHrP levels. CONCLUSION: More than half of all cases of hypercalcaemia in NHL are not associated with PTHrP or 1,25-dihydroxyvitamin D, and the cause of the hypercalcaemia is unknown. However, PTHrP levels are elevated in most cases of IVLBCL with hypercalcaemia, which may present as humoral hypercalcaemia of malignancy. LEARNING POINTS: Intravascular large B-cell lymphoma, a rare, clinically aggressive type of B-cell non-Hodgkin's lymphoma, is prone to central nervous system disturbances, including altered consciousness.Hypercalcaemia, which causes impaired consciousness, is extremely rare in intravascular large B-cell lymphoma, occurring more often in other non-Hodgkin's lymphomas.Parathyroid hormone-related protein is elevated in most cases of intravascular large B-cell lymphoma with hypercalcaemia, which may present as humoral hypercalcaemia of malignancy.