Spontaneous tumour lysis syndrome in chronic lymphocytic leukaemia: an unanticipated complication of an undiagnosed disease.

Spontaneous tumour lysis syndrome (STLS) is a rare oncological emergency characterised by the spontaneous destruction of tumour cells in the absence of chemotherapy, with the release of large amounts of intracellular ions and metabolic products leading to organ damage and at times death. In chronic lymphocytic leukaemia (CLL), historically, tumour lysis syndrome has been rarely observed owing to low rate of proliferation and slow response to chemotherapy. We report a rare case of STLS in underlying undiagnosed CLL.