PTH and lymphoma: Other (non-CCAs) tumour biologies that also impair the blood calcium are represented by the ectopic PTH over-secretion (at the level of malignant cells, not by the parathyroid glands) or abnormal production of 1,25-dihydroxyvitamin D within malignancies (particularly hematologic neoplasia such as lymphomas, as similarly found in sarcoidosis and granulomatous diseases) that hold the enzymatic equipment for this final step of 25-hydroxyvitamin D activation (calcitriol-induced hypercalcaemia).