Hypercalcemia associated with mineral oil-induced sclerosing paraffinomas

Granuloma-forming diseases such as sarcoidosis are associated with extrarenal synthesis of 1,25-dihydroxyvitamin D [1,25(OH)₂D]. We describe a case of extensive skin lesions associated with mineral oil injections in which we provide evidence for cutaneous granuloma synthesis of 1,25(OH)₂D in the pathogenesis of the patient's hypercalcemia. Analysis of expression of the 25(OH)D-1a-hydroxylase (1-a OHase [CYP27b1]) was carried out by immunohistochemical analysis of involved skin. In involved skin, expression of CYP27b1 was found in the dermis, where it is not normally expressed. Successful management of hypercalcemia was achieved with glucocorticoids. Hypercalcemia associated with mineral oil induced skin lesions is likely driven by unregulated expression of CYP27b1 by inflammatory monocytes and macrophages infiltrating the dermis