An extremely rare case of calcinosis cutis in human Cushing's disease.

Summary: Cushing's disease or pituitary adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome is considered a rare condition. It is caused by hypersecretion of the ACTH by a pituitary adenoma that ultimately induces endogenous hypercortisolism by stimulating the adrenal glands. It is responsible for significant morbidity and mortality. The clinical signs and symptoms of hypercortisolism are usually common and non-specific including obesity, moon face, hypertension, hirsutism and facial plethora. The association between Cushing's disease and calcinosis cutis which is defined as dystrophic calcium deposition in the skin and subcutaneous tissues is extremely rare. To the best of our knowledge, it has never been described previously in humans, probably like a symptom or complication of chronic and severe hypercortisolism. In this paper, we report a case of a 30-year-old female diagnosed with Cushing's disease and presented bilateral leg's calcinosis cutis complicated with ulceration. The evolution was favorable and the complete cicatrization was obtained 12 months following the suppression of systemic glucocorticoid excess.

Learning Points: Calcinosis cutis is common in autoimmune connective diseases. However, to our knowledge, it has never been reported in humans with Cushing's disease. Given the rarity of this association, the diagnostic approach to calcinosis cutis must exclude the other etiologies. Calcinosis cutis is challenging to treat with no gold standard therapy. In our case, the use of the combination of colchicine and bisphosphonates does not significantly improve the patient's outcomes. In fact, we suppose that without treating the endogenous hypercortisolism, the calcinosis cutis will not resolve.