Endocrine Abstracts

Background: Calcinosis cutis is a rare manifestation characterized by calcium deposits in the skin and subcutaneous tissues, mostly found in auto-immune diseases. A case of calcinosis cutis (on the vertex and the face) associated to hyperparathyroidism is presented. We discuss the etiology, diagnosis and management of this rare condition, along with a short review of the literature

Case presentation: We report a case of calcinosis cutis with primary hyperparathyroidism. A 77 year-old woman initially presented a rash associated with a severe pruritus responsible for significant impact on quality of life. The rash was only located on the vertex, the face and the ears and associated to externalization of small grains and filaments. She also presented a hypercalcemia due to primary hyperparathyroidism. It was a moderate hypercalcemia (average 2.85 mmol/l) with PTH 100 ng/l (N 15-65). The renal assessment was normal and the bone mineral density (BMD) was subnormal (femoral neck Tscore -1.7 and lumbar Tscore -2.1). The morphological assessment found an ectopic parathyroid adenoma of 15 mm near the thyroid cartilage. The patient had a cutaneaous biopsy of the calcinosis and the anatomopathological analysis did not found any specific element of calcinosis. The analysis of the small grains stated they were calcium grains\. No auto-immune or infectious cause was found (ANCA, ANA, anti Sm, anti-RNP, anti SSA SSB, HIV, HBV and HCV serologies, and parasitological stool examination). We assumed that it was a cutaneous manifestation of the primary hyperparathyroidism; although it is extremely rare. We reported less than 5 cases in the literature and most of them had calcinosis cutis due to secondary hyperparathyroidism; only one case had primary hyperparathyrodism. By performing a neck surgery to remove the parathyroid adenoma, the calcemia normalized immediately while it took around 3 months to see a favorable evolution of the calcinosis.

Conclusion: Although, calcinosis cutis is rarely associated to primary hyperparathyroidism, it should be evoked in patients with a negative auto-immune or infectious assessment, with a hypercalcemia due to hyperparathyroidism and a rash. If the diagnosis of calcinosis cutis is confirmed in these patients, the surgery of the parathyroid adenoma enables a favorable, although slow, evolution.