Secondary Hyperparathyroidism in Primary Intestinal Lymphangiectasia: A Report of Four Cases.

Primary intestinal lymphangiectasia (PIL) is a rare disease characterized by the loss of lymphatic fluid in the intestinal lumen and is a known cause of protein-losing enteropathy (PLE). Although uncommon, few cases of secondary hyperparathyroidism (SHPT) have been reported in patients with PIL. This study summarizes the characteristics of four cases diagnosed with PIL. Notably, all cases were confirmed to have hyperparathyroidism secondary to vitamin D deficiency and hypocalcemia. Recurrent diarrhea and limb convulsions were also observed in all patients, with one patient diagnosed with osteoporosis. Simultaneously, hypomagnesemia was detected in three cases. Treatment with vitamin D and calcium supplements relieved symptoms, elevated serum calcium levels, and decreased parathyroid hormone (PTH) levels. In patients with PIL, evaluation of 25-hydroxyvitamin D, calcium, and PTH levels is crucial. Bone diseases should be considered in patients with SHPT, and appropriate vitamin D3 and calcium supplementation is highly recommended.