Primary Hyperparathyroidism Associated with Primary Antiphospholipid Syndrome and Pulmonary Involvement

Primary hyperparathyroidism (PHPT) and antiphospholipid syndrome (APS) are distinct disorders, with their coexistence being exceptionally rare. The case of a 37-year-old male diagnosed with PHPT who was also found to have external jugular vein thrombosis is described. On evaluation, the patient was diagnosed with primary APS, complicated by pulmonary arterial hypertension and interstitial lung disease. The patient underwent successful parathyroidectomy, leading to normalization of calcium and parathyroid hormone levels, while anticoagulation with rivaroxaban was initiated for APSrelated thrombosis. Though severe hypercalcemia is known to be associated with thrombosis, this patient had mild hypercalcemia and primary APS-related thrombosis, which is exceptionally rare. Cite this article as: Alam E, Jasti P, Bhat MH, Baba MS, Hamdani ZF, Dutta P. Primary hyperparathyroidism associated with primary antiphospholipid syndrome and pulmonary involvement. Endocrinol Res Pract. 2026;30(1):68-71.