Constipation as an Atypical Presentation of Hyperparathyroidism: A Case Report

BACKGROUND Hyperparathyroidism is a relatively rare endocrine disorder, albeit with increasing prevalence in the last years. While oftentimes clinically silent, it can lead to severe hypercalcemia, which is life-threatening and a medical emergency. Therefore, prompt diagnosis and treatment are essential, even in cases presenting with atypical symptoms. CASE REPORT We present a case of a patient with hyperparathyroidism presenting in the Emergency Department with only gastrointestinal symptoms. A 77-year-old woman presented with progressively more severe constipation and involuntary weight loss in the past 3 months. A computed tomography scan revealed calcified and non-calcified plaques in the lumen of the celiac trunk and superior mesenteric artery, along with diffusely distributed microcalcifications of the liver parenchyma. Colonoscopy could not be performed, due to increased and intractable fecal loading. After a laboratory examination revealed normochromic normocytic anemia and elevated ferritin and creatinine, further tests were ordered, and severe hypercalcemia, with serum calcium levels over 15 mg/dL, and parathormone levels over 1000 pg/mL were detected. Therefore, the diagnosis of primary hyperparathyroidism was established, attributed to a parathyroid gland adenoma visualized on computed tomography. The patient was subsequently referred to the Endocrinology Department. CONCLUSIONS With clinical awareness, patients presenting with unexplained gastrointestinal symptoms can be screened for and receive a diagnosis of hyperparathyroidism, by a prompt laboratory checkup of calcium and parathormone levels.