Primary hyperparathyroidism presenting as acute pancreatitis: An institutional experience with review of the literature.

Background: Acute pancreatitis (AP) presenting as an initial manifestation of primary hyperparathyroidism (PHPT) is uncommon, and its timely diagnosis is crucial in preventing recurrent attacks of pancreatitis.

Aim: To determine the clinical, biochemical, and radiological profile of PHPT patients presenting as AP.

Methods: This is a retrospective observational study, 51 consecutive patients admitted with the diagnosis of PHPT during January 2010 and October 2021 at a tertiary care hospital in Puducherry, India was included. The diagnosis of AP was established in the presence of at least two of the three following features: abdominal pain, levels of serum amylase or lipase greater than three times the normal, and characteristic features at abdominal imaging.

Results: Out of the 51 consecutive patients with PHPT, twelve (23.52%) had pancreatitis [5 (9.80%) AP, seven (13.72%) chronic pancreatitis (CP)]. PHPT with AP (PHPT-AP) was more common among males with the presentation at a younger age (35.20 ± 16.11 vs 49.23 ± 14.80 years, P = 0.05) and lower plasma intact parathyroid hormone (iPTH) levels [125 (80.55-178.65) vs 519.80 (149-1649.55, P = 0.01)] compared to PHPT without pancreatitis (PHPT-NP). The mean serum calcium levels were similar in both PHPT-AP and PHPT-NP groups [(11.66 ± 1.15 mg/dL) vs (12.46 ± 1.71 mg/dL), P = 0.32]. PHPT-AP also presented with more gastrointestinal symptoms like abdominal pain, nausea, and vomiting with lesser skeletal and renal manifestations as compared to patients with PHPT-NP.

Conclusion: AP can be the only presenting feature of PHPT. Normal or higher serum calcium levels during AP should always draw attention towards endocrine causes like PHPT.