SAT180 Comparison Between Sporadic Primary Hyperparathyroidism And Multiple Endocrine Neoplasia Type 1 (MEN1)-Associated Primary Hyperparathyroidism: A Retrospective Analysis Of The Indian PHPT Registry

Disclosure: S. Bhadada: None. A.M. Chakraborty: None. P. Kumari: None. R. Pal: None. A. Sood: None. D. Dahiya: None. S.D. Rao: None. Introduction: Multiple endocrine neoplasia type 1 (MEN1)-associated tumours are located in parathyroid, pituitary and pancreatoduodenal locations. Though heterogenous, the most consistent presentation of MEN1 is primary hyperparathyroidism (PHPT) seen in almost 100% of cases. Comparisons between sporadic and MEN1 PHPT patients are sparse in the literature. Objective: To retrospectively compare the demography, clinical manifestations, management, and outcome of sporadic PHPT and MEN1-associated PHPT patients. Design and setting: A registry-based (www.indianphptregistry.com) retrospective cohort study from a tertiary care hospital in North India. Methods and patients: The medical records and clinical data of sporadic PHPT patients and MEN1-associated PHPT patients registered in the Indian PHPT registry were analysed. Result: A total of 616 PHPT patients have been registered in the electronic registry, 72 of whom (11.68%) were MEN1-associated PHPT. The mean age of sporadic PHPT patients was 43.4 ± 14.3, whereas MEN1-associated PHPT was 35.8 ± 13.5 years (p<0.05). Among MEN1-associated PHPT cases, 66 (90%) were index cases at the time of presentation, and the rest were detected on family screening. For both sporadic PHPT and MEN1-associated PHPT, the most common presenting symptom was bone pain, followed by renal stone disease. Sporadic PHPT and MEN1 PHPT both had comparable mean calcium (11.9 ± 1.5 vs 11.9 ± 1.6 mg/dl), mean phosphate (2.7 ± 1 vs 2.58 ± 0.7 mg/dl), median PTH (314; IQR 161-984 pg/ml vs 292; IQR 180-818 pg/ml) level at presentation. Median 25-hydroxyvitamin D level was 19.3; IQR 10.4-30.4 ng/dl, and 15; IQR 8.1 – 25.1 ng/dl (p<0.05) for sporadic PHPT and MEN1-associated PHPT respectively. Multiglandular disease was common in MEN1-associated PHPT (40.2%) compared to sporadic cases (3%). Median tumour weight was higher in sporadic cases (2.5; IQR 0.8- 7.3 gm) compared to MEN1 cases (1.9; IQR 1.08 – 4.05 gm). Ultrasound neck and Sesta-MIBI concordance rate among sporadic cases was 57%, whereas MEN1 cases were 70.8%. Median post-surgery decline in PTH and calcium was more in the case of sporadic PHPT in comparison to MEN1-associated PHPT 84.81% vs 46.7% and 23.4% vs 16.59 % respectively (p<0.05). Discussion: MEN1-associated PHPT patients presented at an earlier age than sporadic cases. There was no statistical difference in PTH, calcium or phosphate levels between the two cohorts, but 25-hydroxyvitamin D levels were lower in MEN1-associated PHPT. Localisation was better in the case of the MEN-1 cohort as per as the Sesta-MIBI and USG concordance was concerned. Postoperative fall of PTH and calcium was more in sporadic cases than in MEN1 cases. Presentation: Saturday, June 17, 2023