MON-319 A Young Woman with Familial Isolated Primary Hyperparathyroidism Due to Parathyroid Adenoma and Atrophic Gastritis

Abstract

Background: High levels of gastrin and parathyroid hormone (PTH) can coexist outside the multiple endocrine neoplasia (MEN) kindred syndromes. There is significant non-causal association between chronic autoimmune atrophic gastritis (CAAG) and primary hyperparathyroidism (PHPT). Prevalence of PHPT is increased in patients with CAAG (8.4 vs 1–3%, general population).1,2 These studies excluded people with familial PHPT, MEN1 syndrome, those on proton pump inhibitors, H. pylori infection and renal failure. Some studies show an association between gastric carcinoid type 1 tumor (GC-1) and PHPT.3 No data is available on association between hypergastrinemia, gastritis and familial isolated HPT (FIHPT) Case: A 37-year-old female with hypothyroidism due to Hashimoto’s thyroiditis and premature ovarian insufficiency was incidentally found to have hypercalcemia with total calcium of 10.8 mg/dL (8.9–10.4), ionized calcium 1.4 mg/dL (1.14–1.33), 24 hour urine calcium of 0.252 g/d (0.032–0.368), urine creatinine 0.56 g/24hr (0.78–2.31), urine volume 1650 mL. 25 OH Vitamin D was low at 17 pg/ml. She also had elevated chromogranin A level at 541 ng/mL (0–95), gastrin level of 1522 pg/mL (0–100) and Vitamin B12 level of 299 pg/mL (> 201 acceptable), negative intrinsic factor and antiovarian antibody. There is a strong family history of primary hyperparathyroidism in mother and sister and hypercalcemia in brother and niece (unknown workup). Parathyroid scan showed ectopic parathyroid adenoma, with mild focal uptake a few centimeters inferior to the lower pole of the right thyroid gland. Bone density scan showed osteopenia at L1- L4 lumbar spine with T score -2.1 and BMD of 0.924 g/cm2. Genetic test was negative for CASR, CDC73, CDKN1B, MEN1, RET amplified by long-range PCR and sequenced by Pacific Biosciences SMRT. Upper GI endoscopy with gastric biopsy showed severe chronic atrophic gastritis with extensive intestinal metaplasia associated with diffuse neuroendocrine cell hyperplasia within the crypts. She was diagnosed with familial isolated primary hyperparathyroidism with chronic atrophic gastritis. Conclusion: As far as we know, there are no reported cases documenting chronic atrophic gastritis occurring with familial isolated primary hyperparathyroidism. This case highlights that in patients with FIHPT, hypergastrinemia and gastritis can occur independent of MEN -1 syndrome.