Kidney Week

Abstract: TH-PO176

A Rare Case of Hypercalcemia in Primary Hypoparathyroidism due to Multiple Myeloma

Session Information

• CKD-MBD: Targets and Outcomes
  November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 402 Bone and Mineral Metabolism: Clinical

Authors

• Tahir, Muhammad Khalid, Richmond University Medical Center, Staten Island, New York, United States

Muhammad Khalid Tahir,

• Mahtani, Arun Umesh, Richmond University Medical Center, Staten Island, New York, United States

Arun Umesh Mahtani,

• Grigos, Angela, Richmond University Medical Center, Staten Island, New York, United States

Angela Grigos,

• Ebrahimi, Farhang, Richmond University Medical Center, Staten Island, New York, United States

Farhang Ebrahimi,

Introduction

- Incidence and prevalence of primary hypoparathyroidism (PHPT) in the United States: 0.08 and 37 per 100,000 person-years, respectively.¹Seen in females above 45 years.
- The most common cause of PHPT is iatrogenic.²
- Hypercalcemia can also occur iatrogenically due to supplementation.³
- Several cases linking primary hyperparathyroidism and multiple myeloma (MM) have been reported.⁴
- To the author's knowledge, this is the first case of a patient having PHPT with concomitant MM.

Case Description

- A 50-year-old-male with a history of chronic kidney disease stage 3 (CKD stage 3), primary hypoparathyroidism since 1997 on calcium and calcitriol supplementation, and gastroesophageal reflux disease (GERD) presented with: lower back pain (LBP), increased urinary frequency, and chronic cough for 1 month.
- Physical examination: LBP exacerbated with movement.
- Labs: serum calcium of 17.5 mg/dL, serum sodium of 129 mmol/L, serum potassium of 5.2 mmol/L, total protein of 10.4 g/dL, albumin of 4 g/dL, and intact PTH of < 6.3 pg/mL.
- Free Kappa/Lambda light chains: 9.4/1369.7. Elevated IgA levels: 3138.4.
- SPECT showed no suspicious areas of MM.
- Bone marrow biopsy: 41% of monoclonal intracellular lambda positive plasma cell (kappa to lambda ratio: < 0.01). Positive for cytoplasmic heavy chain IgA, partially positive for cluster of differentiation (CD)117, aberrantly positive for CD27, and negative for CD56.
- Treatment: intravenous fluids, calcitonin, pamidronate, and chemotherapy.

Discussion

- 28% of patients with MM are hypercalcemic.⁵
- PTH may be an inducer of MM through signaling pathways involving IL-6.⁶
- First reported case of primary hypoparathyroidism in a patient with concomitant MM.
- Large-scale studies needed to understand the relationship between PTH and MM.
- Etiology of hypercalcemia in primary hypoparathyroidism should always be investigated.

Bone marrow biopsy showing plasma cells