A 64-year-old man was brought to emergency department (ED) by his family for generalized weakness and fatigue leading to multiple falls in the past week. Ten months earlier, he was diagnosed simultaneously with stage II anterior mediastinal classic Hodgkin lymphoma (cHL) and kappa light chain multiple myeloma (MM) with associated acute kidney injury (AKI). Serum creatinine was elevated from a baseline of 1.0 mg/dL to 5.6 mg/dL. Patient then underwent 4 cycles of chemotherapy with bortezomib, cyclophosphamide, and dexamethasone (CyBorD). With this, kidney function improved and serum creatinine decreased to 2.3 mg/dL and kappa light chain level dropped from 9152 to 89 mg/L. Shortly after, he moved and did not follow up with his oncologist until this ED visit, where he had multiple laboratory abnormalities as shown below:
- Serum total calcium 13.3 mg/d
- Ionized calcium 1.8 mmol/L (normal 1.15-1.35 mmol/L)
- Hemoglobin 8.0 g/dL
- White blood cell count 10.41 x 109/L
- Serum creatinine 3.39 mg/dL
- Blood urea nitrogen 57 mg/dL
- Urine protein-to-creatinine ratio 1.5 g/g (urinalysis negative for blood or protein).
A chest X-ray showed a right mediastinal mass (Figure 1). Computed tomography (CT) of the chest revealed a marked interval increase in the size of the mediastinal mass measuring 9.6 x 6.5 x 3.8 cm suggesting progression of lymphoma.
Further work up for hypercalcemia showed:
- Kappa light chain 102 mg/dL
- Intact PTH 14 (normal 18.4-80.1 pg/mL)
- PTH-related protein 13 (normal 11-20 pg/mL)
- 25-hydroxyvitamin D level 32 ng/mL (normal 30-140 ng/mL)
- 1, 25-dihydroxyvitamin D total level 120 pg/mL (normal 18-72 pg/mL)