An Unusual Cause Of Severe Refractory Hypercalcemia
Hypercalcemia is commonly caused by hyperparathyroidism in the outpatient setting and is mostly asymptomatic. However, hypercalcemia in the inpatient setting is usually more severe and frequently associated with malignancy.
A 36 year old AAM was admitted to our facility with generalized weakness for three weeks. This was associated with nausea and vomiting, loss of appetite and constipation. At presentation to the hospital, his vital signs were normal. On exam, the patient was obese and appeared dry but there were no other remarkable findings.
At the emergency room he was found to be severely hypercalcemic at 16.7 mg/dL (8.8‐10.2) and ionized calcium 2.16 mmol/L (0.89‐1.21). Additionally, creatinine was 5.1 mg/dL, WBC 16.6k/mm3, platelet 147k/mm3and normal hemoglobin. Aggressive hydration was started along with calcitonin and eventually pamidronate.
Parathyroid hormone and 1,25(OH)2vitamin D levels were low. Parathyroid hormone related peptide (PTH‐rp), serum protein electrophoresis, angiotensin converting enzyme (ACE) level, and thyroid stimulating hormone (TSH) were normal. HIV 1 and 2, urine histoplasma antigen, and TB Quantiferon tests were negative. CT was performed which showed only mild splenomegaly and scattered small lymphadenopathy in the para‐ortic area which were not accessible for biopsy. Liver, spleen and bone scan were done which were all negative.
After some initial improvement, the calcium level started to rapidly rise again and the patient became lethargic. Dialysis was initiated. Due to concerns about malignancy, a bone marrow biopsy was performed. Results eventually showed T cell leukemia/lymphoma and serology was positive for human T cell leukemia virus type 1 (HTLV‐1). Intensive chemotherapy was started and on the fourth day of chemotherapy, the calcium level reached 8.1and the renal function normalized.
Adult onset T cell leukemia lymphoma (ATLL) is associated with HTLV‐1 infection.
Only 2% of people infected with HTLV‐1 develop ATLL. Clinically patients present with leukemia or lymphoma and severe hypercalcemia. The mechanism of hypercalcemia has been described as increased bone resorption mediated by PTH‐rp or lymphokines and tumor necrosis factor. In our patient, the PTH‐rp was normal with low 1,25(OH)2vitamin D levels, supporting the role of cytokines as the cause of HTLV‐1 associated hypercalcemia.
The leading cause of severe hypercalcemia in malignancy is ectopic tumor production of PTH‐rp and the sequelae can be life‐threatening. When PTH‐rp is normal and no solid tumor is obvious, one should consider hematologic causes of hypercalcemia like ATLL. Checking for HTLV‐1 serology should be considered in these patients.
To cite this abstract:Bekele 2, Lim T. An Unusual Cause of Severe Refractory Hypercalcemia. Abstract published at Hospital Medicine 2014, March 24-27, Las Vegas, Nev. Abstract 344. Journal of Hospital Medicine. 2014; 9 (suppl 2). https://www.shmabstracts.com/abstract/an-unusual-cause-of-severe-refractory-hypercalcemia/. Accessed July 23, 2019.