Hypercalcemia associated with isolated bone marrow sarcoidosis in a patient with underlying monoclonal gammopathy of undetermined significance: case report and review of literature.

John Gubatan,John Vanderpool,Xiaohui Wang,Abner Louissaint,Anuj Mahindra

doi:10.1186/s40364-016-0072-5

Abstract

BackgroundBone marrow sarcoidosis is extremely rare. The association between sarcoidosis and lymphoproliferative disorders has been previously speculated, although the diagnosis of sarcoidosis often precedes any hematological derangements.Case presentationHere, we report for the first time, a case of a 57-year-old Caucasian woman with a previous diagnosis of monoclonal gammopathy of undetermined significance (MGUS) developing hypercalcemia and renal failure with workup notable for isolated bone marrow sarcoidosis and not multiple myeloma as expected. The patient was successfully managed with prednisone taper therapy with resolution of her hypercalcemia and repeat bone marrow biopsies demonstrating resolving granulomas.ConclusionsOur case illustrates the diagnostic challenges associated with bone marrow sarcoidosis and suggest that chronic immune stimulation in the bone marrow in the setting of MGUS may be associated with the development of localized sarcoidosis. The long term consequences of steroid therapy targeting sarcoidosis in this patient with underlying MGUS remain unknown. Greater surveillance and closer followup is planned in light of the increased risk of malignant transformation of MGUS into multiple myeloma in the setting of bone marrow sarcoidosis.

Highlights

Our case illustrates the diagnostic challenges associated with bone marrow sarcoidosis and suggest that chronic immune stimulation in the bone marrow in the setting of monoclonal gammopathy of undetermined significance (MGUS) may be associated with the development of localized sarcoidosis
Greater surveillance and closer followup is planned in light of the increased risk of malignant transformation of MGUS into multiple myeloma in the setting of bone marrow sarcoidosis
We report an unusual case of a patient with four-year history of monoclonal gammopathy of undetermined significance (MGUS) preceding the diagnosis of isolated bone marrow sarcoidosis presenting as hypercalcemia

Summary

Conclusions

Isolated bone marrow sarcoidosis is rare and can be a diagnostic challenge. The clinical suspicion for sarcoidosis should be raised in patients with underlying hematologic disorders or malignancies. Due to the rarity of the condition, long terms outcomes in such patients are unclear. Surveillance and regular follow-up is planned in view of the possibility of progression to multiple myeloma or another lymphoproliferative disorder

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