Splenic sarcoidosis without focal nodularity: a case of 1,25-dihydroxyvitamin D-mediated hypercalcemia localized with FDG PET/CT.
OBJECTIVE
To report an uncommon cause of 1,25-dihydroxyvitamin D (1,25[OH]2D)-mediated hypercalcemia associated with splenic sarcoidosis and illustrate the evaluation and potential role of fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in such patients.


METHODS
We present detailed clinical features, laboratory results, imaging results, and pathology results for this rare entity, discuss evaluation and management options, and review previous literature.


RESULTS
A 65-year-old male presented with symptomatic hypercalcemia, with a serum calcium level of 14.1 mg/dL 3 months after being initiated on ergocalciferol for vitamin D deficiency. He was found to have a suppressed parathyroid hormone level, normal 25-hydroxyvitamin D (25[OH]D) level, and elevated 1,25(OH)2D level. Extensive evaluation did not yield a definitive diagnosis. His calcium levels normalized and symptoms resolved on prednisone then recurred when prednisone was discontinued. FDG PET/CT showed intense uptake in the spleen. Splenectomy was performed, which resulted in resolution of hypercalcemia and yielded a diagnosis of splenic sarcoidosis.


CONCLUSIONS
Splenic sarcoidosis causing hypercalcemia has been rarely reported. Our case is unique in that the spleen lacked typical focal nodularity on cross-sectional CT imaging, which is expected in sarcoid involvement of the spleen. Our case adds to an emerging literature documenting the potential value of FDG PET/CT in localizing otherwise occult 1,25(OH)2D-mediated hypercalcemia.
Department of Endocrinology, Charlie Norwood VA Medical Center Section of Endocrinology Diabetes and Metabolism, Georgia Regents University.
Benjamin A
BA
Dennis
Department of Pathology, Charlie Norwood VA Medical Center Department of Pathology, Georgia Regents University, Augusta, Georgia.
Ryan P
RP
Jajosky
Department of Endocrinology, Charlie Norwood VA Medical Center Section of Endocrinology Diabetes and Metabolism, Georgia Regents University.
René J
RJ
Harper