SAT-766 - Silicone Leak Followed by Activated Tuberculosis as A Cause of Calcitriol-Mediated Hypercalcemia

Extrarenal production of 1,25-dihydroxyvitamin D by activated macrophages is a recognized cause of hypercalcemia in granulomatous disease. This mechanism is most often associated with sarcoidosis, infection, and lymphoproliferative disease. Foreign-body reactions represent an underrecognized etiology. Silicone can provoke chronic granulomatous inflammation capable of dysregulated vitamin D activation, and the resulting clinical presentation may resemble lymphoma or chronic infection, requiring careful assessment.

Case:
An 81-year-old woman with remote silicone breast implants presented with weakness and constipation. She was found to have hypercalcemia to 14.1 mg/dL with suppressed parathyroid hormone and elevated 1,25-dihydroxyvitamin D. Imaging demonstrated bilateral axillary lymphadenopathy with punctate calcifications and ultrasound “snowstorm” artifact suggestive of silicone migration and subsequent calcification. Flow cytometry identified a small CD5-positive clonal B-cell population, raising concern for lymphoproliferative disease. Core biopsy of a common iliac lymph node instead demonstrated a granulomatous reaction with vacuolated histiocytes and multinucleated giant cells consistent with silicone, without evidence of malignancy or infection.
Given ongoing diagnostic uncertainty, glucocorticoids were withheld. The patient was treated with intravenous fluids, calcitonin, and dose-adjusted zoledronic acid, resulting in normalization of calcium. She remained stable until three years later, when she re-presented with new onset cough and weight loss as well as recurrent hypercalcemia. Thoracoscopic biopsy of a lymphocyte-predominant pleural effusion revealed necrotizing granulomas with acid-fast bacilli confirming active tuberculosis as a new, additional etiology of calcitriol-mediated hypercalcemia.

Conclusion:
Silicone-induced granulomatous inflammation is an uncommon but important cause of calcitriol-mediated hypercalcemia. History and tissue sampling are essential for diagnosis, and recurrent hypercalcemia should prompt reassessment for additional processes. This case highlights the need to consider foreign-body reactions in patients with prior silicone implants and emphasizes that distinct conditions may arise sequentially in the same patient.

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