An unexpected cause of severe and refractory PTH-independent hypercalcemia: case report and literature review

Introduction: Hypercalcemia is a common condition in the internal medicine practice. Sometimes the cause is not readily apparent, so extensive investigation is appropriate. Here we report an unexpected cause for hypercalcemia in an elderly woman. Case report: The case of an 82-years old woman with PTH-independent hypercalcemia, lymphocytosis, normal serum 1,25 (OH)vitamin D levels, and low serum PTHrp levels, is described. Medical history and complementary investigation was unremarkable, except for extensive and symmetric increased glucose metabolism in the glutei regions, as measured by whole body 18F-FDG PET-CT.  This led to the acknowledgment, by her sister, of intramuscular methylmethacrylate injections, for cosmetic purpose, five years before presentation, which was confirmed by muscle biopsy. Low calcium intake, parenteral bisphosphonates, calcitonin, and glucocorticoids were used to control serum calcium levels. Conclusion and Relevance: Methylmethacrylate injections, used cosmetically, are a new cause for hypercalcemia, even after many years. Hypercalcemia was probably due to calcitriol overproduction, in foreign body granulomas. Persistent reactive lymphocytosis could be a clue for this inflammatory cause of hypercalcemia.