[Hypercalcemia in an 81-year-old female patient].

In the investigation of hypercalcemia of an 81-year-old female patient, the typical laboratory value constellation of primary hyperparathyroidism (pHPT) emerged. The staged imaging diagnostics with sonography of the neck, sestamibi parathyroid gland scintigraphy and C‑11-methionine positron emission tomography-computed tomography (PET CT) resulted in negative or inconspicuous findings for all procedures. The exploratory surgical resection of two hyperplastic epithelial bodies led to a normalization of calcium levels. Inconspicuous imaging findings do not exclude the diagnosis of pHPT.