[Unexpected Postoperative Diagnosis of Parathyroid Carcinoma].

Unexpected Postoperative Diagnosis of Parathyroid Carcinoma Parathyroid carcinoma is a rare endocrine malignancy. It typically presents itself with similar clinical features as seen in patients with primary hyperparathyroidism caused by a parathyroid adenoma. Due to overlapping clinical manifestations, imaging findings and pathological characteristics, the differentiation between benign and malignant parathyroid disease poses a diagnostic challenge, especially prior to surgery. We report the case of a 67-year-old male who presented with symptomatic hypercalcemia and primary hyperparathyroidism. During resection of the enlarged parathyroid gland, suspicious macroscopic features were noticed and the histopathology finding confirmed the malignancy. Parathyroid carcinoma is rarely diagnosed preoperatively, which is mainly due to the lack of distinctive symptoms or morphological features suggesting a malignant disease. As parathyroid carcinoma often has a genetic background, knowledge of mutation status and family history is of high relevance. Surgery with complete resection of the parathyroid carcinoma is the mainstay for a successful treatment and a good prognosis.