Background: Hyperparathyroidism is caused by parathyroid adenoma, hyperplasia or carcinoma. Parathyroid adenomas are the most common cause of parathyroid disease (85-88%) while atypical parathyroid adenomas and carcinomas are the least frequently seen parathyroid neoplasms which cause diagnostic difficulty. This series aims to identifiy lesions of parathyroidectomy specimens in our center and draw attention to borderline cases in between parathyroid adenoma and carcinoma.
Methods: The study included 638 parathyroidectomy materials diagnosed in our center between the years 2005 and 2016 and examined retrospectively, and all were included in the study.
Results: In all the 638 parathyroidectomy cases evaluated, 427 were diagnosed with adenoma, 117 with hyperplasia, 54 with normal parathyroid tissue, 32 with parathyroid neoplasm with uncertain malignant potential, 7 with parathyroid carcinoma and 1 with normal thyroid tissue.
Conclusions: Parathyroid neoplasm with uncertain malignant potential defines cases with suspicious histopathological features of carcinoma but doesn't meet the criteria for parathyroid carcinoma. In our series, these cases are identified as atypical parathyroid adenoma. We present clinical and morphological features of our parathyroidectomy cases in an 11-year period and aim to raise concern about borderline cases in between adenoma and carcinoma. We think that such tumors, similar to the thyroid neoplasm classification, should be defined as parathyroid neoplasms with uncertain malignant potential and should be followed closely.