Differences Between Atypical Parathyroid Tumors and Parathyroid Adenomas in Patients with Primary Hyperparathyroidism

Abstract

Atypical parathyroid tumor (APT) is a rare disease that can be challenging to distinguish from parathyroid adenoma. APT shows some laboratory and histopathological features with parathyroid cancer. This study attempts to compare clinical, laboratory, radiologic and histopathological characteristics in APT and parathyroid adenoma (PA). MethodsThis was a retrospective study was based on the database of eighty-two subjects who underwent surgery for primary hyperparathyroidism at a tertiary referral center between 2010 and 2021. Forty-one patients with APT matched by age and gender to controls with PA. Clinical, laboratory, radiologic and characteristics were obtained from the hospital database. ResultsForty-ve (54.8%) of primary hyperparathyroidism (PHPT) patients were symptomatic, 36 (90%) had nephrolithiasis, 6 (15%) had fracture and 3 (7.5%) had hypercalcaemic crisis. APT patients present with signi cantly inceased serum calcium, parathormone (PTH) and alkalen phosphatase levels (P < .001, all). No signi cant difference was observed in the results of bone mineral density (BMD), T-scores and Z-scores. The size of adenoma was signi cantly greater in APT group (24 (8.8-70) mm vs. 12 (3.8-32) mm, P = 0.005). During the follow-up, multiple metastases due to parathyroid cancer were detected in one patient. ConclusionOur study revealed that increased preoperative serum calcium, parathormone, alkalen phosphatase concentrations and parathyroid adenoma size on ultrasound may have predicted the atypical parathyroid tumor.Dual X-ray absorptiometry (DXA) (Hologic) was used to measure bone mineral density (BMD), T-score and Z-score of lumbar spine, femoral neck and total femur. Z-scores were used for participants younger than 50 years of age.Preoperative neck ultrasonography and dual-phase technetium-99m sestamibi were the preferred methods to localize parathyroid adenomas. None of our patients underwent diagnostic ne-needle aspiration biopsy before the operation.The histology excluded certain malignancy features like the presence of vascular, lymphatic, perineural invasion and/or local/distant metastasis. The histological criteria for identifying an atypical parathyroid tumor was included the trabecular growth pattern, atypical mitotic gures, brous band formations.The immunohistochemically staining was employed using GATA-3, chromogranin A and P53.This study was approved by the ethics committee of the Local Ethics Board (app. no.: 2021-19/13). Statistical AnalysisAccording to the normality tests, medical records of patients were expressed as mean and standard deviation (SD), median and range. Categorical variables were summarized with count and percentage. Pearson's chi-square was performed for comparisons of categorical variables. Continuous variables were compared using an independent samples t-test or Mann-Whitney test. The normality of data was explored by the Shapiro-Wilk test. Statistical analysis was performed using SPSS 23.0 software package. P-values less than 0.05 were considered statistically signi cant. ResultsEig...