Evaluation of clinicopathological differences according to age groups in patients operated for hyperparathyroidism

This study aimed to comprehensively evaluate the influence of age and sex on the clinical, biochemical, imaging, pathological, and postoperative outcomes of patients who underwent surgery for primary hyperparathyroidism. A total of 427 patients operated between 2015 and 2023 were retrospectively analysed and stratified into three age groups (≤44 years, 45–59 years, ≥60 years). Sex-related differences were also examined in detail. The primary objective was to determine whether the clinical spectrum of primary hyperparathyroidism varies with age, whether preoperative imaging accuracy is affected by demographic factors, and whether postoperative biochemical recovery differs among age or sex groups. Demographic assessments showed a female predominance in the study population. Presenting symptoms were largely similar across age groups, with a relatively higher proportion of asymptomatic cases in younger patients. Classical manifestations such as urinary complaints, bone pain, and fatigue occurred at comparable rates across all age categories. Symptom profiles also showed no significant sex-related differences, suggesting that the clinical presentation of primary hyperparathyroidism remains stable regardless of demographic factors. Preoperative laboratory analyses revealed no significant differences in PTH, phosphorus, calcium, urinary calcium, vitamin D, or alkaline phosphatase levels among age groups, except for slightly higher serum calcium in younger patients, possibly indicating earlier diagnosis or greater glandular activity. Laboratory parameters were also similar between male and female patients, indicating that disease burden did not differ by sex. One of the most notable findings of the study was the performance of preoperative imaging modalities. Overall, ultrasonography and scintigraphy demonstrated comparable sensitivities; however, scintigraphy exhibited superior specificity and accuracy. Importantly, imaging success varied across demographic subgroups. The highest diagnostic accuracy for both ultrasonography and scintigraphy was observed in the middle-aged group (45–59 years), indicating that imaging results are more reliable and predictable in this population. Additionally, both sensitivity and accuracy of imaging modalities were significantly higher in female patients than in males, suggesting that anatomical or physiological differences-such as adipose tissue distribution, neck contour, or gland characteristics-may contribute to improved visualization in women. Another key finding was the strong association between gland size and imaging performance: accuracy increased progressively with gland size, with scintigraphy achieving optimal performance in adenomas larger than 3 cm. Pathological evaluation showed that single-gland adenoma was the predominant histopathological diagnosis across all age and sex groups, while hyperplasia occurred less frequently. This distribution aligns with existing literature and reinforces adenoma as the most common cause of primary hyperparathyroidism. Although gland size did not differ significantly across age groups, larger glands (>3 cm) were more frequently observed in male patients. Nevertheless, gland size was not associated with malignancy or hyperplasia, indicating that size does not reflect disease aggressiveness but remains an important determinant of imaging accuracy. Surgical success was consistently high across all demographic subgroups. Intraoperative PTH decline did not differ significantly among age groups, and postoperative PTH and calcium levels normalized similarly at 1, 3, 6, and 12 months, demonstrating uniformly effective biochemical recovery irrespective of age or sex. Requirements for intravenous calcium or vitamin D replacement were also comparable across demographic categories. Postoperative complication rates were low in all age groups, with transient hypocalcaemia and hematoma being the most common events, consistent with reported rates in the literature. Permanent hypocalcaemia, recurrent laryngeal nerve injury, persistent voice changes, and recurrence were rare and showed no significant association with age or sex. Reoperation rates were also similar across groups, reaffirming the safety of parathyroid surgery in experienced centers. In summary, this study demonstrates that age and sex do not significantly influence the clinical presentation, biochemical severity, pathological distribution, or postoperative recovery in primary hyperparathyroidism. However, the markedly higher imaging accuracy observed in middle-aged patients and in women provides clinically relevant information for preoperative planning. The consistently high surgical success rates in all demographic subgroups further indicate that age should not be considered a limiting factor when evaluating surgical candidacy. With its large sample size and comprehensive analytic approach, this study contributes valuable insights into the role of demographic variables in the management of primary hyperparathyroidism and supports evidence-based decision-making in clinical practice. Keywords: Primary Hyperparathyroidism, Parathyroidectomy, Imaging Accuracy, Parathyroid Adenoma, Parathyroid Hyperplasia, Surgical Outcomes