Endocrine Abstracts

Introduction: Parathyroid carcinoma represents a rare malignant etiology of primary hyperparathyroidism, with an incidence of 0.36 per 10 million individuals annually, accounting for 0.4% to 5% of all hyper parathyroid cases. Clinical suspicion arises in patients presenting with severe hypercalcemia, markedly elevated parathyroid hormone levels, palpable neck masses, and evidence of end-organ damage affecting bone and renal systems. Preoperative diagnosis remains challenging, necessitating multimodal imaging and histopathological confirmation. Long-term surveillance through serial biochemical monitoring and imaging is essential given the propensity for local recurrence and distant metastases.

Case Presentation: We report a case of a 24-year-old woman with ulcerative colitis who presented with neuropsychiatric symptoms including depression, irritability, and dysphagia. Laboratory investigations revealed severe hypercalcemia (adjusted calcium 3.24 mmol/l), elevated parathyroid hormone (42.2 pmol/l), hypophosphatemia, and hypercalciuria (16.91 mmol/day). Bone densitometry demonstrated osteopenia (lumbar spine Z-score -1.5, left hip Z-score -1.7, femoral neck T-score -1.6). Four-dimensional computed tomography identified a 16×15×54 mm hyper vascular lesion inferior to the right thyroid lobe with arterial enhancement and prominent vascular supply from the right inferior thyroid artery, consistent with parathyroid adenoma. Right inferior parathyroidectomy was performed successfully. Histopathological examination revealed a hypercellular parathyroid lesion composed predominantly of chief cells with mild to moderate nuclear atypia, low mitotic activity (1-2/10 high-power fields), and positive margins. Immunohistochemistry demonstrated retained parafibromin expression and Ki-67 proliferation index of 4-5%. While features Features were fall short of parathyroid carcinoma but atypical parathyroid is a consideration. Postoperative biochemical parameters normalized and whole body imaging negative for metastatic lesions.

Conclusion: This case highlights the diagnostic complexity of atypical parathyroid lesions that exhibit concerning histological features without meeting definitive criteria for malignancy. Such cases require prolonged surveillance protocols to monitor for potential recurrence and ensure optimal patient outcomes.