AIM : This study highlights the diagnostic and surgical challenges associated with such unusual presentations. METHODOLOGY: This is a retrospective study of a series of patients diagnosed with parathyroid adenoma presenting with atypical clinical, biochemical, or anatomical features at a tertiary care center. Clinical presentation, biochemical parameters, imaging findings, surgical management, and outcomes were analyzed. RESULTS: The series demonstrated a wide spectrum of unusual presentations. These included ectopic parathyroid adenomas located in uncommon sites such as the mediastinum and intrathyroidal region, cystic parathyroid lesions mimicking thyroid pathology, and cases presenting with non-classical manifestations such as recurrent pancreatitis and unexplained neuropsychiatric symptoms. In several patients, conventional neck ultrasonography and Tc-99m scintigraphy failed to localize the lesion, necessitating advanced imaging modalities including cross-sectional imaging and Choline PET CT for accurate localization. We operated 145 patients of hyperparathyroidism from February 2018 to March 2026. This include 134 cases of primary hyperparathyroidism. The cases with unusual presentation (total 29 cases) were ectopic location (8), pancreatitis (11), Brown tumors (3), MEN Syndrome (1), non localization on conventional imaging (6). All patients underwent surgical excision. Intra operative frozen section and PTH monitoring was done in all the cases. Post operative histopathology and biochemical evaluation was done in all cases and favourable outcome is achieved. CONCLUSION: Parathyroid adenomas can present with a broad spectrum of atypical clinical and anatomical features that may mimic other neck or systemic pathologies. A high index of suspicion, comprehensive biochemical evaluation, and appropriate localization imaging are crucial for accurate diagnosis. Recognition of these unusual presentations facilitates timely surgical intervention and optimal patient outcomes. Author declare no conflict of interest.