Parathyroid carcinoma is a rare endocrine malignancy, accounting for less than 1% of cases of primary hyperparathyroidism. Patient-related factors such as age and sex, as well as the biological features and management of the cancer, influence mid-term and long-term survival. We report a case of a young man with an unusual presentation of parathyroid carcinoma. The patient presented with left thigh swelling, which had been present for 6 months without other symptoms of hypercalcemia. On computed tomography scan a hypodense lesion, 30 × 20 × 20 mm in size, was seen in the posterior thyroid. There was no evidence of cervical lymphadenopathy or local infiltration. On a Sestamibi scan, a hot spot was seen in the lower pole of left thyroid lobe. Cervical neck exploration was performed. The patient subsequently underwent surgery and a parathyroid tumor was excised. The tumor was adherent to the thyroid capsule, but there was no evidence of invasion. After surgery, the patient’s calcium and parathyroid hormone levels normalized, but histology confirmed parathyroid carcinoma with capsular and vascular invasion. The patient was offered reoperation, but declined, and developed recurrent parathyroid carcinoma 2 years later. In this report, we aim to present the challenges in managing parathyroid carcinoma and discuss factors that might contribute to future locoregional recurrences. This case also highlighted several issues, including the challenge of ascertaining the diagnosis before surgery and the dilemma of reoperation after simple excision.