BackgroundThere is some evidence supporting the idea that double parathyroid adenomas represent a different entity from multiglandular hyperplasia; however, the distinction among them is not straightforward.Case presentationWe described a case of primary hyperparathyroidism (PHPT) with pronounced clinical manifestations, caused by a bilateral giant parathyroid adenoma. A 34-year-old Hispanic/Latino male was diagnosed with PHPT caused by two giant parathyroid adenomas. The preoperative tests were neck ultrasound and computed tomography scan (CT-scan), showing two masses in the territory of parathyroid glands, bilaterally distributed (right was 31 × 18 × 19 mm and the left was 38 × 15 × 14 mm); sestamibi scan was not available. Parathyroid hormone (PTH) was highly elevated. Multiple complications of PHPT were present, such as bone lytic lesions, renal and pancreatic calcifications, and cardiovascular disease, the latter of which is an overlooked complication of PHPT. Multiple endocrine neoplasia 1 and 2 (MEN 1/2) were ruled out by the absence of clinical, biochemical, and radiological findings in other endocrine glands. The patient underwent subtotal parathyroidectomy with an intraoperative histopathological study; both intraoperative and definitive histopathology results were consistent with parathyroid adenomas; afterward, adequate suppression of PTH was assured, and later on, the patient presented hungry bone syndrome (HBS).ConclusionsThe diagnosis of double parathyroid adenomas is difficult. Regarding the similarities between multiglandular hyperplasia and parathyroid adenomas, this case report contributes to the further distinction between these two clinical entities. This case report also represents, in particular, the challenge of difficult diagnosis in places with limited resources, such as developing countries.