Challenges in diagnosis and treatment of multiple atypical parathyroid tumors in a patient with extrapyramidal symptoms: case report and literature review

Background: Atypical parathyroid tumors (APTs) are rare entities. We report the case of a patient with multiple APT presenting with extrapyramidal symptoms and a delayed hypercalcemic crisis. Case Description: A 72-year-old man presented to a tertiary referral center's emergency room (ER) following two episodes of temporary loss of consciousness. He had a history of ideomotor sluggishness, lethargy, extrapyramidal symptoms and dysphagia, which started 6 months prior. Serum calcium levels at presentation were normal. Four days later the patient developed a rapidly evolving respiratory failure requiring orotracheal intubation, severe hypercalcemia (up to 19.8 mg/dL) and increased serum parathyroid hormone (PTH) (151 pmol/L). A neck ultrasound (US) showed two lesions posteroinferiorly to the right and left thyroid lobe. Since hypercalcemia proved to be refractory to medical therapy, the patient underwent urgent bilateral neck exploration with subtotal parathyroidectomy for suspect parathyroid carcinoma (PC). Histopathological examination showed three nodular lesions consistent with a diagnosis of APT in each excised parathyroid. Four months after surgery, the patient is alive and well with no signs of recurrence. Neurological follow-up visits documented the absence of extrapyramidal signs. Conclusions: Our patient showed an unusual presentation of primary hyperparathyroidism (PHPT) sustained by multiple concurrent APTs. A low suspicion threshold should be maintained to avoid delay in diagnosis. The present case adds to the body of literature on APTs, contributing to a greater understanding of this rare disease.