Primary hyperparathyroidism characterized by diffuse homogeneous metastatic pulmonary calcification: A case report

RATIONALE: Primary hyperparathyroidism (PHPTI) with respiratory tract symptom is extremely rare. It is caused by autonomic oversecretion of parathyroid hormone (PTH) owing to parathyroid adenoma, hyperplasia, or tumor. The diagnosis of PHPTI often needs to be made based on medical history, clinical manifestation, laboratory tests, and imaging examination. Moreover, no study has reported PHPTI with diffuse metastatic pulmonary calcification (MPC) as the characteristic. PATIENT CONCERNS: A 49-year-old female from Zhejiang, China, had a fever of unknown origin, cough with white crude sputum, and asthma after activity for 1 month. DIAGNOSIS: The computed tomography (CT) examination revealed a homogeneous and diffuse high-density shadow in both lungs. The pathologic examination with CT-guided lung biopsy (left lung puncture) suggested interstitial inflammation of the lung tissue, combined with fibroblast proliferation as well as calcification. B-ultrasonography identified a lump in the right parathyroid gland, with a size of 4.1 × 1.7 × 1.9 cm(3). Color Doppler sonography indicated rich blood flow inside the lump. Whole-body bone emission computed tomography imaging showed the enhancement of bone metabolism in bilateral lower extremities and a diffuse enhancement of radioactive distribution in both lungs. (99m)Tc-methoxyisobutyl isonitrile imaging suggested significantly increased MIBI uptake in the right superior pole of the thyroid gland and indicated adenoma of the right superior parathyroid. The diagnosis of PHPTI was confirmed by postoperative pathology. INTERVENTIONS: The patient received a resection of the right parathyroid adenoma. OUTCOMES: After surgery, the symptom such as fever, coughing, and white crude sputum were significantly alleviated. LESSONS: This novel case reported the case of a patient with PHPTI having respiratory tract infection as the 1st symptom and diffuse MPC as the symptom characteristic PHPTI, the findings of this case study might improve the recognition of PHPTI on diffuse pulmonary calcification for clinical doctors.