Introduction: Parathyroid lipoadenoma (PLA) is a rarely seen, benign variant of parathyroid adenoma (PA). However, PA usually consists of uniform, polygonal chief cells with a few nests of oxyphil cells, PLA consists of similar histologic features, but with an abundance of fat cells. Additionally, PLA may be functional with the secretion of parathyroid hormone (PTH) or non-functional. Here, we present a case of atypical PLA presented with severe hypercalcemia and skeletal deformities.
Case: A 41-year-old male referred to emergency department due to the cranial trauma following the syncope episode. In his cranial magnetic resonance imaging no pathology was found. He had no chronic disease except hypertension. His laboratory evaluation revealed elevated creatinine and calcium (Ca) levels (1.7 and 14.3 mg/dl, respectively). PTH level was found 735 pg/ml, urinary calcium excretion was found 348 mg/24 h. Neck ultrasound (US) revealed an isoechoic mass with 18.5×29.5×38.7 mm in size in the left inferior part of the thyroid gland which was consistent with parathyroid scintigraphy. Grade I hypertensive retinopathy was detected in ophtalmological examination. Bone mineral densitometry revealed severe osteoporosis, especially in lumbal vertebraes. Pathologic fracture was not determined in vertebral graphics. He had severe scoliosis and pectus excavatum. Ca levels were regressed to 12 mg/dl with intravenous hydration and diuretic treatment. He had underwent left hemithyroidectomy and parathyroidectomy and pathology was revealed atypical PLA and benign thyroid disease. Also the surgical specimen was revealed a large size mass with a 5 cm in diameter and neoplastic cells were seen in one area in the capsule.
Conclusion: Although PLAs are benign lesions, our case had atypical features. He had severe osteoporosis and skeletal anomalies in addition to severe hypercalcemia. However, there has been no known malignant PLA, the cases which show atypical features should be followed closely.