Endocrine Abstracts

Introduction: Horner’s syndrome represents a clinical symptom that may result from a variety of lesions both in the central and peripheral nervous system. It is a combination of ipsilateral ptosis, pupillary miosis and anisocoria, enophthalmos and facial anhydrosis induced by disruption of the sympathetic innervation of the eye anywhere along its three-neuron trail. Tumors are the most frequent causes of Horner’s syndrome.

Aim: Aim of the study was to present a rare case of Horner’s syndrome caused by parathyroid adenoma.

Case report: 50-year-old man was initially diagnosed in neurology ward because of right Horner’s syndrome in the form of ptosis, pupillary miosis and enophthalmos. CT of the neck disclosed 30×26×16 mm homogenous solid tumor strictly adhering to the posterior contour of the right lobe of the thyroid with initial density 56 HU. Differential diagnosis included: atypical part of the thyroid gland, parathyroid adenoma or paraganglioma (in MRI). 99mTc-MIBI parathyroid scintigraphy revealed an area of increased tracer accumulation that could correspond to enlarged right parathyroid gland. PTH level was 347–426 pg/ml (n<72), total calcium level 11.8–12.9 mg/dl (n<10.4), ionized calcium 1.64–1.67 mmol/l (n<1.32). Low concentration of serum phosphorus (2.3 mg/dl) and increased urine calcium excretion (570–950 mg/24 h, n<300) were also observed. 25(OH)D3 blood level was 14.39 ng/ml (n>30). Due to the suspicion of PTH-secreting paraganglioma daily urine excretion of methoxycatecholamines (913 and 742 μg/24 h; n<1000) and biopsy of the lesion (parathyroid tissue) have been done. During surgery a tumor of the right upper parathyroid gland has been removed. The postoperative pathologic examination revealed 4.5×2.5×21.3 cm parathyroid adenoma. The Horner’s syndrome symptoms did not resolve after surgery.

Conclusion: Among the many causes of Horner’s syndrome, parathyroid tumor should be taken into account in the differential diagnosis.