Endocrine Abstracts

Introduction: Parathyroid carcinoma and atypical parathyroid adenoma are among rarely encountered causes of primary hyperparathyroidism. Patients with parathyroid carcinoma often differ from those with atypical parathyroid adenoma or parathyromatosis at the time of presentation because patients with parathyroid carcinoma have more profound hypercalcemia as well as invasive tumors. However, at times, it is difficult to distinguish between these conditions both clinically and by final histologic examination.We report the case of a 59 year old woman, who adressed the endocrinology department for assement of macropolinodular goiter with chronic Levothyroxin treatment, polyuria and lombar pain.

Clinical examination: High blood pressure, lombar pain, normal BMD, macronodular goiter, polyuria and polydipsia (about 5l per day).

Lab tests results: Normal CBC, normal fasting plasma gloucose, normal renal function, mild hypercalcemia (12 mg/dl), hyperphosphatemia, normal TSH, high PTH (172 pg/ml), supressed calcitonin; 24h urine sample revealed high urinary calcium, suggesting primary hyperparathyroidism.

Cervical region ultrasound: Macropolinodular goiter, posterior and caudal of the right thyroid lobe a hypoechoic mass lesion (17/9 mm) which seemed to communicate with a blood vessel, resembling a parathyroid adenoma. Lombar spine X-ray: cuneiform compression of L1, narrowing of the intervertebral T12-L1 space. DXA revealed osteoprosis with a increased mineral lost on the distal third radius. Scintigraphy scan of the cervical region was performed with no conclusive findings. The patient was refered to the surgery department for near-total thyroidectomy due to macronodular goiter and to examin and excise what seemed to be a parathyroid adenoma. The histologic examination of the tumor has established the atypical parathyroid adenoma diagnosis. The patient was refered back to us, after three weeks, for the postoperative assessment and she had normal calcemia.

Conclusions: Atypical parathyroid adenoma is a rare cause of primary hyperparathyroidism, no clincal or biological finding can distinguish between the etiological pathways of primary hyperparathyroidism, blood calcium levels do not seem to follow a specific pattern, although, in literature, is mentioned that a higher calcemia is most frequently related with parathyroid carcinoma or parathyroid atypical adenoma. Utlimately the histological exam is the one that clarifies the diagnosis and sets the subsequent therapeutic conduct, so the surgical excision of the suspected tumor is imperative, serving also as therapeutic diagnostic tool.