Disseminated malignacy incidentally detected on scintigraphic parathyroid imaging in haemodialysed patient suffering from calciphylaxis
Abstract
A 74-year-old haemodialysed patient suffering from chronic renal failure and calciphylaxis, with kidney transplantation and graft rejection history, underwent parathyroid scan (dual-phase and subtracion protocol, using 99mTc-pertechnetate and 99mTc-metoxy-isobutyl-isonitrile, 99mTc-MIBI) due to elevated parathyroid hormone (PTH) levels. Parathyroid scan did not reveal parathyroid adenomas or hyperplasia; however a large cold nodule in the thyroid gland with 99mTc-MIBI uptake and two 99mTc-MIBI-avid pulmonary lesions (suggestive of metastasis) were detected.
Thyroid gland nodule fine-needle aspiration cytology was benign, with undetectable PTH and normal calcitonin levels. Contrast-enhanced neck and chest CT confirmed clearly visible pulmonary and hilar metastatic lesions and disclosed an abnormal lymph node near the coeliac trunk and a soft-tissue lesion in pancreatic head, highly suggestive of neuroendocrine tumour.
Surprisingly, their histology revealed renal cell carcinoma origin. Subsequent contrast-enhanced trunk CT detected a complex cyst (Bosniak III) in the left kidney upper pole, which could be the cystic kidney tumour.