Serum Immunoreactive Calcitonin in Lung Cancer

Apparently Nonfunctioning Metastases of Parathyroid Carcinoma

A 41-year-old woman was operated on for severe hyperparathyroid syndrome. At surgery a parathyroid tumor with the histopathologic pattern of carcinoma was found. After surgery serum calcium settled within normal limits (10.5 mg/dl, N.V. 8.5–10.8), whereas parathormone and calcitonin reached progressively high levels, respectively 400 ng/dl (N.V. up to 250) and 500 pg/ml (N.V. up to 100 ng/ml). Serum ultrafiltration analysis for parathormone and calcitonin showed many peaks of immunoreactivity with high molecular weight of both hormones. One year after surgery, metastases developed in the lymph nodes of the neck and the mediastinal, pleural and pancreatic regions. After death for tumor wasting, immunohistochemical study of the tumoral tissue with the peroxidase-antiperoxidase technique showed a relatively high density of calcitonin-containing cells. The findings in this case suggest that: a) several cells in this parathyroid cancer could secrete both parathormone and calcitonin; b) the hormonal secretion was impaired as suggested by the high molecular weight of both hormones found at gel-filtration analysis; c) the macromolecular profile of parathormone could explain the apparent function of the parathyroid cancer.