Sigmoid colon cancer associated with primary hyperparathyroidism: Report of a case

We present herein a case of sigmoid colon cancer associated with primary hy perparathyroidism (PHP). PHP is known to be associated with malignancy, and decreased intracolonic calcium (Ca) resulting from increased vitamin D (VD ) levels may play a role in colorectal carcinogenesis. PHP was diagnosed in this patient by preoperative screening blood chemistry examination. The bl ood level of intact parathyroid hormone (PTH) was elevated and a parathyroi d gland scintigram demonstrated abnormal uptake near the right lower lobe o f the thyroid. There was no evidence of bone metastasis, and a sigmoid cole ctomy was performed with curative intent. The patient had an uneventful pos toperative course without a critical elevation of the serum Ca level. This case report suggests that a relationship exists between PHP and colon cance r, and the possible mechanisms of this association are presented in our dis cussion.