Parathyroid carcinoma: The relationship of nuclear DNA content to clinical outcome

This article reports the use of flow cytometry to determine tumor nuclear DNA content and its correlations with clinical outcome in a series of patients with parathyroid carcinoma. Information concerning nine patients with parathyroid cancer (aged 25 to 88 years) was reviewed. Paraffin-embedded, formalin-fixed archival tissue was used to determine tumor DNA content flow cytometrically. Twenty-five operative procedures were performed in nine patients, including 11 parathyroidectomies, two wide local excisions, six central neck dissections, and four median sternotomies for resection of metastases. With flow cytometry used to determine a tumor DNA index, five patients had evidence of tumor aneuploidy; in two patients two aneuploid peaks were evident. The DNA index ranged from 0.7 (hypodiploid) to 1.92 (mean, 1.31). Follow-up ranged from 1 to 18 years. Four patients died. Five were alive 1 to 13 years after diagnosis of parathyroid disease. Four of the five patients with evidence of tumor aneuploidy had metastatic disease and died, and the fifth has had three local recurrences. The four patients with diploid tumors were alive and free of disease 1, 3, 4, and 8 years after the initial operation. It is concluded that in patients with clinically or pathologically demonstrated parathyroid cancer, flow cytometry may help differentiate those whose cancers are likely to behave indolently (diploid tumors) from those with tumors (aneuploid) more likely to behave aggressively by recurring locally or metastasizing.