Flow cytometric dna analysis of parathyroid tumors with special reference to its diagnostic and prognostic value in parathyroid carcinoma

Abstract

The nuclear DNA content of paraffin-embedded parathyroid tumors from 49 patients with proven primary hyperparathyroidism was determined by flow cytometric analysis. The lesions included 14 primary and 11 locally recurrent or metastatic lesions from 16 carcinoma patients, 28 single adenomas from 28 patients, and 15 hyperplastic glands from five patients with familial multiple endocrine neoplasia type 1. No abnormal DNA stemline was found in any of the hyperplastic glands. One (3.6%) of the adenomas was aneuploid. There was no difference in ploidy patterns between the primary and recurrent lesions of the carcinomas and five (31%) of the carcinomas expressed aneuploidy. Four of the five patients with aneuploid carcinoma had recurrences including pulmonary metastases. One of them died of this disease 12 years after the initial operation, and all except one of the others are hypercalcemic even after removal of the successive recurrent or metastatic tumors. Of the 11 patients with diploid carcinoma, four had either local recurrence or pulmonary metastasis. Two of them are living with normocalcemia 3 and 6 years, respectively, after removal of the recurrent tumors and the others are alive with mild hypercalcemia. The remaining seven patients with diploid carcinoma, however, have no recurrence 2 to 5 years after the initial operation. Thus aneuploid parathyroid carcinomas are likely to show more malignant behavior than those with a diploid DNA pattern. All of the patients with adenoma and hyperplasia have been normocalcemic after a mean follow-up interval of 37 months. This study indicates that flow cytometric analysis of nuclear DNA content is a valuable adjunct to histologic examination in the diagnosis of parathyroid carcinoma and the prediction of the clinical outcome.

Relationship of AgNOR counts and nuclear DNA content to survival in patients with parathyroid carcinoma

“…Unfortunately, the aneuploid DNA pattern occurs in too large a fraction of benign parathyroid lesions to be useful for differentiating between PA and PC (Mallette 1992, Obara et al 1997. However, the DNA ploidy pattern may be a valuable prognostic factor to predict recurrence (Obara et al 1990(Obara et al , 1997. We found aneuploid tumours in 11 of 15 patients with PC, and in three of 15 patients with PA.…”

“…It is difficult to determine the prognosis for patients with PC solely from the results of tumour DNA cytometry, and some studies considered the DI to be of no value in deciding the benign or malignant character of a parathyroid tumour (Obara et al 1990, Kameyama et al 1999. Thus, parameters other than DI were investigated, such as proliferating cell nuclear antigen (PCNA), the cell cycle-associated antigen Ki-67 and AgNOR counts.…”

“…As suggested by Obara et al (1990), disaggregation was obtained by using 0.5% pepsin solution at pH 1.5. The sample was filtered (40 mm nylon mesh), and the single-cell nucleus suspension was resuspended in a solution containing propidium iodine and ribonuclease A.…”

“…The sample was filtered (40 mm nylon mesh), and the single-cell nucleus suspension was resuspended in a solution containing propidium iodine and ribonuclease A. Flow cytometer measurement was used, and 20 000 nuclei were read for each sample (Obara et al 1990, Bosci et al 1998. The DNA content was interpreted as diploid if only one G0/ G1 peak was present (DI¼1.0), and the DI was calculated as the ratio of the peak channel number of the aneuploid G0/G1 peak to the peak channel number of the diploid G0/G1 peak (August et al 1993).…”

Parathyroid carcinoma: A 22‐year experience

“…Previous reports have identified aneuploidy and nuclear DNA content as a discriminating factor indicating more aggressive tumors. 18,29 Availability of specific immunohistochemical staining, such as inactivating mutations in tumor suppressor genes, may in the future help to better define parathyroid carcinoma. 10,18,30 Oftentimes, the malignant potential of parathyroid tumors is not appreciated even postoperatively, until the histopathologic examination is complete or later when a relapse occurs.…”