Morphological evaluation of parathyroid adenomas and immunohistochemical analysis of pcna and ki-67 proliferation markers

Abstract

Objective: Parathyroid adenomas are the most common cause of primary hyperparathyroidism. Biological studies have shown that parathyroid adenomas are monoclonal proliferations. Up to date, five cell types have been identified in normal parathyroid tissues; chief cells, vacuolated chief cells, dark chief cells, oxyphil cells and transitional oxyphil cells. Most parathyroid adenomas are predominantly composed of chief cells.In this study, we aimed to indicate the relationship between the predominant cell type in parathyroid adenomas and proliferating cell nuclear antigen, Ki-67 antigen, and serum parathormone levels and the gland weight. Material and Method:15 cases who had a diagnosis of parathyroid adenomas were included in the study. Histopathologically, the predominant cell type was determined in all the cases. Paraffin blocks were immunohistochemically stained with proliferating cell nuclear antigen and Ki-67. Results:The average parathormone level of the cases was 239.52 ± 36.61 pg/ml before surgery. Mean gland weight was 1.69 ± 0.49 g. Two of the cases showed atypical adenoma characteristics. The predominant cell type was vacuolated chief cell. Immunohistochemical investigation showed that the mean average Ki-67 index value was 4.26 ± 0.86%. The mean proliferating cell nuclear antigen index was 93.20± 45.72/10³. There was a meaningful relationship between gland weights and serum parathormone levels. There was no meaningful relationship between predominant cell types and serum parathormone levels, proliferating cell nuclear antigen index, and Ki-67 index. The chief cell was identified as the predominant cell type. Conclusion Bulgular:Hastaların tümü kadın olup ortalama yaş 58 ± 13,36 olarak saptandı. Operasyon öncesi ortalama parathormon düzeyleri 239,52 ± 36,61 pg/ml idi. Bez ağırlıkları ortalama 1,69 ± 0,49 gr idi. Olgulardan biri lipoadenomdu. İki tanesi atipik adenom özellikleri göstermekteydi. Olgulardan 8 tanesinde baskın hücre tipi "berrak esas hücre", 6 tanesinde "esas hücre", 1 tanesinde ise "oksifil hücre" idi. İmmünohistokimyasal incelemelerde Ki-67 indeksi ortalama değeri % 4,26 ± 0,86 olarak saptandı. Prolifere hücre nükleer antijeni indeksi ortalama 93,20 ± 45,72/10³ olarak belirlendi. Bez ağırlıklarının serum parathormon düzeyleri üzerine anlamlı etkisi olduğu saptandı. Baskın olan hücre tiplerinin serum parathormon düzeyleri, Prolifere hücre nükleer antijeni indeksi, Ki-67 indeksi üzerine anlamlı etkisi olmadığı tespit edildi. Sonuç olarak çalışmamızda olguların çoğunda baskın hücre tipi esas hücre olarak saptanmıştır.

Parathyroid adenoma: a comprehensive biochemical and histological correlative study

“…We found only one statistically significant correlation, between chief‐cell percentage and PTA weight ( P = 0.044). Most of the PTAs had a predominance of chief cells, consistent with earlier findings that chief‐cell PTAs are the most common type of PTA in PHPT . As chief cells secrete PTH, the higher proportion of this cell type would have been expected to lead to higher PTH levels and, consequently, higher blood calcium levels.…”

“…Most of the PTAs had a predominance of chief cells, consistent with earlier findings that chief-cell PTAs are the most common type of PTA in PHPT. 9,10,19 As chief cells secrete PTH, the higher proportion of this cell type would have been expected to lead to higher PTH levels and, consequently, higher blood calcium levels. However, no correlation was found between the proportion of chief cells and PTH or calcium levels.…”

“…Their function remains unknown. PTAs with more than 70% chief cells are by far the most common documented cause of PHPT . Oncocytic (oxyphil)‐cell adenomas and clear‐cell adenomas (composed of cells with clear‐to‐foamy cytoplasm) occur less frequently; lipoadenomas, an unusual morphologic variant, are rare …”

Rak przytarczycy jako przedoperacyjny dylemat diagnostyczny – opis przypadku i przegląd piśmiennictwa

“…Immunohistochemistry using anti-PTH antibodies has not been demonstrated to be useful in the diagnosis of PC [26]. Nevertheless, a proliferation index evaluated by the Ki-67 antibody higher than 5% is associated with a higher suspicion of malignancy and the risk of recurrence [27]. In the presented case, the mitotic index and proliferation index were three figures per ten high-power fields and 1%, respectively.…”

Molecular profiling in primary hyperparathyroidism

“…Studies revealed that the percentage of positively stained for Ki‐67 tumor cells is often associated with the clinical course of the disease . Parathyroid carcinomas showed higher Ki‐67 expression compared with adenomas and hyperplasias, however, there is an overlap between benign and malignant parathyroid lesions . World Health Organization guidelines suggest that patients with tumors with Ki‐67 counts greater than 2% to 3% should have a closer follow‐up because of an increased risk of malignancy…”