Clonal patterns in phaeochromocytomas and MEN-2A adrenal medullary hyperplasias: histological and kinetic correlates

Abstract

The relationship among histological features, cell kinetics, and clonality has not been studied in adrenal medullary hyperplasias (AMHs) and phaeochromocytomas (PCCs). Thirty-four PCCs (23 sporadic and 11 MEN-2A (multiple endocrine neoplasia type 2A)-related tumours, the latter associated with AMH) from females were included in this study. Representative samples were histologically evaluated and microdissected to extract DNA and evaluate the methylation pattern of the androgen receptor alleles. At least two tissue samples (from the peripheral and internal zones in each tumour) were analysed with appropriate tissue controls run in every case. The same areas were selected for MIB-1 staining and in situ end labelling (ISEL). Malignant PCCs were defined by histologically confirmed distant metastases. All monoclonal AMH nodules from the same patient showed the same X-chromosome inactivated. Six sporadic PCCs revealed liver metastases (malignant PCC) and eight additional sporadic PCCs showed periadrenal infiltration (locally invasive PCC). All informative PCCs were monoclonal, except for five locally invasive PCCs and one benign PCC that revealed polyclonal patterns. Those cases also showed a fibroblastic stromal reaction with prominent blood vessels, focal smooth muscle differentiation, and significantly higher MIB-1 (126.8+/-29.9) and ISEL (50.9+/-12.8) indices. Concordant X-chromosome inactivation in nodules from a given patient suggests that MEN-2A AMH is a multifocal monoclonal condition. A subgroup of PCCs characterized by balanced methylation of androgen receptor alleles, high cellular turnover, and stromal proliferation also shows locally invasive features.

Heterogeneous topographic profiles of kinetic and cell cycle regulator microsatellites in atypical (dysplastic) melanocytic nevi

“…However, precancerous lesions and early neoplasms (even those with low nuclear grade) can show the genetic and kinetic Kinetic and microsatellites in AMN features of established malignancies (clonal proliferation with accumulation of cooperative genetic abnormalities, and advantageous proliferation/ apoptosis disbalance), along with molecular evidence of progression. 1,6,17,27,28,44,45 This progression would be related to the accumulation of genetic abnormalities and selective segregation of tumor cells with invasive capabilities, which are frequently topographically distributed. 20,23,46 A progressive and significant reduction in marker expression from junctional to deep dermal compartments was a general finding mirrored by the microsatellite profile.…”

“…7,18,20,24,27,28 This ratio represents 80% of clonal cells in the sample and hence was used to increase the detection specificity. 7 (b) Additional allele bands present in tumor samples but not in the corresponding controls were considered as evidence of somatic microsatellite abnormalities.…”

Intra-tumoral molecular heterogeneity in benign and malignant pheochromocytomas and extra-adrenal sympathetic paragangliomas

“…Therefore, we determined the intratumoral molecular heterogeneity in a series of 12 benign tumors (11 PCC and 1 sPGL) and 8 malignant tumors (seven PCC and one sPGL) by LOH analysis in different areas of the tumors. Molecular intra-tumoral heterogeneity within tumors has been reported in 55% of meningiomas (Sayagues et al 2004), 45% of renal tumors (Nenning et al 1997), 2.7% of cervical cancer (Bachtiary et al 2006), and in 8.8% of PCC (Diaz-Cano et al 2000). It is important to emphasize that these frequencies show extreme variation because 1) the amount of markers or probes used per study are different.…”

“…Jarbo et al (2005) reported that the ratios of chromosome 22q loss in some PCC samples were higher than expected for a single allele ratio, and suggested this could be due to intra-tumoral heterogeneity. Diaz-Cano et al (2000) investigated heterogeneity of sporadic and MEN 2-related PCC and adrenal medullary hyperplasia (AMH) nodules, by determining the methylation patterns of the androgen receptor (AR) gene, localized on the X-chromosome. All informative AMH showed concordant inactivation of the same alleles in different nodules from the same adrenal gland, suggesting that these AMH nodules arose from a common progenitor and are clonally related proliferations.…”

Coexistent intraurothelial carcinoma and muscle-invasive urothelial carcinoma of the bladder: clonality and somatic down-regulation of DNA mismatch repair

“…The sections were mounted on positively charged slides (Superfrost Plus, Fisher Scientific, Fair Lawn, NJ), baked at 60°C for 2 hours, and processed as described [16,17,25]. After routine dewaxing and rehydration, endogenous peroxidase quenching, and antigen heat retrieval (pressure cooker, citrate buffer [10 mmol/L], for all antibodies), the slides were transferred to a moist chamber.…”