Chromosomal aberrations in two adrenocortical tumors, one with a rearrangement at 11p15

Genomic and expression profiling of adrenocortical carcinoma: application to diagnosis, prognosis and treatment

Adrenocortical carcinoma (ACC) is an aggressive endocrine tumor with a poor 5-year survival rate of 10–20%. Current therapy is often ineffective and may be associated with intolerable side effects. Although ACC is extremely rare, recent advances in genomic and expression profiling, coupled with knowledge gained from the study of the inherited syndromes that increase ACC risk, are beginning to bring together a picture of a tumor type dependent on p53, the G2/M cell cycle transition and IGF2 stimulation. Nevertheless, ACC remains a heterogeneous disease. Only recently have sufficient tumors been characterized and results published to permit an exploration of this diversity. Advances in treatment will depend on exploiting those pathways already implicated in ACC, along with those yet to be identified, and testing those treatments in better models of the disease than the three cell lines that currently exist and are widely available to the community.

Discerning malignancy in resected adrenocotical tumors

BACKGROUND

The number of adrenocortical tumors discovered incidentally has recently increased owing to the advent of imaging techniques. The most important diagnostic point in evaluation of resected specimens of these tumors is to discern malignancy to determine postoperative management of the patients.

OBJECTIVE/METHODS

To determine what the effective methods of discerning malignancy in resected specimens of adrenocortical tumors are at this juncture. To provide relevant and practical information pertinent to those involved in the management of patients with adrenocortical tumors.

CONCLUSION

Careful macroscopic evaluation, including the selection of the specimens submitted and application of the criteria of Weiss for histological diagnosis, is still considered the 'gold standard' for diagnosis of adrenocortical carcinoma. However, it is important to recognize its limitations in the diagnosis of adrenocortical oncocytoma and pediatric adrenocortical tumors. The auxiliary methods that may be of clinical relevance at this juncture include the analysis of the Ki67/MIB-1 labeling index and IGF-II expression in the tumors.

Analysis of numerical chromosomal aberrations in adrenal cortical neoplasms by fluorescence in situ hybridization

PURPOSE

We identified numerical chromosomal aberrations in adrenal cortical neoplasms using interphase fluorescence in situ hybridization (FISH) and correlated these aberrations with DNA ploidy and endocrine dysfunction.

MATERIALS AND METHODS

Our study included 25 adenomas and 2 carcinomas associated with primary aldosteronism or Cushing's syndrome. Eight normal adrenal tissue samples served as controls. Isolated nuclei from frozen samples were used for FISH and formalin fixed, paraffin embedded tissues from the same materials were analyzed by flow cytometry for DNA ploidy. For FISH we used centromere specific probes for chromosomes 3, 7, 8, 11 and 12.

RESULTS

None of the normal adrenal tissues had any numerical chromosomal aberrations in any chromosome analyzed or any abnormal findings on DNA ploidy analysis. Tetrasomy of chromosomes 3, 7, 8, 11 and 12 was detected in 8, 13, 14, 11 and 12 of the 17 adenomas associated with primary aldosteronism, and in 2, 0, 0, 0 and 0 of the 8 associated with Cushing's syndrome, respectively. DNA flow cytometry revealed tetraploidy in 11 of the 17 cases of primary aldosteronism and in 1 of the 8 of Cushing's syndrome. Five diploid adenomas associated with primary aldosteronism also showed tetrasomy in 2 or more chromosomes. One of the 2 carcinomas showed aneuploidy and aneusomy of chromosomes 8, 11 and 12 but the other showed no abnormal peaks on DNA histography and no numerical chromosomal aberrations.

CONCLUSIONS

All chromosomes analyzed in adenomas associated with primary aldosteronism frequently showed tetrasomy, whereas few chromosomal abnormalities were detected in adenomas associated with Cushing's syndrome. Our results indicate that DNA tetraploidy is common in adrenal cortical adenomas associated with primary aldosteronism. Interphase FISH strongly supported flow cytometry findings and could provide further information on individual chromosomes.

Complex karyotype in a childhood adrenocortical carcinoma

Cytogenetic analysis of short-term cultured cells from an 11-cm adrenocortical carcinoma in a 3.5-year-old girl revealed the karyotype 46,XX,inv(9)(p11q12)c/[2]/56-57,XX,+2,+4,+5,+7,+8,inv(9)c,+10,+add (13)(p11), +14,+15,+19,+20,+20,+mar[cp19]. To our knowledge, this is the first description of an abnormal karyotype in a pediatric adrenocortical tumor. Inasmuch as the distinction between benign and malignant adrenocortical tumors is often difficult to make from clinical and histopathologic data alone, the present findings suggest that cytogenetic analysis may be a valuable adjunct in the differential diagnosis.

Cytogenetic analysis of thyroid tumors after cryopreservation

Current cytogenetic evaluation of solid tumors is performed on fresh tissue specimens requiring on-call tissue culture facilities. The application of cryopreservation to tumor samples prior to cytogenetic analysis allows collection of tumors to a desired sample size. We evaluated methods of cryopreservation for their effects on growth potential from 11 benign thyroids and one papillary thyroid cancer. Mitotic indices and thyroglobulin expression applying imunocytology were analyzed. Compared to fresh tumors, the revived tumor samples showed unaltered thyroglobulin expression. A statistically significant (p < 0.004) prolongation to develop mitotic activity occurred in samples received after the freezing of dispase digested tissues, but not in samples frozen as thinly cut pieces. In addition, the data show that cytogenetic analysis at the 400-band level can be achieved in cryopreserved thyroid tissues.