Analysis of chromosomes 8 and 17 aneuploidies in laryngeal squamous cell carcinoma by fluorescence in situ hybridization

Graft-versus-host disease: role of inflammation in the development of chromosomal abnormalities of keratinocytes

Graft-versus-host disease (GVHD) is a major risk factor for secondary malignancy after hematopoietic stem cell transplantation. Squamous cell carcinoma (SCC) of the skin and mucous membranes are especially frequent in this setting where aneuploidy and tetraploidy are associated with aggressive disease. The current study is directed at the mechanism of neoplasia in this setting. Unmanipulated keratinocytes from areas of oral GVHD in 9 patients showed tetraploidy in 10% to 46% of cells when examined by florescein in situ hybridization (FISH). Keratinocytes isolated from biopsy sites of GVHD but not from normal tissue showed even greater numbers of tetraploid cells (mean = 78%, range: 15%-85%; N = 9) after culture. To mimic the inflammatory process in GVHD, allogeneic HLA-mismatched lymphocytes were mixed with normal keratinocytes. After 2 weeks, substantial numbers of aneuploid and tetraploid cells were evident in cultures with lymphocytes and with purified CD8 but not CD4 cells. Telomere length was substantially decreased in the lymphocyte-treated sample. No mutations were present in the p53 gene, although haploinsufficiency for p53 due to the loss of chromosome 17 was common in cells exposed to lymphocytes. These findings suggest that in GVHD, inflammation and repeated cell division correlate with the development of karyotypic abnormalities.

Evaluation of c-MYC status in primary acquired cholesteatoma by using fluorescence in situ hybridization technique

OBJECTIVE

The object of study was to investigate the status of c-MYC oncogene in primary acquired cholesteatoma.

STUDY DESIGN

Descriptive study.

METHODS

Cholesteatoma samples were obtained from 15 patients with primary acquired cholesteatoma during surgical operation. Fluorescence in situ hybridization with a mixed DNA probe, which is specific for c-MYC located on 8q24 and chromosome 8 specific-alpha-satellite DNA probe (dual color), was used on the interphase nuclei.

RESULTS

Copy number of c-MYC oncogene and aneuploidy of chromosome 8 were 21.2% +/- 14.4% and 21.7% +/- 14.8%, respectively. There was no significant difference between copy number of c-MYC and frequency of chromosome 8 aneuploidy (p > 0.05). Ten of 15 cases showed different percentage of c-MYC and chromosome 8 aneuploidy, whereas 5 (33.3%) of 15 cases showed a normal distribution of c-MYC and chromosome 8 signals.

CONCLUSION

The copy number of c-MYC in 10 of 15 cases was found to be high as observed for chromosome 8 aneuploidy in primary acquired cholesteatoma. These findings suggest that the ability of hyperproliferation of primary acquired cholesteatoma might have been related to c-MYC copy number by deregulating c-MYC expression.

Basaloid squamous carcinoma of the larynx. A potential diagnostic pitfall

Basaloid squamous carcinoma is a rare variant of squamous cell carcinoma. It is frequently diagnosed at an advanced stage with metastases. Histologically, it is identical to basaloid carcinoma at other anatomical sites. Some authors suggest that it may be associated with second primary tumors. Others implicate the Epstein-Barr and human papilloma viruses. All reports but one warn of its aggressive biological behavior. Our case concerns a 52-year-old man who had a small lesion in his right cord. Biopsy of the lesion was performed twice, and conventional squamous cell carcinoma was diagnosed; the patient returned 2 months later with progressed metastatic disease. The patient underwent a laryngectomy and a complete clinical and immunohistochemical investigation. Basaloid squamous carcinoma is a totipotential neoplasm with a grave prognosis. It can be misdiagnosed; therefore, the authors would like to emphasize the significance of this condition in comparison to conventional squamous cell carcinoma, and we provide a review of the relevant recent literature.