Diagnostic relevance of chromosomal in‐situ hybridization in Merkel cell carcinoma: targeted interphase cytogenetic tumour analyses

Abstract

Had CISH been performed earlier, treatment may have been tailored specifically to suit MCC, since MCC and SCLC have different therapeutic strategies. Finally, chromosome X may be of prognostic relevance in MCC, which apparently predominates in females and yet shows poorer prognosis in males, and hence be worthy of further investigation.

Trisomy 6 in Merkel cell carcinoma: a recurrent chromosomal aberration

“…Tetrasomy can result from nuclear truncation of trisomic cells, providing further evidence that an actual gain of chromosome 6 did really occur in tumour cells. The case reported by Amo‐Takyi 27 showed the same phenomenon. Trisomy 6, however, did not seem to occur preferentially in metastatic tumours (6/11 primary tumours had trisomy 6), suggesting that the aggressiveness of the tumour might not be related to this genetic factor.…”

“…Working on paraffin‐embedded tissues, Amo‐Takyi et al . have reported that in 5–6 µm thick sections of normal tissue statistically 40 ± 5% of nuclei display one hybridization signal after ISH 27 . Up to 5% show three signals per nucleus, an artefact which may be due to truncation of some cell nuclei during tissue sectioning 28 .…”

“…Up to 5% show three signals per nucleus, an artefact which may be due to truncation of some cell nuclei during tissue sectioning 28 . A display of two hybridization signals of a diploid chromosome in at least 55% of the cell nuclei in normal tissue was considered as disomic; trisomy was diagnosed when at least 15% of cells displayed three hybridization signals 27 . Since portions of the nuclei were cut during preparation of the sections, nuclei with one or no signal were seen in all cases, obviously underestimating the chromosome copy number due to truncation of the nuclei.…”

UV‐B‐type mutations and chromosomal imbalances indicate common pathways for the development of Merkel and skin squamous cell carcinomas

“…However, less is known about genetic alterations. Despite a number of cytogenetic studies which questioned the prevalence of consistent aberrations, chromosomes 1 and 6 are believed to be most frequently involved in numerical or structural aberrations resulting in gains of chromosomal material 17, 18, 19. Comparative genomic hybridization (CGH) studies partly confirmed these findings but also demonstrated prevalence of loss of 3p, 10 and 17p as well as gain of 3q, 5p, 8q, 19 and X 19, 20.…”

Prognostic biomarkers, pathogenic studies and treatment of Merkel Cell Carcinoma

“…Newly postulated tumor suppressors gene (Ras association domain family 1 RASSF1A) belongs to the origin of neuroendocrine cells, 43,44 which also indicates histological parts of small blue cells and early metastasize tendency. Lots of other different chromosomal abnormalities are also defined in MCC including trisomy 1, trisomy 6, trisomy 11, trisomy 18 [45][46][47][48][49] and deletion of chromosome 7. 46 The loss of heterozygosity is also found in chromosome 10q (50) and chromosome 13.…”