Cytogenetic findings in a human malignant melanoma metastatic to the brain

MOLECULAR PROGNOSTICS FOR UVEAL MELANOMA

PURPOSE

To review laboratory methods, currently available commercial tests, caveats and clinical tips regarding prognostic analysis of uveal melanoma tissue.

METHODS

A review of the literature was performed focused on the genetic abnormalities found in uveal melanoma cells, their correlation to the development of metastases, the validity of various laboratory approaches in their detection, and the existing commercially available tests for uveal melanoma prognostication.

RESULTS

Numerous laboratory methods exist for analyzing genetic material obtained from uveal melanoma cells. Older tests have been gradually replaced with contemporary methods that are simpler with greater accuracy. Two commercially available assays exist which have not been directly compared-a gene expression profiling test has been validated directly through a large, prospective multicenter study and a DNA-based test which uses laboratory methods supported by extensive historical data.

CONCLUSION

There are myriad laboratory methods for prognostic analysis of uveal melanoma tissue. These tests were historically only available to those with access to an outfitted laboratory. Newer commercially available assays have increased the accessibility of prognostic biopsy for uveal melanoma. The various caveats that exist when considering and performing prognostic biopsy of uveal melanoma are discussed.

Chromosomal 3 and 8 status within hepatic metastasis of uveal melanoma

CONTEXT

Several studies have evaluated clinical, histopathologic, cytogenetic, and molecular prognostic variables in uveal melanoma. However, it is not known whether the primary tumor cells maintain these aggressive attributes at the metastatic sites.

OBJECTIVE

To determine the status of chromosomes 3 and 8q and c-myc amplification using fluorescence in situ hybridization on hepatic metastatic lesions of primary uveal melanoma.

DESIGN

Ten patients with uveal melanoma with needle core biopsy-confirmed hepatic metastasis. Representative paraffin blocks were selected based on review of hematoxylin-eosin-stained sections. Fluorescence in situ hybridization was performed for detection of monosomy 3 and amplification at the 8q24 MYC locus using standard methods. The tricolor chromosome enumeration probe 8 (CEP8)/IGH/MYC and the Urovysion probe consisting of CEP3, CEP7, CEP17, and 9P21 probes were used. A total of 200 interphase cells were scored.

RESULTS

Hepatic metastasis was confirmed in each case by needle core biopsy. Fluorescence in situ hybridization analysis revealed chromosome 3 monosomy in 5 of the 8 cases that could be satisfactorily evaluated. Aneusomy of chromosome 8 was observed in 2 cases. MYC amplification was observed in 5 samples. In a single case where the primary tumor was treated by enucleation, the chromosomal monosomy 3 and aneusomy of chromosome 8 were present both in the primary tumor and its hepatic metastatic lesion.

CONCLUSIONS

The presence of cytogenetic changes within the metastatic lesions confirms that chromosome 3 monosomy and aneusomy of chromosome 8 are not just markers of metastatic potential of the primary tumor but are also present within the hepatic metastatic lesions.

[Cerebrospinal fluid in the diagnosis of cerebro-meningeal metastasis from malignant melanoma arising from giant congenital melanocytic nevus: case report]

We describe the case of a 28-year-old man with a giant congenital melanocytic nevus (GCMN) with malignant transformation to melanoma and metastasis on the central nervous system (CNS). We also make a summary of the pathological features from both lesions (GCMN and Melanoma), the occurrence of malignancy of GCMN, the organs more frequently involved with metastatic melanoma--with emphasis to involvement of CNS--just as the factors that cause malignant transformation of GCMN; the methods to diagnose metastases in CNS--emphasizing the importance of cerebrospinal fluid--and some therapeutical modalities for the metastatic melanoma in CNS.

Cytogenetic findings in 21 malignant melanomas

Cytogenetic analysis was performed on 21 tumor samples of malignant melanoma to identify the presence of consistent chromosome abnormalities. Four cases had a normal karyotype, and 17 were cytogenetically abnormal. Numerical chromosome alterations were observed in 15 tumors: 12 were hyperdiploid and three were hypodiploid. The most frequent losses consisted of chromosomes 5, 9, 17 and Y. The structural abnormalities were usually complex, consisting mainly of nonreciprocal translocations and deletions affecting 1p, 1q, 3p, and 9p. This study adds further data to previously reported melanoma cases, confirming that chromosomes 1, 3, 6, and 9 are nonrandomly affected.

Cytogenetic findings in primary uveal melanoma

We analyzed cytogenetic abnormalities in 10 cases of primary uveal melanoma. Clonal chromosomal abnormalities were present in nine cases. Chromosome 6 was most commonly affected (seven cases) and included gain of material from 6 and/or loss of material from 6q. Trisomy of chromosome 8 or gain in material from 8q, mostly in the form of an i(8q) resulting in three to five copies of the 8q segment was seen in six cases. Monosomy of chromosome 3 and rearrangements of chromosome 9 were less frequent and were altered in three cases each. Clinical, histopathologic, and cytogenetic abnormalities are correlated.

Cytogenetic analysis of uveal melanoma. Consistent occurrence of monosomy 3 and trisomy 8q

BACKGROUND

The genetic alterations associated with the pathogenesis of uveal melanoma have not been determined. To address this issue, the authors performed a prospective cytogenetic study of 35 uveal melanomas, including 23 primary untreated tumors and 12 tumors that were removed after local radiation therapy.

METHODS

Representative tumor tissue was processed by established methods for histopathologic and cytogenetic studies. Tumor cells were disaggregated and established in short-term culture; metaphases were prepared by standard methods for karyotypic analysis.

RESULTS

Successful analyses were achieved in 27 of the tumor specimens, including 20 of 23 tumors not exposed to radiation and 7 of 12 tumors exposed to radiation. All of the tumors had an abnormal karyotype. Recurrent chromosomal abnormalities detected in the tumors not exposed to radiation included monosomy 3 (13 of 20), trisomy 8 or 8q (11 of 20), loss of a sex chromosome (10 of 20), and loss of 6q (8 of 20). The tumors previously exposed to radiation were characterized by more complex changes, with monosomy 3 and trisomy 8q detected in three cases each.

CONCLUSIONS

Uveal melanoma is characterized by monosomy 3 and trisomy 8q in most cases. These findings, which are supported by data from other investigators, provide compelling evidence that loss of gene sequences on chromosome 3 and duplication of gene sequences on chromosome 8 are implicated in the genetic alterations associated with uveal melanoma and offer a basis for additional molecular genetic investigations.

Preferential chromosome 11q and/or 17q aberrations in short-term cultures of metastatic melanoma in resections from human brain

Thirteen specimens of metastatic malignant melanoma resected from eight patients undergoing craniotomy were analyzed cytogenetically from short-term cultures. All patients had chromosome 1 aberrations, as did three of four patients with metastases only to extracranial sites. Both groups had variable involvement of chromosomes 3, 6, 7, and 8. Only those with brain metastases had 11q and/or 17q involvement in six of eight patients. In reported cases of nonbrain metastases, when chromosome 11 was involved, the short arm was usually deleted or replaced through translocation; on the contrary, in reports on patients with brain metastases, the long arm of chromosome 11 was deleted at q23 or was the recipient of a translocation at q23, and/or 17q was present as an isochromosome. These aberrations were similar to those found in the patients with brain metastases in this report. Two patients undergoing brain resections did not show 11q or 17q aberrations, one near diploid with t(10;19) and the other near hexaploid with few structural rearrangements. The neural cell adhesion molecule gene is located near 11q23, and the neural growth factor receptor is located near 17q21-q22. The relevance of these genes to brain metastases in melanoma is under investigation.

Significance of both numerical and structural chromosomal abnormalities in clear cell sarcoma

We analyzed cytogenetically two cases of clear cell sarcoma. The t(12;22)(q13;q13) hypothesized to be characteristic of clear cell sarcoma was detected in one of the two cases. Although this translocation was not observed in the other case; trisomy of chromosome 22 was, as were other numerical abnormalities. This latter observation has also been described in other reported studies of clear cell sarcoma. These findings confirm the nonrandomness of t(12;22)(q13;q13) in clear cell sarcoma, but also suggest that in its absence other abnormalities of chromosome 22 are significant. Trisomy 8, noted in both cases we report, as well as in previous studies, also appears to play an important role in clear cell sarcoma.

Non-random abnormalities of chromosomes 3, 6, and 8 associated with posterior uveal melanoma

We present ten cases of posterior uveal melanoma which were karyotyped after short-term culture. One tumour had a normal chromosome complement. The remaining nine tumours were cytogenetically abnormal, with chromosomes 3, 6, 8, 11, and 13 most frequently involved. Abnormalities of chromosome 13 were seen in two cases, chromosome 11 in three cases, and chromosomes 3, 6, and 8 in five cases. Four tumours, all derived from the ciliary body, demonstrated monosomy 3 and i(8q), confirming the involvement of these aberrations with a subgroup of uveal melanomas arising from the ciliary body.

Cytogenetic findings in six posterior uveal melanomas: involvement of chromosomes 3, 6, and 8

Six posterior uveal melanomas were karyotyped after short-term culture. One had a normal chromosome complement; the remaining five had limited chromosome changes. Involvement of chromosomes 1 and 6 was noted in two and four cases, respectively, and three ciliary body tumours demonstrated both monosomy 3 and i(8q).

Monosomy 3 and isochromosome 8q in a uveal melanoma

Chromosome analysis of a locally invasive uveal melanoma revealed monosomy 3 and i(8q). Sublines with multiple copies of the i(8q) were also present. Loss of heterozygosity for genes on chromosome 3 and duplication of genes on 8q may play an important role in progression of uveal melanoma.

Chromosome abnormalities and fragile sites in human melanoma

Chromosome analysis in short-term lines of three primary and seven metastatic malignant melanomas showed aneuploid karyotypes with recurrent abnormalities of chromosomes 1 (five cell lines), 6 (nine cell lines), and 7 (six cell lines). The breakpoints observed on the rearranged chromosomes frequently coincided with loci of known oncogenes and fragile sites. Two of the cell lines were analyzed after xenograft into nude mice and showed the presence of the same chromosomal changes observed in the parental cell lines, indicating the stability of the karyotype. A tendency toward an increased chromosomal fragility in peripheral blood lymphocytes was observed in five melanoma patients compared to ten normal individuals. However, there was no increased level of expression of specific fragile sites corresponding to the breakpoints observed in melanoma cells.

Characterization of IIB-MEL-J: a new and highly heterogenous human melanoma cell line

A highly heterogeneous cell line, IIB-MEL-J, was established from a human metastatic melanoma. This cell line contains small cells, dendritic cells, and megacells with multiple nuclei. IIB-MEL-J expresses S 100, cytokeratin intermediate filaments and the gangliosides GD2 and GD3. It requires growth factors (insulin, EGF, and transferrin) and antioxidants for optimal growth. When plated under optimal conditions, IIB-MEL-J grows with a doubling time of 70-80 hours. The cells may be fractionated by Percoll gradient centrifugation into several subpopulations (A, B, and C) with different characteristics. Subpopulation A is the slowest growing, and most of the DNA-synthesizing cells are concentrated in fractions B and C. Every subpopulation expresses S 100 and cytokeratin intermediate filaments, whereas only subpopulation B and C express GD2 and GD3. Pigmented cells are concentrated mainly in subpopulation C. Cytogenetic analysis of IIB-MEL-J revealed extensive chromosomal alterations, including a highly heterogeneous chromosome number and chromosomal rearrangements, gains, losses, isochromosomes, and double minutes. This highly heterogeneous cell line may be helpful to study cellular differentiation and interaction between different subpopulations in human melanoma.

Pigmented esthesioneuroblastoma showing dual differentiation following transplantation in nude mice. An immunohistochemical, electron microscopical, and cytogenetic analysis

Esthesioneuroblastoma (ESTH) is a neuroepithelial-cell-derived neoplasm of the olfactory mucosa composed of homogeneous small round cells which contain neurosecretory granules. Melanin has been detected in such tumours only occasionally. Here we describe a new case of ESTH with divergent differentiation. The primary neoplasm was found in a 67 year-old female, involving the left nasal and maxillary sinus; she died of cerebral metastasis ten months after diagnosis. Histologically only small round cells were seen, with S-100 and NSE positivity. Electron microscopy revealed neurosecretory granules and filaments, as well as the occasional presence of melanosomes. A nude mice xenograft line has been established, and is presently in its ninth transfer. Two cell types are present: small round-to-spindle shaped cells with neural features, and large epithelial-like ones. Both immunohistochemistry and electron microscopy confirm this dual differentiation, with the presence of membrane-bound dense-core neural secretion, as well as melanosomes of neuroectodermal origin. Additionally, an in vitro cell line has been established. Cytogenetic analysis confirmed the presence of both malignant human melanoma patterns; non-random abnormalities in chromosomes 1 and 6, extra copies of chromosome 7. Duplication of the long arm of chromosome 14, as seen in olfactory neuroblastoma, is also seen.

Malignant melanoma arising in a giant congenital melanocytic nevus. A case report with cytogenetic and histopathologic analyses

A malignant melanoma developed in a 2-year-old Hispanic girl with a giant congenital melanocytic nevus (bathing-trunk type). Histopathologic evaluation showed a deep-seated tumor arising from a nonepidermal origin. Cytogenetic analysis demonstrated multiple chromosomal abnormalities in hyperdiploid cells (chromosome range, 56 to 61). No two karyotypes were identical, but many abnormalities were common to all analyzed cells, suggesting both karyotypic instability and evolution. The metaphases were monosomic for 3, 12, and 16, trisomic for 1, 2, 8, 19, 20, and 21, and included structural aberrations deletion 1 and derivatives 3 and 16. Eight markers were identified, including one ring. The extra 19 was possibly an isochromosome. No abnormalities of 6 or 10 were identified.

Trisomy 6p in an ocular melanoma

Chromosome analysis of short-term culture of melanoma cells from a choroidal melanoma showed a karyotype of 46,XY, -21, +t(6p21q). Trisomy 6p has been observed in cutaneous melanomas; this case suggests that chromosome abnormalities in ocular melanomas may be similar to those from cutaneous melanoma.

Chromosome changes in metastatic human melanoma

Cytogenetic studies were performed on human malignant melanoma cells from eight metastatic lesions. Five tumors displayed near-triploid and three near-diploid chromosome numbers. Chromosomes #1, #6, #7, followed by #2 and #9, were found to be most frequently involved in structural aberrations. Aberrations involving chromosome #1, with deletions or translocations of 1p, involving region 1p12-1p22 in seven of eight breakpoints of the p arm were observed. Seven of nine breakpoints of 6q were located at region 6q15-6q21. Most of the breakpoints on chromosome #7 occurred near the centromeric region. All tumors had additional chromosome material involving 1q, chromosome #7 (7q in two tumors), and in five tumors an increased dose of chromosome #6 (6p in one tumor). The nonrandom breakpoints of these and other chromosomes involved diverse bands, including loci of oncogenes and fragile sites. The observation of nonrandom chromosomal changes in advanced malignant melanoma suggests that genes important in the progression of melanoma are located on chromosomes #1, #6, and #7.

Cytogenetic findings in an effusion secondary from pleural mesothelioma

Cytogenetic analysis was performed on cells from pleural effusion secondary to an epithelial mesothelioma. Although chromosomal findings (pseudodiploid stemline, including marker chromosomes involving chromosomes #1, #3, #5, and #6) suggested the neoplastic origin of the effusion, routine cytologic diagnosis was negative.

The involvement of 6p in melanoma

Karyotype analysis of first passage cells from a melanoma, occurring in a patient with a giant congenital nevus, revealed monosomy of chromosomes #6 and #11, and trisomy of chromosomes #8 and #22. Five marker chromosomes were present, including two ring chromosomes. The origin of three of the marker chromosomes was determined, and all were found to contain the region 6p21.1-6p23. The ring chromosomes were also thought to contain this region, to which the major histocompatibility locus has been mapped. The significance of these findings is discussed in the light of recent reports of chromosome studies of melanoma cells.