Aggressive Ciliary Body Adenocarcinoma with Bilateral Lung Metastases: Histological, Molecular, Genetic and Clinical Aspects.

PURPOSE OF THE STUDY: To describe the clinical and histopathological features of an aggressive ciliary body adenocarcinoma with pulmonary metastases and skull base spread. PROCEDURES AND RESULTS: A 45-year-old female patient presented with a post-traumatic phthisical eye that was eviscerated. This showed an unexpected carcinoma (positive for cytokeratins and melanocytic markers), the histological differential diagnosis for which included a primary ciliary body adenocarcinoma or a metastasis. The patient developed rapid post-surgical localized recurrence that required an orbital exenteration. This showed identical tumour to the evisceration specimen, with vascular invasion in orbital blood vessels and a contaminated orbital soft tissue margin. Staging imaging revealed multiple lung metastases, which were biopsied and shown to be a disseminated ciliary body adenocarcinoma rather than a disseminated primary lung carcinoma. The tumour spread locally to the skull base for which radiotherapy was given. Unfortunately, the patient passed away a few weeks later. CONCLUSIONS: To our knowledge, this is the first case of ciliary body adenocarcinoma with bilateral lung metastases. The malignant potential of these tumours should be considered as a possibility, and appropriate screening and staging tests should therefore be considered to guide appropriate management.

Phenotypic Plasticity in Uveal Melanoma Is Not Restricted to a Tumor Subpopulation and Is Unrelated to Cancer Stem Cell Characteristics.

Purpose: Uveal melanoma (UM) is the most common primary intraocular malignancy in adults and approximately half of those diagnosed will die of metastasis. This study investigates whether UM progression is driven by a subpopulation of stem-like cells, termed "cancer stem cells" (CSCs). Methods: Expression of postulated stem cell markers aldehyde dehydrogenase (ALDH), CD44, and CD133 was analyzed in UM cell lines and primary UM short-term cultures (STCs) established from tumor samples. Additionally, the notion of a "cellular hierarchy" within UM was investigated. Finally, the phenomenon of phenotypic plasticity in response to environmental factors was explored. Results: We demonstrate that expression of ALDH, CD44, and CD133 does not select for a subpopulation of stem-like cells in either UM cell lines or UM STCs. Furthermore, there is an absence of a cellular hierarchy in cell lines and all cells in culture are able to drive tumor progression. Last, we show that established UM cell lines and UM STCs are plastic in nature and switch their phenotype in response to environmental stimuli. Conclusions: We hypothesize that this capacity to undergo phenotypic plasticity may be a consequence of neural crest lineage and renders the exploration of the CSC hypothesis extremely challenging in UM.

High-Resolution Array CGH Analysis Identifies Regional Deletions and Amplifications of Chromosome 8 in Uveal Melanoma.

PURPOSE: Monosomy 3 (M3) and abnormalities of chromosome 8 associate with poor prognosis in uveal melanomas (UM). Although M3 has been the subject of more in-depth studies, none have intensively focused on chromosome 8. To elucidate the potential role of chromosome 8 abnormalities, array comparative genomic hybridization (aCGH) was performed on primary UM. METHODS: A specifically-designed custom high-resolution array was developed focusing on changes most implicated in UM. Probes for chromosome 8 had a mean spacing of 2.3 kb while chromosomes infrequently affected had a mean spacing of 36.6 kb. A series of 75 UM, including one formalin-fixed paraffin sample were analyzed, and where possible control DNA extracted from the patient's own peripheral blood was used. RESULTS: The most common copy number abnormalities were chromosome 8 (75%) and M3 (51%), with M3 and gain of the long arm of chromosome 8 (8q+) associated in 41% of cases. Also identified were partial deletions of chromosome 3 (3%) and regional 8q+ (23%), and the intensive coverage of chromosome 8 revealed small focal deletions and amplifications affecting both arms. The most significant predictor of prognosis was M3/8q+ having a hazard ratio of 10.1 (P < 0.0001). CONCLUSIONS: Neither 8p deletion nor focal changes affecting chromosome 8 were linked to outcome. The most significant indicator was M3/8q, and multiple 8q+ associated with shorter survival. Studying UM with this technology provides a powerful robust tool for predicting prognosis while considering other genetic changes, allowing the future incorporation of such data as it becomes clinically significant.

Common genetic changes in leiomyosarcoma and gastrointestinal stromal tumour: implication for ataxia telangiectasia mutated involvement.

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. Formerly GISTs were commonly classified histologically as leiomyosarcomas; however, they are now known to arise from the interstitial cells of Cajal. Majority of GISTs overexpress KIT and have characteristic mutations within the gene, which are the targets of drug treatment with tyrosine kinase inhibitors. Leiomyosarcoma is a malignant tumour of smooth muscle differentiation and falls into a group of sarcomas that show complex karyotypic changes with no consistent recurrent genetic abnormality. We have used comparative genomic hybridization in combination with fluorescence in situ hybridization to determine genetic differences between the tumour types. We found leiomyosarcomas and GISTs share common regions of chromosomal 13q and 11q imbalance, in addition to more specific 1p and 8p losses in leiomyosarcoma and 15q and 22q losses in GISTs. More importantly, we have shown for the first time a deletion in the ataxia telangiectasia mutated (ATM) gene locus with decreased/absent expression of ATM protein, and amplification in the region 13q21-q32 in both tumour types, suggesting both regions may play a role in leiomyosarcoma and GIST biology.

Transformed diffuse large B-cell lymphomas with gains of the discontinuous 12q12-14 amplicon display concurrent deregulation of CDK2, CDK4 and GADD153 genes.

Transformation of the indolent follicular lymphoma (FL) to the aggressive diffuse large B-cell lymphoma (DLBCL) results in resistance to therapy with shortened survival. It has been demonstrated that the 12q12-14 region was mainly amplified in DLBCL cases but not in their FL counterparts. Therefore, we examined the DNA copy number and protein expression profiles for CDK2, CDK4 and GADD153, three genes that map to 12q12-14, in a set of 44 paired FL/DLBCL samples from 22 patients. The concordant amplification of these genes occurred in seven of 22 (32%) of FL cases, compared with 15 of 22 (68%) of DLBCL cases. At the protein level, 15 of 22 of the DLBCL samples (68%) showed strong staining for the CDK2 protein, compared with five of 21 of FL samples (24%). The majority of the DLBCL samples (16/22, 72%) expressed the CDK4 protein, whereas the majority of the FL samples (12/21, 57%) showed no expression of this protein. Except for one DLBCL case, no expression of the GADD153 protein could be detected. The deregulation of the CDK2 and CDK4 genes at the genetic and protein levels suggest a functional role for these genes in the transformation process and could potentially provide targets for prognostic tests or therapeutic interventions.

Analysis of colorectal tumor progression by microdissection and comparative genomic hybridization.

This investigation aimed to identify patterns of copy number change in colorectal tumor progression from adenoma to liver metastasis. Fifty-three microdissected sub-regions from 17 cases of colorectal cancer were assigned to one of six histopathologically defined categories: coexisting adenoma, tumor above the muscularis layer, tumor within the muscularis layer, tumor extending through the bowel wall to serosal fat, lymph node metastasis, and liver metastasis. Microdissected samples were treated by a microwave processing step and then used as templates for universal PCR amplification. PCR products were fluorophore labeled and subjected to comparative genomic hybridization. Copy number changes were found in all samples, and every chromosome arm (excluding acrocentric short arms) was affected. More losses than gains were detected, but there were no significant differences between the numbers of changes seen in each category. Each individual sample revealed unique changes, additional to those shared within each case. The most frequently observed gains were of X and 12q. The most common losses were of 8p, 16p, 9p, 15q, 18q, and 10q. Nominally significant associations were observed between metastatic tumor and loss of 12q24.1 or 10p13-14, non-metastatic tumor and loss of 8q24.1, tumor extending to serosal fat and loss of 6q24-25 or gain of 4q11-13, tumor extending to serosal fat and metastatic lesions and loss of 4q32-34 or 22q11-12, and adenoma and loss of 15q24. Loss of 4q32-34 remained highly significant after correction for multiple testing. Adenoma was the only category not to show loss of 17p. These data reveal a genetically heterogeneous picture of tumor progression, with a small number of changes associated with advanced disease.

Identification of novel regions of amplification and deletion within mantle cell lymphoma DNA by comparative genomic hybridization.

We have carried out comparative genomic hybridization (CGH) analysis on archival biopsy material from a series of 30 UK mantle cell lymphomas. The most frequent aberrations were gains of 3q (21 cases), 6p (19 cases), 7q (8 cases), 12p (8 cases), 12q (9 cases) and 17q11q21 (8 cases), and losses of 1p13p32 (10 cases), 5p13p15.3 (9 cases), 6q14q27 (11 cases), 8p (7 cases), 11q13q23 (8 cases) and 13q (18 cases). Nineteen cases (63%) had a common region of amplification at 3q28q29, which was highly amplified in three cases, suggesting the presence of a mantle cell lymphoma (MCL)-related oncogene in this region. There was a minimal common region of deletion at 6q25q26 in nine cases (30%). No MCL-specific locus has previously been identified on chromosome 6 and this region may contain a tumour suppressor gene specifically implicated in the development of this subtype of lymphoma. An increased number of chromosome aberrations, gain of Xq and loss of 17p were all significantly associated with a worse prognosis. A greater understanding of the genetics of mantle cell lymphoma may allow the identification of prognostic factors which will aid the identification of appropriate treatment regimens.