Ezrin in primary cutaneous melanoma.

Ezrin is a member of the ezrin-radixin-moesin family of proteins that link the actin-containing cytoskeleton to the plasma membrane. Ezrin is also connected to signaling molecules involved in the regulation of cell survival, proliferation and migration. Here, we examined the expression of ezrin in 95 primary cutaneous melanomas and correlated ezrin expression with conventional prognostic factors and biomarkers. From 12 patients metastatic tissue samples were also examined. In addition to ezrin staining, Mib-1 proliferation antigen, p53 and Bcl-2 were evaluated. Ezrin immunoreactivity was seen in most tumors; only 19 (20%) melanomas were negative. A total of 48 (51%) tumors had weak immunoreactivity and 28 (29%) strong immunoreactivity. The intensity of ezrin immunoreactivity was associated with tumor thickness (Breslow, P=0.0008) and with tumor invasion level (Clark, P=0.004), thicker tumors having stronger immunoreactivity. Also, there was a correlation between higher Mib-1 index in tumors and strong ezrin expression. All metastatic samples (n=12) showed positive ezrin immunoreactivity. In univariate analysis of survival, patients (n=76) with positive ezrin immunoreactivity had worse clinical disease behavior than those (n=19) without ezrin immunoreactivity, but the difference was not significant (P=0.19). In multivariate analysis of survival, the ezrin immunoreactivity was not a significant marker. The results indicate that ezrin is expressed in most primary melanomas of the skin and in all metastatic tumors. Ezrin expression correlates with tumor thickness and level of invasion suggesting an association between ezrin expression and tumor progression.     

Pagetoid infiltration in primary cutaneous melanoma

Pagetoid infiltration of the epidermis by melanocytes, also termed 'buckshot spread', is regarded by some as being essential for the confident histopathological diagnosis of primary cutaneous melanoma. We have reviewed 340 melanomas received over a 23 year period to assess the frequency of pagetoid infiltration and whether its presence bears any relationship with other histopathological features. Conspicuous pagetoid infiltration was present in 32.1% of the lesions and occasional melanocytes were observed within the stratum spinosum in a further 23.5% of cases. However, no melanocytes could be seen above the basal layer in 44.4% of the melanomas. The presence of pagetoid infiltration showed inverse correlation with tumour thickness, level of invasion, growth phase and mitotic count, and positive correlation with the presence and severity of regression. No association was found with the site of the primary lesion, melanocytic dysplasia or lentigo maligna in the adjacent epidermis, or with the presence of residual benign naevus cells in the epidermis. Thus, pagetoid infiltration of the epidermis was commonest in in situ or thin horizontal growth phase melanomas, and was conspicuous in only one-third of cases. While its presence is useful in the diagnosis of melanoma, its absence should not preclude it.     

散发性乳腺癌和乳腺增生细胞8p、16q微卫星DNA位点的杂合性缺失

目的研究散发性乳腺癌细胞和乳腺增生细胞中位于8p和16q的3个微卫星DNA(microsatellite,MS)位点D8S264、D8S258、D16S413的杂合性缺失(loss of heterozygosity,LOH)的频率;探索3个MS的LOH频率同乳腺癌淋巴结转移状态的关系。方法分离乳腺癌和乳腺增生病理切片上的病变细胞和正常对照细胞并分别提取DNA,采用PCR-变性PAGE电泳检测18例单纯增生(usual hyperplasia,UH)、15例不典型增生(atypical hyperplasia,AH)以及35例浸润性乳腺导管癌(invasive ductalcarcinoma,IDC)细胞中位于8p的D8S264、D8S258和位于16q的D16S413位点的LOH频率。结果 UH、AH、IDC组发生D8S264、D8S258和D16S413的LOH频率分别为7.1%、0、0,18.2%、11.1%、20%和42.8%、32%、34.7%,除D16S413外,IDC组的D8S264和D8S258的LOH频率明显高于UH组和AH组(P0.05);UH、AH、IDC组3个MS位点总LOH频率分别为5.6%、40%、57.1%,UH组与其余两组的差异有统计学意义(P0.05),AH与IDC组差异无统计学意义(P0.05);淋巴结转移阳性组和阴性组D8S264、D8S258、D16413的LOH频率及总LOH频率分别为36.4%、28.6%、42.9%、55.6%和47.1%、33.3%、31.7%、58.3%,组间的差异均无统计学意义(P0.05)。结论 IDC组频繁发生D8S264、D8S258、D16413的LOH,UH和AH组也发生了不同程度的LOH,其中发生于UH组的D8S264以及较高频率发生于AH组的D16S413值得关注和进一步研究;AH组与IDC组的3个MS位点总LOH频率较接近;D8S264、D8S258、D16413的LOH与淋巴结转移状态无关。     

The vascularity of primary cutaneous melanoma

In primary cutaneous malignant melanoma, the vascularity of the dermis immediately deep to the lesion may relate to tumour aggressiveness and to prognosis. These newly formed dermal vessels are incorporated into the melanoma to form the tumour microcirculation. We have assessed the percentage vascular volume in a series of primary melanomas in order to investigate the relationship between tumour vascularity and maximum tumour thickness. For the 64 melanomas included in this study, there appeared to be a significant relationship between the percentage vascular volume and the maximum tumour thickness. This relationship was not influenced by the presence of necrosis, vascular invasion, regression, or lymphocytic infiltrate, nor by the growth phase of the tumour. However, the percentage vascular volume was very low in the occasional thick melanoma, at least one of which was associated with prolonged survival. It seems possible that a low tumour vascularity could correlate with a relatively favourable outcome in cutaneous melanoma.     

Loss of heterozygosity of DPC4 tumor suppressor gene in human sporadic colon cancer

We investigated the prevalence of DPC4 loss of heterozygosity in sporadic colorectal cancer. Thirty-six cases of human sporadic colon carcinoma and corresponding normal tissue samples were examined to evaluate loss of heterozygosity at the DPC4 tumor suppressor locus using variable nucleotide tandem repeat (VNTR) analysis and three polymorphic markers. From 36 analyzed samples 35 (97%) were heterozygous or informative. Loss of heterozygosity at the DPC4 locus was detected in 18 (51%) of informative tumor DNAs. The DPC4 LOH was more frequent in smaller tumors (<5 cm) than in larger ones. There was no correlation between DPC4 LOH and age or sex of patients. There was a negative correlation between DPC4 LOH and histological grade or Dukes' stage of tumors, but without statistic significance. Observed results are in agreement with the view that malignant progression is consequence of many genetic changes. It can be concluded that inactivation of the DPC4 gene plays a role in a multistep process of outgrowth and progression of colon cancer.     

Myxoid variant of primary cutaneous malignant melanoma

We report a rare case of primary cutaneous myxoid melanoma. Histologically, the tumour was composed of spindle and stellate-shaped cells, embedded in a myxoid stroma. Positivity for S-100 protein and the presence of melanosomes were demonstrated in the tumour. Primary cutaneous myxoid melanoma is rare. This is the second report of such a case.     

Loss of heterozygosity of APC and DCC tumor suppressor genes in human sporadic colon cancer

We examined 36 cases of human sporadic colon carcinoma and corresponding normal tissue samples to evaluate loss of heterozygosity at the APC and DCC tumor suppressor genes loci using restriction fragment length polymorphism polymerase chain reaction and variable nucleotide tandem repeat analysis. Observed informativity was 83% for APC and 75% for DCC. DNA from 6 (20%) of 30 informative tumors exhibited loss of heterozygosity at the APC locus. Loss of heterozygosity at the DCC locus was observed in 7 (26%) of 27 informative tumor DNAs. Our results support the view that malignant progression is a consequence of more than one genetic change and suggest that inactivation of APC and DCC genes plays a role in a multistep process of colon tumor progression. Received: 7 August 1998 / Accepted: 15 December 1998     

Loss of heterozygosity at cylindromatosis gene locus, CYLD, in sporadic skin adnexal tumours

AIM: The gene for familial cylindromatosis (CYLD) has been localised to chromosome 16q, and has recently been cloned. Loss of heterozygosity (LOH) at 16q has also been demonstrated in sporadic cylindromas. The aim of this study was to investigate whether CYLD plays a role in the development of other skin appendage tumours. METHODS: A total of 55 cases of skin adnexal tumours, comprising 12 different types, and a control group of 14 squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs) were studied. Three microsatellites (D16S407 (16p), D16S304 (16q), and D16S308 (16q)) were analysed for LOH after microdissection from paraffin wax embedded sections using laser capture microdissection. RESULTS: In keeping with previous data, a proportion of cylindromas exhibited LOH at markers on 16q, but not at 16p. The skin adnexal tumours showing a similar pattern included apocrine hydrocystomas, eccrine spiradenomas, and sebaceous adenoma. One case of syringoma showed LOH at 16q, and a further case at 16p, but not 16q. One case of eccrine hydrocystoma showed loss at 16p, but not 16q. The remaining tumours were either negative or non-informative. All tumours in the control group were either negative or non-informative, except for a single case of BCC showing LOH at 16q. CONCLUSION: CYLD may be involved in the development of skin adnexal tumours other than cylindromas.     

Loss of heterozygosity analysis of cutaneous melanoma and benign melanocytic nevi: laser capture microdissection demonstrates clonal genetic changes in acquired nevocellular nevi

The molecular pathology of the common nevocellular nevus (NCN) and its relationship to the genetic model of malignant melanoma (MM) progression has not been fully characterized. We used laser capture microdissection of archival formalin-fixed material to study 34 melanocytic lesions (19 MM and 15 NCN). Twelve of the 15 NCN were acquired, 3 of which were congenital; none had dysplastic features. Ten polymorphic markers on five chromosomal regions (1p36, 6q22-23.3, 8p22-24, 10q23, and 11q23) were selected for loss of heterozygosity (LOH) analysis, based on previous studies demonstrating involvement in MM pathogenesis and progression. Loss of heterozygosity at any allelic locus was observed in 18 of 19 (95%) MM and in 9 of 15 (60%) NCN. Of the three congenital nevi analyzed, none showed LOH at any informative locus. The frequency of allelic loss was highest in the MM at 6q22-23.3 (64%), followed by 10q23 (62%), 8p22-24 (43%), 11q23 (43%), and 1p36 (13%). In the 15 NCN, the most frequent allelic losses were detected at 6q22-23.3 (29%), 1p36 (27%), and 10q23 (25%), with lower frequencies of LOH at 11q23 (10%) and 8p22-24 (7%). LOH at a single polymorphic marker, D6S1038, was detected in 70% of the MM and in 36% of the NCN, suggesting the presence of putative tumor-suppressor genes (TSGs) critical in melanocytic neoplasia at 6q22-23.3. The presence of clonal genetic alterations in acquired NCN justifies their classification as a benign neoplasm. The pattern of LOH in NCN is not random; rather, the relative frequencies of LOH at the chromosomal regions examined are consistent with a multistep model of MM progression that begins with NCN. Molecular analysis of NCN reiterates established epidemiologic and morphologic notions that NCN are precursor lesions for MM.     

Current state of treatment for primary cutaneous melanoma

Abstract. The incidence of malignant melanoma has been rising steadily for the last 30 years. Through physician and patient education, surveillance of high-risk individuals, and biopsy of any suspicious lesions, more lesions are being diagnosed earlier, where there is a high cure rate. Unfortunately many patients will still present with thicker lesions or nodal involvement, which carries a significantly worse prognosis. Over the past decade, there have been several changes in the management of primary cutaneous melanoma. These have stemmed from novel surgical approaches, a new understanding of melanoma biology, and randomized clinical trials designed to improve outcome and decrease the morbidity of therapy. This article will review the clinical evidence behind the current treatment recommendations for primary cutaneous melanoma as well as some of the emerging data on innovative immunologic-approaches to melanoma treatment.     

Genotypic analysis of primary and metastatic cutaneous melanoma

Microdissection genotyping was performed on 16 cases of melanoma, including two cutaneous and one lymph node metastases. Three benign nevi were used as controls. Where possible, tumor was microdissected at several sites. Genotyping involved assessment of loss of heterozygosity [LOH]), which was accomplished using a panel of nine polymorphic tetranucleotide microsatellites. Polymerase chain reaction was performed on the normal tissue sample to establish microsatellite heterozygous status. Informative markers were then tested on microdissected lesional tissue and scored for the presence and extent of allelic imbalance (AI). Microsatellite informativeness varied from 33% to 66%. Benign nevi were without AI. All invasive melanomas manifested acquired allelic loss, which involved 75% or 100% of the markers shown to be informative for each subject. Eleven of 13 (84%) primary melanomas demonstrated intratumoral heterogeneity of AI consistent with development of tumor subclones with differing genotypic profiles within thin as well as thick melanomas. Although a consistent pattern did not emerge among the markers, LOH of 9p21 (D9S254) occurred in 60% (9/15) of the cases followed by 40% of cases displaying LOH of 1p34, p53, 10q (MXI1), and 10q23 (D10S520) and 25% with 5q21 (D5S 592) abnormalities. A third of the cases including the metastatic foci demonstrated two different patterns of AI affecting alternative alleles of the same genomic marker within different parts of the melanoma. Two melanomas in situ did not display LOH of any markers in the informative cases although the in situ component in the invasive tumors had allelic losses that were in part similar to the invasive areas. The results of this study support the expanded use of microdissection genotyping and explore other markers to define the unique mutational profile for malignant melanoma that may complement other histologic characteristics of melanoma.     

Loss of heterozygosity in the MXI1 gene is a frequent occurrence in melanoma.

Melanoma development and progression is thought to be the result of a multi-step accumulation of genetic damage, with loss of heterozygosity in chromosome 9p (MTS1) frequently described. In addition, chromosome 10q allelic loss has been reported, implicating the tumor suppressor gene PTEN/MMAC1 on 10q23.3. The MXI1 gene at 10q24-25 is another candidate tumor suppressor that has only rarely been studied in melanomas, with conflicting results. We used microdissection-based genotyping to investigate 29 melanomas from 20 patients for loss of heterozygosity in intragenic and flanking microsatellite markers for this latter gene. Concurrently, the MTS1 gene was similarly studied using two flanking microsatellites. Fifty-four percent (15 of 28) of the informative cases showed loss of heterozygosity for one or both MXI1 markers, as compared with 67% (16 of 24) of the informative cases for MTS1. MXI1 allelic loss was seen more frequently in recurrent/metastatic tumors (59%), as compared with in primary (33%) lesions. Eighty percent of the primary tumors showed loss of heterozygosity for MTS1, as well as 63% of recurrent/metastatic ones. We studied more than one tumor in eight patients, with those from three patients showing discordant genetic patterns. One patient showed a metastatic tumor with allelic loss for MXI1 that was not identified in the primary melanoma or a local recurrence. The other two patients showed clonal heterogeneity in MXI1 at synchronous and metachronous metastatic foci. These findings support MXI1 as a putative tumor suppressor gene involved in conventional melanoma progression. Genetic heterogeneity seen in different metastases from the same primary suggests a nonlinear pattern of chromosomal damage, with the development of multiple clones within the primary tumor, each acquiring its own metastatic potential.     

Cytologic features of metastatic and recurrent melanoma in patients with primary cutaneous desmoplastic melanoma

Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by malignant spindle cells associated with prominent fibrocollagenous stroma. Primary melanomas may be entirely desmoplastic ("pure" DM) or exhibit a desmoplastic component admixed with a nondesmoplastic component ("combined" DM). The cytologic features of only 5 cases of DM have been reported previously. Fine-needle biopsy (FNB) specimens from 20 recurrent or metastatic lesions in patients with cutaneous DM and 20 recurrent or metastatic lesions from patients with primary cutaneous non-DM were examined and compared. FNB specimens of patients with DM were less cellular (P = .009) and less often exhibited intranuclear cytoplasmic invaginations (P = .008) and mitotic figures (P = .006) than specimens from patients with non-DM. "Combined" DMs were more commonly composed of epithelioid cells (P = .017) and less often contained bizarre/giant tumor cells (P = .010) than did "pure" DMs. Recurrent and metastatic DM has a range of cytologic appearances. Awareness of the cytologic features and careful clinicopathologic correlation will assist in accurate FNB diagnosis.     

Loss of heterozygosity of MCC is not associated with mutation of the retained allele in sporadic colorectal cancer

The adenomatous polyposis coli (APC) gene, which transmits familialadenomatous polyposis, is frequently mutated in sporadic colorectaltumours. Acquired somatic mutations have also been reportedin a second gene, mutated in colorectal cancer (MCC), whichlies within 500 kb of APC on chromosome 5q21 and has thus beenImplicated In tumour development. Further evidence for an oncosuppressorgene other than APC on chromosome 5q comes from recent studiesof lung, renal and hepatic cancers in which there Is loss ofheterozygosity of 5q21 but no somatic APC mutations. To investigatethe relative importance of APC and MCC In sporadic colorectalcancer, we have assessed the extent of 5q21 allellc loss in80 carcinomas. All informative tumours exhibiting allellc losshad deletions which included both APC and MCC. In 21 tumourswith loss of heterozygosity In MCC we have screened the entirecoding region of the gene for mutation of the retained alleleand found no evidence for mutation. The data Indicate that independentloss of MCC Is a rare event, and that in cases where alleleloss occurs mutation of the retained allele Is uncommon. Thissuggests that MCC does not function as an independent tumoursuppressor In the majority of colorectal cancers.     

Malignant peripheral nerve sheath tumour-like primary cutaneous malignant melanoma

Malignant melanoma is known for its protean cytomorphological features, architectural patterns, and stromal changes, in addition to its ability to mimic various benign and malignant non-melanocytic tumours. Anecdotal cases of metastatic malignant melanoma simulating soft tissue sarcomas have been reported. Interestingly, this mimicry is more often seen in recurrent lesions and metastatic deposits. This report describes a case of a primary spindle cell cutaneous malignant melanoma with a prominent neural-like fascicular pattern and nuclear palisading, simulating a conventional malignant peripheral nerve sheath tumour (MPNST). Clinical, microscopic, and immunohistochemical features of the different entities included in the differential diagnosis of cutaneous spindle cell malignant tumours, such as MPNST, atypical fibroxanthoma, and spindle cell squamous cell carcinoma are discussed. Of note, the presence of an atypical epidermal or junctional component, cell pigmentation, and cell nesting, in addition to diffuse and strong reactivity for S-100 protein and other melanocytic markers, are helpful in the diagnosis of these troublesome lesions.     

Histological type and biological behavior of primary cutaneous malignant melanoma

Summary Primary cutaneous malignant melanomas are generally divided into 3 separate clinico-pathological variants, lentigo maligna melanoma (LMM), superficial spreading melanoma (SSM), and nodular melanoma (NM). Recently an additional variant, acral lentiginous melanoma (ALM), has been defined, occurring on acral regions, defined as plantar, palmar, and sub-/parungual areas. Histological examination of 86 primary melanomas on acral regions revealed 24 (28%) acral lentiginous melanomas (ALM), 23 (27%) superficial spreading melanomas (SSM), 18 (21%) nodular melanomas (NM), and 21 (24%) unclassifiable melanomas. No LMM was seen. The prognosis was found to be the same in patients with SSM and ALM. However, by correlating histological type with frequency of antecedent nevus, duration of melanoma and dominant invasive tumor cell, it was demonstrated that histologically typical ALM differed from histologically typical SSM by their infrequent origin from antecedent nevi, their lower local growth rate, and their more frequent content of spindle cells. These findings support ALM as a valid melanoma subtype only when clearly defined histologically.