Clinical and pathological features of metastases of primary cutaneous desmoplastic melanoma

Murali R, Zannino D, Synnott M, McCarthy S W, Thompson J F & Scolyer R A
(2011) Histopathology  58 , 886–895
Clinical and pathological features of metastases of primary cutaneous desmoplastic melanoma Aims: Primary cutaneous desmoplastic melanoma (DM) may be entirely desmoplastic [‘pure’ DM (pDM)] or exhibit a desmoplastic component admixed with a non‐desmoplastic component [‘combined’ DM (cDM)]. Our aim was to describe the histological features of metastases of primary DM and to determine whether they were predictive of outcome. Methods: The effect of clinicopathological parameters on overall survival (OS) was analysed, and the correlation between histological features of the primary melanoma and metastases was studied in patients with metastatic DM. Results: Twenty‐six patients (18 males; eight females) developed 50 metastases in sentinel nodes (13; 26.0%), regional nodes (10; 20.0%), skin (14; 28.0%), and distant sites (13; 26.0%). The cellular composition of metastases correlated with that of the corresponding primary tumours. Time to development of first non‐sentinel lymph node metastasis was shorter in cDM than in pDM (median 11.2 versus 24.9 months, P = 0.075). The only independent predictors of poorer OS were cDM type [hazard ratio 6.17, 95% confidence interval (CI) 1.61–23.81, P = 0.008] and male sex (hazard ratio 5.98, 95% CI 1.34–26.66, P = 0.019). Conclusions: The cellular composition of primary DM correlates with that of metastatic DM and with outcome. It is important to consider the possibility of primary or metastatic DM when examining tumours composed of spindle cells.     

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.     

Cytomorphologic features of fine-needle aspiration of metastatic and recurrent melanoma

Melanoma is an aggressive malignancy with a growing prevalence. Although early detection and excision offer a potential cure, recurrences and metastases are not uncommon. Fine-needle aspiration (FNA) can play a vital role in their detection as a relatively noninvasive, rapid, and economical alternative for tracking disease evolution. Prior clinical history and classic cytological features of melanoma (loosely cohesive smear pattern and single cells with large nuclei, prominent nucleoli, and melanin pigment) aid in cytological diagnoses. However, not all melanomas contain melanin pigment or characteristic cytologic features. We examined a large series of melanoma cases to determine the incidence of melanin pigment, the most common cell morphology, and the presence or absence of apoptosis/necrosis associated with this highly aggressive neoplasm.     

The morphological features of locally recurrent melanoma and cutaneous metastases of melanoma.

Local recurrence of melanoma at the primary excision site usually implies that the primary excision was incomplete or "inadequate" and that the recurrence was attributable to retained primary melanoma cells or occult melanoma metastases in the adjacent tissue. Pathologists frequently report these tumors in the scar as recurrent or residual melanoma, apparently without considering the possibility that they may be local metastases and manifestations of systemic disease. In this study of 72 cases, we have shown that the morphological features of locally recurrent melanoma, excluding persistent incompletely excised primary melanoma, and cutaneous metastases of melanoma were identical. Because the prevention of local recurrence is the main reason for wide excision of melanoma beyond complete excision of the primary tumor itself, it is essential that pathologists should classify these neoplasms precisely as either persistent incompletely excised primary melanoma or metastatic melanoma.     

Cytologic features of metastatic nasopharyngeal carcinoma

The aim of the study was to describe the cytologic features of metastatic nasopharyngeal carcinomas (NPC) to lymph node, which would help in arriving at a definite diagnosis, particularly in cases of occult primary with predominant finding of cervical lymphadenopathy. This is a retrospective study over a period of 2 yr (January 2000 to December 2001) and included 15 cases of NPC metastasizing to cervical lymph nodes. All cases had histopathologic diagnosis of primary NPC. Two independent observers studied detailed cytomorphology of these cases. The FNAC smears were cellular and except for three cases revealed predominantly discohesive malignant cells admixed with lymphocytes. Cellular degeneration and naked tumor cell nuclear were seen in all cases. The tumor cells showed mild to moderate nuclear pleomorphism, vesicular chromatin, and scanty cytoplasm with ill-defined cytoplasmic borders. All 15 cases were typed according to the World Health Organization (WHO) classification as types I, II, and III NPCs. There were two cases of type I NPCs, five cases of type II, and eight cases of type III pattern. FNAC of metastatic NPC in lymph node is a valuable diagnostic modality in suggesting the site of origin of the tumor. Furthermore, it is also helpful to exclude residual disease and recurrence in a treated patient with lymphadenopathy.     

Cytologic features of metastatic transitional cell carcinoma

Cytologic preparations containing metastatic transitional cell carcinoma (MTCC) from 18 sites in 16 patients were renewed to determine characteristic morphologic features. The patient group included 13 males and 3 females with a mean age of 66 years. Primary TCC occurred in the bladder (14), kidney (1) and ureter (1); nearly all the primary tumors were poorly differentiated and most were invasive at the time of diagnosis. The cytologic specimens were derived from lymph nodes (6). liver (4). serous fluids (2), pelvic soft tissue (2), subcutaneous nodules (2), and lung (1). One patient presented with MTCC in Pap smears. Cytologically MTCC presented as loosely cohesive, moderate to markedly pleomorphic cells which occurred singly and in syncytial clusters. The malignant cells were usually large with abundant granular or fibrillar cytoplasm and the cell borders were generally distinct. Most nuclei were large and hyperchromatic with irregularly distributed granular chromatin and prominent nucleoli. The most distinctive features were the presence of spindled, pyramidal, and/or racquet-shaped malignant cells with eccentric nuclei and cytoplasmic features of both squamous and glandular differentiation including endoplasmic/ectoplasmic interfaces and intracytoplasmic vacuoles. Although clinical history is most useful in the diagnosis of MTCC, these morphologic features in cytologic preparations of malignant epithelial neoplasms may be helpful. In the absence of a known primary TCC. it is doubtful that a definite cytologic diagnosis could be made; however, the characteristic cell shapes and cytoplasmic features may be suggestive of MTCC.     

Cell migration and actin organization in cultured human primary, recurrent cutaneous and metastatic melanoma. Time-lapse and image analysis.

Random cell migration and actin organization in seven human primary, recurrent cutaneous, and metastatic melanoma cell lines were studied by time-lapse video recording and image analysis. The migration of over 800 randomly selected cells from the cell lines were recorded using an inverted microscope with an attached incubator housing. The fraction of cells with random migration rates greater than 10 microns/hour was 8% in an established primary melanoma cell line, 2% and 34% in two recurrent cutaneous melanoma cell lines, and 5%, 30%, 31%, and 60% in four metastatic cell lines. The three metastatic cell lines with significantly higher mean migration rates (P less than 0.001) were derived from lymph node metastases, whereas the fourth metastatic cell line was derived from a visceral metastasis. The cellular morphology and presence of cell nests in the original tissue correlated with in vitro cell morphology and the formation of colonies. The ability of cells to organize actin into stress fibers directly correlated with significantly higher random migration rates and lack of colony formation. Characterization of random migration rates and actin organization of human melanoma cells that are isolated from different stages of tumor progression may lend insight into metastasis.     

Cell kinetics of melanocytes in common and dysplastic nevi and in primary and metastatic cutaneous melanoma.

The 3H-thymidine labelling (LI) and mitotic (MI) indexes were calculated in 29 cutaneous melanocytic lesions: 6 common nevi (CN), 11 dysplastic nevi, subclassified as nevi with architectural atypia (NAA = 4) and nevi with cyto-architectural atypia (NCAA = 7), 2 melanomas in situ (MIS), 4 invasive superficial spreading melanomas (IM) and 6 metastatic melanomas (MM). The LI mean values resulted to be: CN = 0.23%, NAA = 0.98%, NCAA = 1.79%, MIS = 5.75%, IM = 5.16%, MM = 3.80%. In CN, NAA, NCAA and MIS, these values were calculated at epidermal level; in IM and MM at dermal level. At dermal level, the LI mean values of CN, NAA and NCAA were: 0.20%, 0.20%, 0.23% respectively. The MI mean value was close to 0 in CN, NAA, NCAA, MIS; 0.18% in IM, 0.16% in MM. Confirming a low proliferative activity in CN and a high activity in melanomas (MIS, IM, MM), the results showed that dysplastic nevi (NAA, NCAA) had a proliferative activity intermediate between common nevi and melanomas. The lesions with melanocytic atypia (NCAA) resulted to have a higher proliferative activity than those without this histological feature (NAA).     

Cytologic features of recurrent lymphoma involving the urinary bladder

Recurrent lymphoma of the bladder only occasionally presents with genitourinary symptoms, and there are very few cases in the literature reporting the cytologic findings of involvement of the urinary bladder by lymphoma. We report the findings from a case of diffuse large B-cell lymphoma with immunoblastic morphology that was identified in a bladder barbotage specimen of a 77-year-old man who presented with recurrent urinary tract infection and hematuria. We describe the cytomorphological features of lymphoma cells in the urine and discuss the differential diagnoses. Correlation of cytologic findings with immunohistochemical results is crucial in the diagnosis of lymphoma involving the urinary bladder.     

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.     

Identification of genetic disparity between primary and metastatic melanoma in human patients

It is commonly accepted that cancer cell progression is accompanied by accumulation of genetic changes. Here we searched for copy number variations in melanoma and asked whether homozygous losses always cumulate during tumor cell progression. Therefore we investigated either melanoma cell lines or tissue derived from the primary lesion and from the lymph node metastasis of the same individual patient. In vitro studies of melanoma cell lines revealed high migratory and anchorage independent growth of metastasis-derived cells. Surprisingly, whole genome DNA analysis of a primum-derived cell line revealed a total of 10 homozygous losses, whereas the matched metastasis-derived cell line only shared five of those losses. We further tested these cells in a mouse model for intradermal melanoma growth and detected fast growth of the metastasis-derived cell line and no growth of primum-derived cells. Additionally, we screened matched pairs of patient-derived melanoma primum and metastasis samples and we could also identify a case with homozygous deletions exclusively present in the primary lesion. Therefore, we suggest that tumor cell progression at the metastatic niche can occur parallel and independently from the primary tumor. We propose that for mutation-targeted therapy genotyping should be performed not only from primary, but also from metastatic melanoma.     

Cytologic prints of primary and metastatic melanomas. Preliminary report

In 15 cases of melanoma (10 primary tumours and 5 metastatic ones) imprint examination was performed intraoperatively. In one case the material was non-diagnostic. Out of the remaining 14 cases six tumours consisted of epithelioid cells, one--spindle-shaped and seven were of mixed structure. Typical characteristics of the imprint included cellular dispersion, polymorphism, presence of binuclear and giant cells as well as intranuclear cytoplasmic inclusions. There features are the same as those described in other cytologic studies of these neoplasms. The imprints method turned out to be useful as an accessory and complementary study intraoperative histopathologic examination.     

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 in sporadic primary cutaneous melanoma

Difficulties in obtaining clinical samples from primary melanomas have meant that most genetic analyses of melanoma have concentrated on cell lines and metastases. Because the Breslow thickness of the primary tumour is the single best prognostic indicator, it is important to identify genetic abnormalities in primary melanomas and relate these changes to the thickness of the lesion. We have investigated 47 sporadic melanomas, of which 41 were primary lesions, for loss of heterozygosity (LOH) on several chromosomal arms, including areas where genes involved in familial melanoma and other relevant hereditary syndromes map, and where LOH has previously been reported in cell lines or metastatic lesions. LOH was identified at 66 (18%) of 358 informative loci in primary melanomas, and there was a significant relationship between the overall frequency of LOH and Breslow thickness (P < 0.0005). Loss of chromosome arm 9p was most frequent, occurring in 15 (47%) of 32 informative primary tumours, and was observed in 3 of 11 informative lesions ≦ 1.5 mm in depth. LOH on chromosome arms 3p, 6q, 10q, 11q, and 17p was also relatively frequent, with loss of 3p and 10q heterozygosity in lesions ≦ 1.5 mm in depth, while LOH on 6q, 11q, and 17p was only detected in more invasive tumours. The results suggest that loss of these chromosome regions are important in sporadic cutaneous melanoma, and are consistent with chromosome arm 9p loss occurring before loss of other chromosome arms.     

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.