Partial regression of primary cutaneous melanoma: is there an association with sub-clinical sentinel lymph node metastasis?

Multiple Primary Cutaneous Melanomas in a Bulgarian Patient: The Possible Role of One Step Melanoma Surgery (OSMS) As the Most Adequate Treatment Approach!

BACKGROUND:

Simultaneous occurrence of multiple primary melanomas is a rare, however possible phenomenon, and it is believed that older, male, white, Atypical Mole Syndrome carriers (sporadic and familial) are part of the possible risk factors for its occurrence. In these patients, it is possible to observe involutional changes or (partial/complete) regression of melanocytic lesions, which are likely to be caused by the generation of a spontaneous immune reaction against specific tumour antigens.

CASE REPORT:

A 58-year-old male patient is presented with two melanocytic lesions located in the right clavicle (subclavicular area) and left the scapular area that meets clinically and dermatoscopically the requirements for malignant melanoma. The lesions were removed by a radical excision with 0.5 cm surgical safety margin in all directions. During the subsequent histological verification it was established it was melanoma with a tumour thickness of 1 mm that in one case, and the other 2 mm. A week later, according to the recommendations of the current guidelines, a re-excision was performed with a surgical safety margin of 1.5 cm in all directions. Considering the complications that are possible during the parallel removal of a draining lymph node recommended for these tumour thicknesses, the patient definitively refused its detection and removal.

CONCLUSION:

A rare case of a Bulgarian patient with multiple primary, however partially involutional melanomas existing for over 20 years, is described. The individual recommendations of dermato-oncologists for the patient (according to AJCC) were not in favour of radicality but of a more sparing, individualised approach, appropriate for that patient. Unfortunately, the approach we used, in this case, was inconsistent with the AJCC or OSMS guidelines. The reason for individualising the approach in the case we have described is due to the variability of the recommendations for surgical treatment of melanomas laid down in the AJCC.

Regression in primary cutaneous melanoma: etiopathogenesis and clinical significance

Though not required currently for staging, regression is a histopathologic parameter typically reported upon diagnosis of an invasive primary cutaneous melanoma. The studies examining the prognostic significance of regression in patient outcome have yielded controversial findings; likely because the definition and assessment of regression have not been consistent, in addition to subjectivity of pathologists' interpretation. Regression is histologically characterized by variable decrease in the number of melanoma cells accompanied by the presence of a host response consisting of dermal fibrosis, inflammatory infiltrate, melanophages, ectatic blood vessels, epidermal attenuation, and/or apoptosis of keratinocytes or melanocytes; the relative extent of these features depends on the stage of the regression. However, the magnitudes to which these individual changes must be present to meet the threshold of histologic regression have not been well defined or agreed upon, and thus, the definition and classification of histologic regression in melanoma varies considerably among institutions and even among individual pathologists. In order to determine the clinical significance of histologic analysis of regression, there is a compelling need for a universal scheme to objectively define and assess histologic regression in primary cutaneous melanoma, so that the biologic and prognostic significance of this process may be completely understood.Laboratory Investigation advance online publication, 27 February 2017; doi:10.1038/labinvest.2017.8.

Regression in thin melanoma is associated with nodal recurrence after a negative sentinel node biopsy

Prognostic markers for nodal metastasis in thin melanoma patients are debated. We present a single institution study looking at factors predictive of nodal disease in thin melanoma patients. Retrospective review from 1997 to 2012 identified 252 patients with thin melanoma (≤1 mm) who underwent a sentinel lymph node biopsy (SLNB). Node‐positive patients included positive SLNB patients and negative SLNB patients who developed a nodal recurrence (false‐negative SLNB). Clinicopathologic characteristics were correlated with nodal status and outcome. Median follow‐up was 45.5 months. Twelve of 252 patients (4.8%) were node‐positive including six positive SLNB (2.4%) and six false‐negative SLNB (2.4%) patients. No clinicopathologic factors were significantly correlated with nodal disease. For the six false‐negative SLNB patients, median time to nodal recurrence was 37.5 months. Regression was seen in only 16% of cases, but the rate increased to 60% for false‐negative SLNB cases. Both age (odds ratio [OR]: 1.09, 95% CI: 1.01–1.17; P = 0.02) and regression (OR: 8.33, 95% CI: 1.34–52.63; P = 0.02) were significantly associated with nodal recurrence after a negative SLNB on univariable analysis. Nodal disease in thin melanoma patients was seen in 4.8% of cases. Although regression was not correlated with nodal metastasis, it was correlated with a false‐negative SLNB. Patients with thin melanoma and regression may need more intensive surveillance after a negative SLNB. Further study is needed to determine if the same immune mechanisms that result in regression in primary tumors also lead to regression in lymph nodes, which may decrease detection of melanoma nodal metastases.

Variations in the expression of TIMP1, TIMP2 and TIMP3 in cutaneous melanoma with regression and their possible function as prognostic predictors

Regression in melanoma is a frequent biological event of uncertain prognostic value as the lesion exhibits heterogeneous phenotypical features, both at the morphological and immunohistochemical level. In the present study, we examined the expression of tissue inhibitors of metalloproteinases (TIMP1, TIMP2 and TIMP3) in melanoma with regression. We specifically examined the expression levels of these TIMPs in regressed components (RC) and non-regressed components (NRC) of the tumor and compared their expression levels with those in non-regressed melanomas. We found that TIMP1 was overexpressed in the NRC of melanomas with partial regression (PR) compared with the NRC in melanomas with segmental regression (SR) (P=0.011). TIMP2 was overexpressed in the NRC of melanomas with PR compared with the NRC in melanomas with SR (PR/SR, P=0.009); or compared with the NRC in melanomas with simultaneous SR-PR (P=0.002); or compared with melanomas without regression (absence of regression) (P=0.037). Moreover, TIMP3 was overexpressed in the NRC of all melanomas with SR as compared to the RC component (P=0.007). Our findings on the differential expression of TIMP1, TIMP2 and TIMP3 in melanomas with regression support the hypothesis that the morphological differences identified in the melanoma regression spectrum may have a correlation with prognosis. This may explain the controversial findings within the literature concerning the biological and prognostic role of regression in melanoma.

Absence of Tumor-Infiltrating Lymphocyte Is a Reproducible Predictive Factor for Sentinel Lymph Node Metastasis: A Multicenter Database Study by the Brazilian Melanoma Group

Aims

The aim of this study is to confirm the function of tumor-infiltrating lymphocytes (TILs) in sentinel lymph node (SLN) metastasis.

Materials and Methods

This retrospective study included 633 patients with invasive melanoma who underwent sentinel lymph node biopsy in 7 referral centers certified by the Brazilian Melanoma Group. Independent risk factors of sentinel node metastasis (SNL) were identified by multiple logistic regression.

Results

SLN metastasis was detected in 101 of 633 cases (16.1%) and in 93 of 428 patients (21.7%) when melanomas ≤ 1mm were excluded. By multiple logistic regression, the absence of TILs was as an independent risk factor of SLN metastasis (OR = 1.8; 95%CI: 1.1–3.0), in addition to Breslow index (greater than 2.00 mm), lymph vascular invasion, and presence of mitosis.

Conclusion

SLNB can identify patients who might benefit from immunotherapy, and the determination of predictors of SLNB positivity can help select the proper population for this type of therapy. The absence of TILs is a reproducible parameter that can predict SLNB positivity in melanoma patients, since this study was made with several centers with different dermatopathologists.

Melanoma: Clinical Presentations

The malignant cell in melanoma is the melanocyte. Because melanocytes are located in the basal layer of the epidermis, melanoma is most commonly seen on the skin. However, melanoma can also arise on mucosal surfaces such as the oral cavity, the upper gastrointestinal mucosa, the genital mucosa, as well as the uveal tract of the eye and leptomeninges. Melanomas tend to be pigmented but can also present as pink or red lesions. They can mimic benign or other malignant skin lesions. This chapter presents the spectrum of typical and less typical presentations of melanoma, as well as patterns of spread. It is divided into (1) cutaneous lesions; (2) patterns of regional spread, (3) non-cutaneous lesions; and (4) distant metastases.

Dermoscopy structures as predictors of sentinel lymph node positivity in cutaneous melanoma

BACKGROUND

Histological features such as Breslow thickness, ulceration and mitosis are the main criteria to guide sentinel lymph node biopsy (SLNB) in melanoma. Dermoscopy may add complementary information to these criteria.

OBJECTIVES

To evaluate the correlation between dermoscopy structures and SLNB positivity.

METHODS

Retrospective analysis of 123 consecutive melanomas with Breslow thickness > 0·75 mm, SLNB performed during follow-up and dermoscopic images.

RESULTS

Men were more likely to have a positive SLNB. The presence of ulceration and blotch and the absence of a pigmented network in dermoscopy correlated with positive SLNB. Histological ulceration also correlated with positive SLNB. A dermoscopy SCORE predicted SLN status with a sensitivity of 96·3% and a specificity of 30·2%. When sex and Breslow thickness were added (SCOREBRESEX), the sensitivity remained at 96·3% but the specificity increased to 52·1%. This study is limited by the number of patients and was performed in only one institution.

CONCLUSIONS

Dermoscopy allowed a more precise prediction of SLN status. If a combined SCOREBRESEX was used to select patients for SLNB, 41·5% of procedures might be avoided.

Melanoma-associated leukoderma - immunology in black and white?

Melanoma is an 'immunogenic tumor', often highly infiltrated with lymphocytes, which are capable of inducing regression of the primary tumor. The commonly observed phenomenon of regression suggests substantial cross-talk between immune cells and transformed melanocytes. An immune response to melanocyte differentiation antigens common to transformed and normal melanocytes manifests clinically at distant sites as melanoma-associated vitiligo or halo nevi. Despite similar antigenic targets, the pathogenesis and prognosis differ between the different melanoma-associated leukodermas. Understanding immunologic cross-talk between melanocytes and the immune system will aid the development of approaches to combat melanoma.

Spontaneous regression of metastatic melanoma - clinical evidence of the abscopal effect

INTRODUCTION

Metastatic melanoma is poorly understood. Regression of primary lesions has been associated with poor prognosis, but spontaneous regression of all metastatic disease is clearly beneficial. A patient's own immune responses occasionally appear to stimulate spontaneous regression of metastatic disease in melanoma.

PATIENTS AND METHODS

We present six interesting cases of complete or nearly complete spontaneous regression of metastatic melanoma, suggest possible causes and review the literature.

RESULTS AND CONCLUSIONS

These cases show clear radiological, pathological or clinical evidence of spontaneous regression of metastatic melanoma. This remains a poorly understood phenomena warranting further investigation and may prove useful in the development of immune mediated solutions.

The synthetic parasite-derived peptide GK1 increases survival in a preclinical mouse melanoma model

PURPOSE

The therapeutic efficacy of a synthetic parasite-derived peptide GK1, an immune response booster, was evaluated in a mouse melanoma model. This melanoma model correlates with human stage IIb melanoma, which is treated with wide surgical excision; a parallel study employing a surgical treatment was carried out as an instructive goal.

EXPERIMENTAL DESIGN

C57BL/6 mice were injected subcutaneously in the flank with 2×10(5) B16-F10 murine melanoma cells. When the tumors reached 20 mm3, mice were separated into two different groups; the GK1 group, treated weekly with peritumoral injections of GK1 (10 μg/100 μL of sterile saline solution) and the control group, treated weekly with an antiseptic peritumoral injection of 100 μL of sterile saline solution without further intervention. All mice were monitored daily for clinical appearance, tumor size, and survival. Surgical treatment was performed in parallel when the tumor size was 20 mm3 (group A), 500 mm3 (group B), and >500 mm3 (group C).

RESULTS

The GK1 peptide effectively increased the mean survival time by 9.05 days, corresponding to an increase of 42.58%, and significantly delayed tumor growth from day 3 to 12 of treatment. In addition, tumor necrosis was significantly increased (p<0.05) in the treated mice. The overall survival rates obtained with surgical treatment at 6 months were 83.33% for group A, 40% for group B, and 0% for group C, with significant differences (p<0.05) among the groups.

CONCLUSIONS

The GK1 peptide demonstrated therapeutic properties in a mouse melanoma model, as treatment resulted in a significant increase in the mean survival time of the treated animals (42.58%). The potential for GK1 to be used as a primary or adjuvant component of chemotherapeutic cocktails for the treatment of experimental and human cancers remains to be determined, and surgical removal remains a challenge for any new experimental treatment of melanoma in mouse models.

Prognosis of patients with transected melanomas

BACKGROUND

The management of melanoma is directly related to Breslow's depth. Biopsying melanomas in a fashion that transects the deep margin precludes an accurate measurement of the true depth.

OBJECTIVE

To examine the prognosis of melanomas transected along the deep margins, as well as cases where no residual melanoma was seen on re-excision after transection.

METHODS

Records from a cohort of patients at one institution were examined from 1996 through 2007. Patients were considered to have "transected" melanomas if tumor cells were present on the deep margin of the biopsy. Overall survival was determined.

RESULTS

Seven hundred fourteen patients were examined. 171 (24%) of all melanomas were transected. 101(59%) of those lacked tumor cells on re-excision. Patients with transected melanomas were older (OR = 1.03, p < .001), and had higher Breslow's depths (OR = 1.21, p < .001) than those without transected tumors. Those with no residual melanoma after transection were younger (OR = 0.98, p = .010) and more likely to have no lymph node involvement (OR = 2.23, p = .037). Neither transection (p = .760), nor lack of residual melanoma on re-excision after transection (p = .793) influenced survival.

CONCLUSION

A high number of melanomas are transected at diagnosis, many of which lack visible tumor. The original Breslow's depth of transected melanomas without residual tumor on re-excision accurately predicts survival and prognosis.

Microvascular lymphatic density analysis in cutaneous regressive and nonregressive superficial spreading melanomas using the lymphatic marker D2-40

BACKGROUND

The prognostic significance of spontaneous regression in melanoma, especially thin lesions, has been a controversial issue for the past 20 years, although recent studies suggest that extensive and late regression may be related to worse prognosis. Many data suggest that lymphangiogenesis predicts metastatic spread in melanoma.

METHODS

We have quantified lymphatic microvascular density (LMVD) in thin (≤ 1.0 mm) superficial spreading melanomas comparing regressive and nonregressive melanomas, regressive and nonregressive areas from the same tumor, and early and late histological stages of regression in the same tumor. In addition, we tried to correlate lymphangiogenesis and tumor growth phase. We conducted histological examinations and immunohistochemical analyses using monoclonal antibody D2-40 with subsequent quantification by image analysis of 37 melanomas, 16 regressive and 21 nonregressive (controls).

RESULTS

We found higher LMVD in the late stage of regression compared with nonregressive area (internal control) of regressive melanomas.

CONCLUSIONS

Our study suggest that the late stage of spontaneous regression in thin melanomas may be related to worse prognosis as it showed higher LMVD, and evidence shows that this is related with increased risk of metastatic spread. But this supposition must be confirmed by a longer follow-up for detection of lymph node metastases.

Prognostic significance of autoimmunity during treatment of melanoma with interferon

Since the pivotal cooperative group trials in the 1980's-90's,, high-dose interferon (HDI) has been the standard of adjuvant therapy. Despite multiple other trials evaluating potential new therapies in melanoma, HDI remains the only FDA-approved therapy for stage IIB and III melanoma. Initial reports from the more recent phase III international trials of modifications of the original HDI regimen linked the appearance of autoimmunity with improved outcomes of disease. Trials of high-dose interleukin-2, many years earlier, reported anecdotal observations that were consistent with the hypothesis that autoimmunity and clinical benefit of immunotherapies of melanoma are linked with one another. The only prospectively conducted study examining the appearance of clinical and laboratory evidence of autoimmunity during HDI therapy was published by Gogas and colleagues, demonstrating statistically significant impact on relapse-free survival and overall survival. Retrospectively conducted studies of different intermediate dosage regimens of interferon (IFN) have not fully confirmed the linkage of serological evidence of autoimmunity and improved survival outcomes. With the emergence of new immunotherapies in treatment of melanoma, this review highlights the importance of autoimmunity for future applications in melanoma and reviews significant differences of past studies evaluating the appearance of autoimmunity during IFN therapy in high-risk melanoma.

High lymphatic vessel density and lymphatic invasion underlie the adverse prognostic effect of radial growth phase regression in melanoma

Regression in the radial growth phase (RGP) of primary cutaneous melanomas is common and has been shown to be an adverse prognostic factor. However, the underlying mechanism is unclear. We performed dual immunohistochemical staining of podoplanin and S-100 on paraffin tissues from 321 patients with vertical growth phase primary melanomas, who had 10 years or more of follow-up. Lymphatic vessel density (LD) and lymphatic invasion (LI) were quantified and documented. The time to first metastasis and melanoma-specific death (MSD) from the date of definite treatment were analyzed using univariate and multivariate Cox models. Among the 116 vertical growth phase melanomas that had regression in the adjacent RGP, 75 (23%) were classified as complete and 41 (13%) were classified as partial. LD was significantly higher (P<0.001) in the 75 lesions with complete regression (mean±SD, 23.7±12.3/mm²) compared with the 41 lesions with partial regression (15.5±7.1/mm²) and was lower in 155 areas of the adjacent normal dermis (7.3±3.5/mm²) and 69 areas of the distant normal dermis (5.5±2.6/mm²). Patients whose lesions had areas of complete regression with LI and either high or low LD or had no LI with high LD, had shorter time to first metastasis (hazard ratio=2.5, 3.8, and 2.5, respectively) and increased risk of melanoma-specific death (hazard ratio=3.1, 1.3 and 3.0, respectively) than those with no LI, and low LD or those without areas of complete regression. These data indicate that complete RGP regression is associated with significantly increased LD. In addition, the adverse prognostic effect of RGP regression is at least partially mediated through lymphangiogenesis and LI in this area.

The pectoralis minor pedicled muscle flap in axillary reconstruction

We report on the case of a patient undergoing resection of a large axillary and chest wall tumor, resulting in exposure of the brachial plexus and axillary vessels. Our experience of the use of the pectoralis minor pedicled flap for the reconstruction of such a defect is described, providing for excellent postoperative mobility of the axilla and minimal donor-site morbidity.

Clinical considerations on sentinel node biopsy in melanoma from an Italian multicentric study on 1,313 patients (SOLISM-IMI)

BACKGROUND

Although widely used for the management of patients with cutaneous melanoma, the sentinel lymph node (SLN) biopsy (SNB) procedure raises several issues. This study was designed to investigate: the predictive factors of SLN status, the false-negative (FN) rate, and patients' prognosis after SNB.

PATIENTS AND METHODS

This is an observational, prospective study conducted on a large series of consecutive patients (n = 1,313) enrolled by 23 Italian centers from 2000 through 2002. A commonly shared protocol was adopted for the SNB surgical procedure and the SLN pathological examination.

RESULTS

The SLN positive and false-negative (FN) rates were 16.9% and 14.4%, respectively (median follow-up, 4.5 years). At multivariable logistic regression analysis, the frequency of positive SLN increased with increasing Breslow thickness (p < 0.0001) and decreased in patients with melanoma regression (p = 0.024). At the multivariable Cox regression analysis, SLN status was the most important prognostic factor (hazards ratio (HR) = 3.08) for overall survival; the other statistically significant factors were sex, age, Breslow thickness, and Clark's level. Considering SLN and NSLN status, including FN cases, we identified four groups of patients with different prognoses. The 5-year overall survival of patients with positive SLNs was 71.3% in those with negative nonsentinel lymph nodes (NSLNs) and 50.4% if NSLNs were positive.

CONCLUSIONS

Regression in the primary melanoma seems to be a protective factor from metastasis in the SLN. When correctly calculated, the SNB FN rate is 15-20%. Furthermore, the SNB is important to more precisely assess the prognosis of patients with melanoma.

[Regression in malignant melanoma. Definition, etiopathogenesis, morphology and differential diagnosis]

Malignant melanoma is a neoplasm that more often tends to undergo regression. Clinically, variation in color is perhaps the most important hallmark of primary cutaneous melanoma. The change in color to white, off-white, blue-white and gray-white is a sign of (spontaneous) regression in malignant melanoma. Histopathologically the process starts with a dense lichenoid infiltrate of lymphocytes, and ends with fibrosis and/or melanosis within a thickened papillary dermis. The dense infiltrate of lymphocytes permeates the thin melanoma and destroys the atypical melanocytes in the epidermis and the papillary dermis. A key concern is how to define regression in a reproducible way. Using the following definition, a statistically significant risk of metastases can be demonstrated in thin melanomas (<1.0 mm) with extensive regression (>50%): "fibroplasia with an absence of epidermal and dermal involvement by melanoma cells, but allowing for (lentiginous) single-cell proliferation of atypical melanocytes along the dermo-epidermal junction".

Leukocyte infiltration and tumor cell plasticity are parameters of aggressiveness in primary cutaneous melanoma

Various clinical and experimental observations detected an immunological host defense in cutaneous melanoma. In order to investigate the prognostic value of leukocyte effector mechanisms, we examined the presence of different subsets of leukocytes in tumor samples of 58 patients diagnosed with primary cutaneous melanoma. The presence of T lymphocytes, cytotoxic T lymphocytes, B lymphocytes, CD16+ cells and macrophages was correlated to Breslow depth. A significantly higher amount of several subsets of leukocytes was found in samples with a more progressed tumor stage and survival analysis demonstrated that a higher amount of T lymphocytes and CD16+ cells was associated with a short survival. The amount of FOXP3+ regulatory T lymphocytes did not correlate with survival, nevertheless, it correlated with the amount of total infiltrate. In contrast, analysis of the expression of CD69, a marker for activated lymphocytes, demonstrated that patients with a higher amount of CD69+ lymphocytes had a better survival. In addition, a new parameter for aggressiveness of melanoma, tumor cell plasticity [i.e., the presence of periodic acid Schiff's (PAS) reagent positive loops], also predicted short survival and a trend of a higher amount of tumor infiltrating leukocytes in tumors with PAS positive loops was observed. These findings demonstrate that leukocyte infiltration and the presence of PAS loops is a sign of tumor aggressiveness and may have prognostic value.

Dermatopathological indicators of poor melanoma prognosis are significantly inversely correlated with the expression of NM23 protein in primary cutaneous melanoma

BACKGROUND

Some dermatopathological parameters are recognized as dominant indicators of high metastatic potential in melanoma, especially Breslow thickness, ulceration, Clark's level of invasion and mitotic rate. Because NM23 protein is the product of a melanoma metastasis suppressor gene, the aim of this study was to compare such dermatopathological indicators of melanoma prognosis with NM23 protein expression in primary cutaneous melanoma.

METHODS

The immunohistochemical NM23 expression was semiquantitatively assessed in 30 primary cutaneous melanomas. Ten dermatopathological parameters were evaluated and compared with NM23 expression.

RESULTS

A significant inverse correlation was found for NM23 expression in comparison with Breslow thickness (p < 0.01), ulceration (p < 0.05), Clark's level (p < 0.01), mitotic rate (p < 0.05), and vertical growth phase (p < 0.05). By contrast, no significant correlation was found for NM23 expression in comparison with cell morphology, presence of adjacent nevus, pigmentation, tumor-infiltrating lymphocytes, and regression was impossible to evaluate.

CONCLUSIONS

The expression of NM23 protein in primary cutaneous melanoma is significantly inversely correlated with dermatopathological parameters currently recognized as powerful indicators of melanoma prognosis. NM23 may be therefore considered in the dermatopathological evaluation of primary cutaneous melanoma.

Metastatic myxoid melanoma with partial regression of the primary lesion

Myxoid melanoma is a rare variant of malignant melanoma. The diagnostic problems are obviously increased when it presents as amelanotic metastasis in a lymph node. An 82-year-old woman presented a subcutaneous mass in the right axilla. A thorough clinical investigation disclosed a pigmented black lesion on the right forearm. The right axillary lymph nodes and the pigmented lesion were resected. In the lymph nodes, proliferation of tumor cells with an abundant mucous substrate was noted. The cells proliferated in a variable pattern, and there were no melanin granules detected on hematoxylin-eosin-stained sections. However, we found melanin granules in the tumor cells observed under electron microscopy. In the pigmented lesion of the right forearm, there were small clusters of tumor cells with melanin granules, suggesting malignant melanoma. In the present case, myxoid metastasis occurred with the partial spontaneous disappearance of the primary nonmyxoid malignant melanoma.

Absence de valeur prédictive des signes de régression histologique sur l’envahissement du ganglion sentinelle

BACKGROUND

The predictive value of regression in melanoma is debated.

AIM OF THE STUDY

A retrospective single-centre study to evaluate the correlation between regression in primary skin tumor and the presence of micrometastases in sentinel lymph nodes.

PATIENTS AND METHODS

Histological signs of regression in 84 melanomas (>1 mm) with corresponding sentinel lymph nodes were studied by two independent pathologists.

RESULTS

Regression was seen in 40 skin melanoma tumors while micrometastasis was seen in 24. Of the tumors with micrometastasis, only 10 were regressive (RR: 0.47, p=0.49). Breslow value>2 mm and male sex were predictive for node micrometastasis (RR: 4.6, p=0.03 and RR: 7.6, p=0.006, respectively). On multivariate analysis, these two factors were independent.

COMMENTS

These data suggest that regression in primary cutaneous melanoma is not predictive for lymph node metastasis.

Unusual findings in papillary thyroid microcarcinoma suggesting partial regression: a study of two cases

Histologic changes of regression have been recognized in many malignant tumors, although they have not been documented in thyroid carcinoma. We analyze here the histologic features of 2 cases of papillary thyroid microcarcinoma, one of the diffuse sclerosing variant and another multicentric of the follicular variant, that suggest partial regression. The histologic and clinical features of the 2 thyroid microcarcinomas were compared with the features of regression reported in other tumors. Hematoxylin and eosin stains were examined in each case. In addition, immunoperoxidase stains for thyroglobulin and thyroid transcription factor-1 were performed on the metastatic and primary lesions of each case. Immunostains for CD4 and CD8 performed on the thyroid lesions were also examined. Both patients presented with metastatic papillary thyroid carcinoma in regional lymph nodes with no clinical or radiologic evidence of primary tumor in the thyroid glands. When examined, the thyroid glands revealed only microscopic foci of papillary thyroid carcinoma measuring less than 1.5 mm, diffuse sclerosis and a lymphocytic infiltrate mainly composed of cytotoxic T lymphocytes around the neoplastic microfollicles. Numerous psammoma bodies were also found in the thyroid of case 1, and venulitis similar to that seen in acute hepatic rejection was also seen in the microcarcinoma of case 2. The 2 patients reported had papillary thyroid microcarcinomas measuring less than 1.5 mm and features suggestive of regression characterized by extensive fibrosis, an accompanying T lymphocyte infiltrate, venulitis, and only a few clusters of neoplastic cells or a few neoplastic follicles. Thus, we believe that these histologic changes suggest regression because papillary thyroid microcarcinomas measuring less than 1.5 mm do not metastasize and have been considered innocuous or medical curiosities.

Detection of tyrosinase mRNA in the sentinel lymph nodes of melanoma patients is not a predictor of short-term disease recurrence

Sentinel lymph node evaluation has enabled identification of patients with cutaneous melanoma who might benefit from elective regional lymph node dissection. Sentinel nodes are currently assessed by histologic and reverse transcription polymerase chain reaction (RT-PCR) evaluation for melanocyte-specific markers. The clinical significance of positive findings by RT-PCR in the absence of histologic evidence of metastasis (HIS(NEG)/PCR(POS)) remains unclear. Examination of 264 lymph nodes from 139 patients revealed histopathologic positivity in 34 patients (24.5%), in which 26 also demonstrated simultaneous RT-PCR positivity (HIS(POS)/PCR(POS)). Of 35 HIS(NEG)/PCR(POS) patients (25.2%), five also had nodal capsular nevi. In total, capsular nevi were detected in 13 patients (9.4%). A total of 70 patients (50.4%) had negative sentinel nodes by both histopathology and RT-PCR (HIS(NEG)/PCR(NEG)). Over a median follow-up of 25 months, local and/or systemic recurrence developed in 31 patients (22.3%). Recurrence rates were similar among patients with histopathologic evidence of sentinel lymph node metastasis, irrespective of RT-PCR status (HIS(POS)/PCR(POS) 62%; HIS(POS)/PCR(NEG) 75%). In contrast, only 10% of HIS(NEG)/PCR(NEG) patients developed recurrence, significantly less than those in either HIS(POS) group (P<0.0001). Recurrence in the HIS(NEG)/PCR(POS)/CN(NEG) group (7.7%) was comparable to that in HIS(NEG)/PCR(NEG) patients and significantly lower than that in either HIS(POS) group (P<0.0001). The only independent prognostic factors identified by multivariate analysis were the Breslow thickness of the primary tumour and histopathologic positivity of sentinel nodes. Our findings support previous observations that histopathologic evidence of metastatic melanoma in sentinel lymph nodes is an independent predictor of disease recurrence. In contrast, detection of tyrosinase mRNA by RT-PCR alone does not appear to increase the likelihood of short-term disease recurrence.

Malignant melanoma in the 21st century, part 2: staging, prognosis, and treatment

Critical to the clinical management of a patient with malignant melanoma is an understanding of its natural history. As with most malignant disorders, prognosis is highly dependent on the clinical stage (extent of tumor burden) at the time of diagnosis. The patient's clinical stage at diagnosis dictates selection of therapy. We review the state of the art in melanoma staging, prognosis, and therapy. Substantial progress has been made in this regard during the past 2 decades. This progress is primarily reflected in the development of sentinel lymph node biopsies as a means of reducing the morbidity associated with regional lymph node dissection, increased understanding of the role of neoangiogenesis in the natural history of melanoma and its potential as a treatment target, and emergence of innovative multimodal therapeutic strategies, resulting in significant objective response rates in a disease commonly believed to be drug resistant. Although much work remains to be done to improve the survival of patients with melanoma, clinically meaningful results seem within reach.

Eleven-year survival from an intra-dermal melanoma

Stage IV metastatic malignant melanoma of unknown primary (TxNxM1a) is known to have a poor prognosis. However, some patients suffering from cutaneous disease originally thought to represent metastasis have fared much better than expected. We report a patient who has survived 11 years following such a diagnosis. Due to the prolonged survival and absence of an identified primary, it is unlikely that the lesion was metastatic but may represent one of a number of other possibilities. A small number of similar cases in the literature suggest a need for awareness of this unusual group of patients.

Completely regressed primary cutaneous malignant melanoma with nodal and/or visceral metastases: a report of 5 cases and assessment of the literature and diagnostic criteria

BACKGROUND

Partial regression of primary cutaneous malignant melanoma is not uncommon and may predict a higher likelihood of metastasis and decreased survival. Complete histologic regression of a primary cutaneous melanoma is a rarer occurrence, with only 34 cases reported in the English-language or English language-summarized literature.

OBSERVATION

We detail 4 cases of complete histologic regression of primary cutaneous melanoma, discovered at presentation with metastatic disease. A pigmented lesion or its remnant, coupled with historical information, was strongly suggestive of cutaneous melanoma. Histologic examination of the lesions, using multiple levels and immunohistochemical stains, failed to reveal residual melanoma. Our cases are typified by the presence of metastasis of melanoma to regional lymph nodes, with the absence of other suspect skin lesions or malignancies. In addition, we present a fifth case involving a completely regressed lesion on the scalp in a patient with cerebral melanoma metastasis and comment on the implications of this case to accepted diagnostic criteria, proposing that consideration of modification to the criteria be entertained.

CONCLUSION

The concept of completely regressed primary cutaneous melanoma is reviewed and the literature critically appraised. When one considers a diagnosis of completely regressed primary cutaneous melanoma, cases must be well documented and biopsy proven. Patients with metastatic melanoma and an occult primary lesion require a thorough skin examination, with serious consideration given to the possibility of completely regressed cutaneous melanoma.

Survival and prognostic variables of cutaneous melanoma observed between 1995 and 2000 at Istituto Dermopatico Dell'Immacolata (IDI-IRCCS), Rome, Italy

INTRODUCTION

Melanoma is an increasingly common malignancy of melanocytes, with incidence rates steadily rising over the past several decades. The objective of this study was to evaluate 5-year survival and to investigate the association between melanoma mortality and clinical and histological features.

METHODS

We conducted a 5-year cohort study among 1020 patients from the same geographic area (Rome) with a single primary cutaneous melanoma diagnosed between January 1995 and December 2000. Survival probability was determined by Kaplan-Meier estimates, and prognostic factors were evaluated by multivariate analysis (Cox proportional hazards model).

RESULTS

Survival decreased with increasing age (P for trend <0.049) and Breslow thickness (P for trend <0.0001). In the multivariate Cox model, Breslow thickness was the only independent prognostic factor for mortality in primary melanoma patients. The risk of death among patients with melanoma increased with increasing tumour thickness 0.76-1.49 mm (relative risk (RR) 2.67, 95% confidence interval (95% CI) 0.63-11.4); 1.50-4.0 mm (RR 6.38, 95% CI 1.75-23.2), >4.0 mm (RR 34.6, 95% CI 8.23-145.7) (P for trend <0.0001). The Years of Life Lost (YLLs) for the Breslow categories < or =0.75 mm, 0.76-1.49 mm, 1.50-4.0 mm and >4.0 mm were 65.4, 153.6, 274.3 and 317.6 years, respectively.

CONCLUSION

This study shows the great importance of secondary melanoma prevention and illustrates how many years of life could be saved by early diagnosis.

Relationship between sentinel lymph node status and regression of primary malignant melanoma

The prognostic significance of spontaneous regression of primary melanoma is a controversial issue. Studies on sentinel lymph node status and circulating tumour cells may represent a step towards a better understanding. The clinical details of 269 melanoma patients who underwent sentinel lymph node biopsy were analysed. Correlation was sought between the parameters of the primary tumour, particularly tumours showing a partial intermediate level of regression, and sentinel lymph node status. The presence of circulating tumour cells was studied by reverse transcription-polymerase chain reaction for tyrosinase messenger RNA preoperatively in 94 patients. Of the examined tumours, 27.8% showed histological features of a partial intermediate level of regression. Regressive tumours were localized predominantly on the trunk (P=0.006), were significantly thinner (P<0.0000) and were less frequently ulcerated (P=0.003) than tumours without regression. Moreover, the majority of regressive melanomas were of the superficial spreading type (P<0.0000) and their sentinel node status was more favourable (P=0.026). We demonstrated the presence of circulating tumour cells in five of 26 (19.2%) regressive and 19 of 68 (29.4%) non-regressive tumours. The difference was not significant (P=0.32). By multivariate analysis, however, the Breslow thickness and ulceration of the primary tumour were predictors of the sentinel lymph node status, in agreement with literature data. A partial intermediate level of regression of the primary tumour did not affect unfavourably the sentinel lymph node status in our study. We failed to demonstrate a significant relationship between the presence of circulating tumour cells and either primary tumour regression or the sentinel lymph node status.