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The immunohistochemical (IHC) marker PReferentially expressed Antigen in MElanoma (PRAME) has shown promise in the diagnosis of melanocytic lesions. A few studies have investigated PRAME IHC expression in acral melanomas, but PRAME expression in subungual melanomas is largely unknown. We evaluated the utility of PRAME IHC expression in distinguishing subungual melanomas (SUM) and non-subungual acral melanomas (AM) from acral nevi (AN).Twenty-two SUM, 20 AM, and 14 AN were identified. IHC studies were performed using an anti-PRAME antibody. The percentage of lesional cells with PRAME expression was recorded and categorized as follows: 0%, 0; 1%-25%, 1+; 26%-50%, 2+; 51%-75%, 3+; and75%, 4+. Patient demographics and other relevant clinicopathologic parameters were recorded.Diffuse (4+) PRAME IHC expression was identified in 55% (12/22) SUM and 70% (14/20) AM, respectively. Any PRAME expression (1+ to 4+) was identified in 73% (16/22) SUMs and 95% (19/20) AM, respectively. One of 14 (7%) AN exhibited PRAME expression; interestingly, the pattern of expression was diffuse.In our study, PRAME IHC expression was useful in identifying AM, including SUM. However, there are exceptions of PRAME-negative melanomas and PRAME-positive nevi.

Supplemental Figure 1. Representative images of nuclear grade. Histopathologic grade was defined according to the nuclear morphology and cytoplasmic evidence of sebaceous differentiation comprising the predominance (>50%) of the tumor cells. (A) High grade tumors exhibited enlarged irregular nuclei with high nuclear:cytoplasmic ratio and only focal evidence of sebaceous differentiation (intracytoplasmic vacuoles indenting the nucleus; H&E, 200x). (B) Intermediate grade tumors exhibited similar enlarged nuclei but with lower nuclear:cytoplasmic ratio and more obvious evidence of sebaceous differentiation (H&E, 200x). (C) Well-differentiated tumors showed only slightly enlarged nuclei and frank evidence of sebaceous differentiation (H&E, 200x).

Supplemental Figure 1. Correlation between dermal mitotic rate and patient survival. Kaplan-Meier estimate of (A) overall survival and (B) disease-specific survival based on dermal mitotic rate (mitotic figures/mm2). Supplemental Figure 2. Derivation of proposed T-category for Primary Vulvar Melanoma. (A, B, C) We first assigned patients with PVM to a T-category according to the AJCC for PCM (7th Edition). (A) Shows the AJCC schema and the number of patients assigned to each category. (B) Kaplan Meier DSS curves for patients stratified by AJCC T-categories demonstrate robust prognostic differences for patients with PVM and pT1 and to an extent pT2 disease from those with pT3 and pT4 disease, but less robust stratification among those patients with PVMs {less than or equal to}2.00 mm; pT1 versus pT2 (isolated in C) or >2.0 mm; pT3 and pT4. (D, E, F) Because both tumor thickness and mitotic rate were independent prognostic factors for DSS and because mitotic rate showed a natural prognostic separation at 2 mitotic figures/mm2 (as shown in Figure 1D), we first asked whether a T-category according to the conventional AJCC cut-offs ({less than or equal to}1.0, 1.01-2.0, 2.01-4.0 and >4.0 mm) subsequently modified by mitotic rate (a: 2.0 mm (pT3 and pT4) had a short DSS independent of mitotic rate. More importantly, among patients with a tumor thickness {less than or equal to}2.0 mm (pT1 or pT2), only those with mitotic rate {greater than or equal to}2/mm2 had a short DSS, which was essentially superimposable with patients with pT3 and pT4 PVM in this schema. (F) Kaplan-Meier survival curve for patients with pT1 and pT2 PVMs show striking differences in survival according to mitotic rate (

Kaplan-Meier estimate of (A) overall survival and (B) disease-specific survival based on dermal mitotic rate (mitotic figures/mm2).

Purpose:In patients with cutaneous melanoma, metastasis in a nonsentinel lymph node (non-SLN) is a strong independent adverse prognostic factor. However, patients with a tumor-involved SLN no longer routinely undergo completion lymph node dissection (CLND). We hypothesized that SLN tumor burden may predict non-SLN tumor burden.Experimental Design:We compared tumor burden parameters between SLN and non-SLN in patients with cutaneous melanoma who underwent SLN biopsy with a positive SLN during 2003 to 2008 at The University of Texas MD Anderson Cancer Center.Results:We identified 336 eligible patients with a positive SLN. Of these, 308 (92%) underwent CLND, and 35 (10%) had non-SLN metastasis. The median follow-up time was 6.0 years. For patients with maximum diameter of tumor in the SLN ≤2.0 mm, >2.0–5.0 mm, and >5.0 mm, non-SLN metastasis was detected in 5 of 200 patients (3%), 10 of 63 patients (16%), and 20 of 57 patients (35%), and the mean maximum diameters of the non-SLN tumor deposits were 0.09, 1.56, and 2.71 mm, respectively (P < 0.0001). The percentage of patients with both subcapsular and intraparenchymal non-SLN tumor was higher for patients with SLN tumor in both locations than for patients with SLN tumor in only one location (P < 0.0001). Extranodal extension in a non-SLN was more common in patients with extranodal extension in an SLN (P = 0.003).Conclusions:In patients with cutaneous melanoma who undergo CLND, SLN tumor burden predicts non-SLN tumor burden. SLN tumor burden parameters provide accurate prognostic stratification independent of non-SLN status and should be considered for incorporation into future staging systems and integrated risk models.

Supplementary Legend

Purpose: Primary vulvar melanoma (PVM) is the second most common vulvar malignancy. Despite their distinct anatomic site and unique molecular–genetic alterations, PVMs are staged according to the American Joint Committee on Cancer (AJCC) guidelines for primary cutaneous melanomas (PCM). However, whether parameters derived for PCM also apply to PVM remain a critical yet largely unexplored clinical question. The objective of this study was to determine the parameters predictive of survival in PVM.Experimental Design: We retrospectively reviewed 100 patients with PVM and determined associations between clinical and histopathologic parameters and disease-specific survival (DSS) and overall survival (OS).Results: Univariate Cox regression analysis demonstrated older age (>56 years), greater tumor thickness, higher dermal mitotic rate, ulceration, lymphovascular invasion, perineural invasion, microscopic satellitosis, and absence of precursor nevus associated with decreased OS. Furthermore, age, midline, and/or multifocal involvement, greater tumor thickness, higher dermal mitotic rate, ulceration, lack of regression, lymphovascular invasion, perineural invasion, and microscopic satellitosis associated with decreased DSS. Multivariate analysis demonstrated tumor thickness, dermal mitotic rate, lymphovascular invasion, microscopic satellitosis, and absence of precursor nevus independently predicted shorter OS. Only tumor thickness and increased dermal mitotic rate (≥2/mm2) independently predicted reduced DSS. In comparison with the AJCC T-category, a novel, bivariate T-category based only on tumor thickness and dermal mitotic rate robustly predicted OS and DSS in our patient cohort.Conclusions: In the largest single institutional study of PVM, we demonstrate a combination of tumor thickness and mitotic rate comprise a simple but robust T-category to direct staging and prognosis. Clin Cancer Res; 23(8); 2093–104. ©2016 AACR.

Supplementary Table 2. Mean per sample coverage information.

Supplementary Table, Materials and References from Activity of dasatinib against L576P KIT mutant melanoma: Molecular, cellular, and clinical correlates

Supplemental Table 3. Summary of TP53 and RB1 mutational status, immunohistochemical detection of TP53 and RB and histopathologic features in primary/locally recurrent ocular adnexal (OA) sebaceous carcinomas.

Table S1A. Relationship between RFS and MSS, and size of tumor deposit in the SLN using the cut-off values of < 0.1 mm, 0.1-1.0 mm, and > 1.0 mm (univariate analysis); Table S1B. Relationship between SLN and non-SLN tumor burden using the cut-off values of < 0.1 mm, 0.1-1.0 mm, and > 1.0 mm (univariate analysis)

Supplementary Table 1. Summary of mutations identified in the entire cohort of primary, locally recurrent and metastatic tumors.

TT, tumor thickness; NR, not reported * Includes vulvar (n=14) and vaginal (n=7) melanomas £ Includes vulvar (n=16), vaginal (n=1) and cervical (n=1) melanomas Â¥ Includes vulvar (n=61), vaginal (n=15), urethral (n=5) and cervical (n=4) melanomas Â,¬ Includes vulvar (n=33) and vaginal (n=11) melanomas Î' Includes vulvar (n=58), vaginal (n=11), cervical (n=7) and other (n=9) melanomas

(A, B, C) We first assigned patients with PVM to a T-category according to the AJCC for PCM (7th Edition). (A) Shows the AJCC schema and the number of patients assigned to each category. (B) Kaplan Meier DSS curves for patients stratified by AJCC T-categories demonstrate robust prognostic differences for patients with PVM and pT1 and to an extent pT2 disease from those with pT3 and pT4 disease, but less robust stratification among those patients with PVMs {less than or equal to}2.00 mm; pT1 versus pT2 (isolated in C) or >2.0 mm; pT3 and pT4. (D, E, F) Because both tumor thickness and mitotic rate were independent prognostic factors for DSS and because mitotic rate showed a natural prognostic separation at 2 mitotic figures/mm2 (as shown in Figure 1D), we first asked whether a T-category according to the conventional AJCC cut-offs ({less than or equal to}1.0, 1.01-2.0, 2.01-4.0 and >4.0 mm) subsequently modified by mitotic rate (a: 2.0 mm (pT3 and pT4) had a short DSS independent of mitotic rate. More importantly, among patients with a tumor thickness {less than or equal to}2.0 mm (pT1 or pT2), only those with mitotic rate {greater than or equal to}2/mm2 had a short DSS, which was essentially superimposable with patients with pT3 and pT4 PVM in this schema. (F) Kaplan-Meier survival curve for patients with pT1 and pT2 PVMs show striking differences in survival according to mitotic rate (

M1a, Metastasis in skin, subcutaneous tissues, or distant lymph nodes; M1b, Metastasis to lung; M1c, Metastasis to all other visceral sites.

Supplemental Table 4. Fisher's exact test to determine associations between the presence of specific mutations and histopathologic phenotypes in ocular adnexal sebaceous carcinomas.

Point mutations in the KIT receptor tyrosine kinase gene have recently been identified in mucosal, acral lentiginous, and chronically sun-damaged melanomas. We have identified the first human melanoma cell line with an endogenous L576P mutation, the most common KIT mutation in melanoma (∼30-40%). In vitro testing showed that the cell viability of the L576P mutant cell line was not reduced by imatinib, nilotinib, or sorafenib small molecule KIT inhibitors effective in nonmelanoma cells with other KIT mutations. However, the viability of the mutant cells was reduced by dasatinib at concentrations as low as 10 nM (P = 0.004). Molecular modeling studies found that the L576P mutation induces structural changes in KIT that reduce the affinity for imatinib (ΔΔGbind = −2.52 kcal/mol) but not for dasatinib (ΔΔGbind = +0.32 kcal/mol). Two metastatic melanoma patients with the L576P KIT mutation were treated with dasatinib, including one patient previously treated with imatinib. Both patients had marked reduction (>50%) and elimination of tumor F18-fluorodeoxyglucose (FDG)-avidity by positron emission tomography (PET) imaging after dasatinib treatment. These data support the selective inhibitory effect of dasatinib against cells harboring the most common KIT mutation in melanoma, and thus has therapeutic implications for acrallentiginous, chronic sun-damaged, and mucosal melanomas. [Mol Cancer Ther 2009;8(8):2079–85]

Purpose:Ocular adnexal (OA) sebaceous carcinoma is an aggressive malignancy of the eyelid and ocular adnexa that frequently recurs and metastasizes, and effective therapies beyond surgical excision are lacking. There remains a critical need to define the molecular-genetic drivers of the disease to understand carcinomagenesis and progression and to devise novel treatment strategies.Experimental Design:We present next-generation sequencing of a targeted panel of cancer-associated genes in 42 and whole transcriptome RNA sequencing from eight OA sebaceous carcinomas from 29 patients.Results:We delineate two potentially distinct molecular-genetic subtypes of OA sebaceous carcinoma. The first is defined by somatic mutations impacting TP53 and/or RB1 [20/29 (70%) patients, including 10 patients whose primary tumors contained coexisting TP53 and RB1 mutations] with frequent concomitant mutations affecting NOTCH genes. These tumors arise in older patients and show frequent local recurrence. The second subtype [9/29 (31%) patients] lacks mutations affecting TP53, RB1, or NOTCH family members, but in 44% (4/9) of these tumors, RNA sequencing and in situ hybridization studies confirm transcriptionally active high-risk human papillomavirus. These tumors arise in younger patients and have not shown local recurrence.Conclusions:Together, our findings establish a potential molecular-genetic framework by which to understand the development and progression of OA sebaceous carcinoma and provide key molecular-genetic insights to direct the design of novel therapeutic interventions.

Context.— Distinction between Merkel cell carcinoma (MCC) and pulmonary small cell carcinoma (PSmCC) can be challenging, even with the aid of immunohistochemistry (IHC) analysis of CK20 and TTF1, as these tumors occasionally lack classic immunophenotypes (CK20+/TTF1− in MCC and CK20−/TTF1+ in PSmCC). Objective.— To evaluate the diagnostic utility of SOX11 and PAX5 IHC for distinguishing MCCs from PSmCCs and compare it with that of CK20 and TTF1 IHC. Design.— SOX11, PAX5, CK20, and TTF1 expression (pattern, intensity, and proportion of tumor cells expressing protein) was assessed in 31 primary and 16 metastatic MCCs and 20 primary and 9 metastatic PSmCCs. Results.— SOX11 expression was present in all MCCs and was predominantly strong and diffuse. Only 19% of primary and 38% of metastatic MCCs exhibited diffuse PAX5 expression; none exhibited strong immunoreactivity. Strong and diffuse SOX11 expression was seen in less than 25% of primary and metastatic PSmCCs. PAX5 expression was rare in PSmCCs and was mostly weak and focal/patchy. SOX11 expression in at least 26% of tumor cells, with at least moderate intensity, favored the diagnosis of MCC over PSmCC (P < .001). Furthermore, SOX11 expression was more likely than CK20 expression to be strong or diffuse in sentinel lymph node (SLN) metastases of MCC, indicating that SOX11 is superior to CK20 for detecting tumor deposits in SLNs in MCC. Conclusions.— Our findings indicate that SOX11 not only is a powerful marker for distinguishing MCCs from PSmCCs, especially when used in conjunction with CK20 and TTF1, but also has utility for screening SLNs in MCC.

Cutaneous lymphoid hyperplasia (CLH) is a benign reactive process with T-cell or B-cell lymphocytic infiltration in the skin, which can simulate cutaneous lymphomas both clinically and histologically. Various antigenic stimuli have been implicated in the development of CLH, including tick bites. Finding histologic evidence of such triggering factors, however, is often difficult. Moreover, the presence of clonality in CLH can potentially be interpreted as a neoplastic process, posing a further diagnostic challenge to dermatopathologists, if one is not aware of such peculiar phenomena. Herein, we describe a case of CLH secondary to a tick bite, featuring both T-cell clonality and monotypic plasma cells with lambda light chain restriction; the diagnostic clue being tick parts, which became evident on assessment of deeper levels. To the best of our knowledge, this is the first reported case of a tick-associated clonal CLH with simultaneous detection of monoclonal T cells and monotypic lambda light chain restriction, mimicking primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder and Borrelia-associated primary cutaneous marginal zone B-cell lymphoma, respectively.

Acral lentiginous melanoma (ALM) is a rare type of cutaneous melanoma with a poor prognosis. It is unclear whether the poor outcome of ALM is due to its inherent disease characteristics or advanced stage at initial diagnosis. To address this question, we retrospectively analyzed the clinicopathologic factors of 828 thin (T1; Breslow thickness ≤1.0 mm) melanomas [129 (15.6%) ALMs and 699 (84.4%) non-ALMs] and their nodal and distance metastases and local recurrence rates and determined their relationship with the disease-specific (DSS), overall (OS), and recurrence-free survivals (RFS) at the pathologic stages T1, T1a, and T1b with a median follow-up time of 84.5 months. With the exception of OS at T1b stage, ALM patients showed significantly lower 5- and 10-year DSS, OS, and RFS rates at every pathologic stage when compared with non-ALM. In multivariable analysis, ALM histologic type, SLN positivity, age, and the use of systemic therapy were detected as independent poor prognostic factors associated with significantly lower survival rates. ALM histologic type was associated with lower DSS and OS rates at T1 and T1a stages and lower RFS rates at T1b stage. SLN positivity was associated with lower DSS, OS, and RFS rates at T1, T1a, and T1b stages. Age was associated with lower OS rates at T1 and T1b stages. Whereas the use of systemic therapy was associated with lower DSS rates at T1a stage and RFS rates at T1b stage. In addition, the ALM group showed significantly older median age patients and higher rates of female sex, Hispanic ethnicity, nevoid cytology, non-brisk tumor-infiltrating lymphocytes, nodal metastasis, and local recurrence at every pathologic stage of thin melanoma. Our findings suggest that ALM is inherently more aggressive than other types of cutaneous melanoma. This information may be useful for prognostic stratification of patients with thin melanomas, especially to help guide the clinical decision-making for SLN biopsy and patients entering clinical trials.

Mycosis fungoides with large cell transformation (MFLCT) can be difficult to distinguish from primary cutaneous CD30+ T cell lymphoproliferative disorders (PC CD30+ LPD), especially primary cutaneous anaplastic large cell lymphoma (PC-ALCL). This diagnostic distinction is critical for appropriate patient management. GATA3 has been proposed to be useful in the discrimination between these two entities. We identified 25 cases of MFLCT and 24 cases of PC CD30+ LPDs (including lymphomatoid papulosis (n=14), PC-ALCL (n=6), and CD30+ LPD, not otherwise specified (n=4)) diagnosed at our institution from 2002 to 2019. Sections from archived specimens were stained to evaluate for GATA3 expression by immunohistochemistry and compared among cutaneous CD30+ T cell LPDs. The majority of the MFLCT cohort had strong, diffuse expression of GATA3 ranging from 0 to 100% of dermal T cells (mean 53.20%) with 15/25 cases (60%) showing GATA3 expression greater than 50%, while the PC CD30+ LPD group showed variable, moderate GATA3 labeling ranging from 0 to 60% of dermal T cells (mean 23.26%), with 5/6 cases (83%) showing GATA3 expression less than 40% (p =0.003). The calculated sensitivity and specificity were 56% and 74%, while positive and negative predictive values were 70% and 61%, respectively. Based on the percent staining of positive cells, using 50% as a cutoff value for expression, GATA3 might be a useful immunohistochemical marker to discriminate MFLCT from PC CD30+ LPDs, including PC-ALCL.

Context.— Accurate diagnosis of melanocytic lesions is fundamental for appropriate clinical management. Objective.— To evaluate the degree of discordance, if any, between histopathologic diagnoses of melanocytic lesions at referring institutions and at a tertiary referral cancer center and the potential impact of such discordance on clinical management. Design.— We retrospectively identified all patients referred to our comprehensive cancer center for evaluation of a melanocytic lesion from January 2010 to January 2011. For each patient, the histopathologic diagnosis from the referring institution was compared with the histopathologic diagnosis from a dermatopathologist at our center. Discordances were classified as major if they resulted in a change in clinical management and minor if they did not. Results.— A total of 1521 cases were included. The concordance rates were 72.2% (52 of 72) for dysplastic nevus, 75.0% (15 of 20) for all other types of nevi, 91.1% (143 of 157) for melanoma in situ, 96.1% (758 of 789) for invasive melanoma, and 99.6% (478 of 480) for metastatic melanoma. Major discordances were found in 20.2% of cases (307 of 1521), and minor discordances were found in 48.8% of cases (742 of 1521). Compared with the guideline-based treatment recommendation based on the referring-institution diagnosis, the guideline-based treatment recommendation based on the cancer center diagnosis was more extensive in 5.9% (89 of 1521) of patients and less extensive in 5.0% (76 of 1521) of patients. Conclusions.— Our findings underscore the importance of secondary histopathologic review of melanocytic lesions by expert dermatopathologists because significant changes in the diagnosis, tumor classification, and/or staging may be identified, thus, resulting in critical changes in recommendations for clinical management.

Cutaneous metastasis may be the initial sign of internal malignancy but more often represents a late manifestation of widely disseminated disease. Breast carcinoma is the most common malignancy to metastasize to the skin. Although several studies have detailed the histopathologic patterns of cutaneous metastasis from internal malignancies, very little has been published regarding metastases of breast carcinoma to the skin. Furthermore, the histopathologic and clinical features observed in the cases of breast carcinoma with local skin involvement as opposed to cases exhibiting distant cutaneous metastases have not been adequately investigated. We have reviewed 232 cases of breast carcinoma with cutaneous metastases from 2 large institutions. All cases of carcinoma of the breast with involvement of the skin of the anterior chest wall were compared with those with distant cutaneous metastases. Two hundred thirty-two cases in 199 patients were included, of which 126 had skin involvement exclusively involving the ipsilateral anterior chest, and 106 had biopsy-proven distant cutaneous metastases. Twelve patients had both local and distal spread. Distant cutaneous metastases showed a predilection for the contralateral anterior chest wall area, followed by the head and neck, back, and abdomen. Histologically, most of the tumors presented in this series showed features of infiltrating ductal carcinoma. In both ipsilateral and distant metastases, the tumors demonstrated little change in histologic features from the primary lesion; however, the distant metastases showed a tendency to display more poorly differentiated features. The mean patient survival when cutaneous involvement was localized to the skin of the anterior chest wall was 23 months as compared with 20.6 months when distant sites were affected. A comparison of the clinicopathologic features of the patients presented in this series suggests that alternate biological mechanisms may apply for local and distant skin metastases from breast carcinoma.

Acral lentiginous melanoma (ALM) is a rare tumor that occurs on non-sun exposed skin areas of the hands and feet. Reports suggest that ALM exhibits poor prognosis, although mechanisms driving this remain poorly understood. Alterations in TERT and the Wnt/β-catenin (Wnt) pathway have been suggested to correlate with prognosis of ALM. Thus, immunohistochemical expression of β-catenin and LEF1 along with TERT amplification by FISH was investigated in 34 primary ALMs, 20 metastatic ALMs, 10 primary non-ALMs, and 15 acral nevi. Foot/toe was the most common primary tumor location (85%) for ALM. TERT amplification was detected in 6 of 28 (21.4%) primary ALM, 2 of 8 (25%) primary non-ALM, and 8 of 18 (44.4%) metastatic ALM, the latter showing significantly higher frequency compared with primary melanomas (P = 0.043). Most metastatic ALMs positive for TERT amplification lacked BRAF V600E (87.5%). Cytoplasmic and nonnuclear expression of β-catenin was variably detected in all cases. Metastatic ALM revealed lower expression of β-catenin compared with primary ALM (P = 0.017). No differences in LEF1 expression were detected among the groups; however, acral nevi showed decreased labeling with dermal descent, in contrast to melanoma. No molecular-genetic alteration correlated with prognosis. TERT amplification by FISH is a frequent finding in primary ALM and appears to increase in metastatic tumors, suggesting a role in tumor progression to metastasis. Although TERT amplification has been reported to be infrequent in primary non-ALM, it showed comparable frequency with ALM in our series. Our immunohistochemical findings are not fully supportive of activation of either canonical or noncanonical Wnt cascades in ALM. TERT amplification by FISH and LEF1 immunohistochemistry may help in the differential diagnosis between primary ALM and acral nevus. TERT amplification appears to be a promising target for therapy in patients with metastatic ALM.

Langerhans cell sarcoma (LCS) is rare and aggressive; patients have an overall survival rate of less than 50%. We present a 62-year-old man with a history of superficial spreading melanoma of the upper back with sentinel lymph node metastasis, Langerhans cell histiocytosis, and LCS. The patient presented with erythematous papules and scaly areas on his face, neck, arms, chest, abdomen, and legs. A skin biopsy revealed a proliferation of large neoplastic cells involving the dermis and with epidermotropism. These cells had atypical bean-shaped nuclei, with ample cytoplasm and abundant mitotic figures including atypical forms. Immunohistochemical studies showed the tumor to be diffusely positive for CD1a, S100 protein, and langerin (CD207) and negative for melanocytic markers. Some tumor cells were positive for cyclin D1. A diagnosis of LCS involving the skin was established. The present study is a very unusual case of LCS showing epidermotropism. The patient's history of metastatic melanoma posed additional challenges for diagnosis, underlying the need of immunophenotyping in these cases. Consensus for optimal standard therapy has not been established in LCS, and thus, early recognition is important since these neoplasms tend to recur and metastasize. LCS in skin is discussed and published cases are comprehensively reviewed.

Pathological staging of primary anorectal mucosal melanoma is often performed according to the American Joint Commission on Cancer (AJCC) guidelines for cutaneous melanoma, as an anorectal melanoma-specific staging system does not exist. However, it remains unknown whether prognostic factors derived for cutaneous melanoma also stratify risk in anorectal melanoma. We retrospectively determined correlations between clinicopathological parameters and disease-specific survival in 160 patients. Patients were grouped by clinical stage at presentation (localized disease, regional or distant metastases). Cox proportional hazards regression models determined associations with disease-specific survival. We also summarized the somatic mutations identified in a subset of tumors analyzed for hotspot mutations in cancer-associated gene panels. Most of the patients were white (82%) and female (61%). The median age was 62 years. With a median follow-up of 1.63 years, median disease-specific survival was 1.75 years, and 121 patients (76%) died of anorectal melanoma. Patients presenting with regional (34%) or distant metastases (24%) had significantly shorter disease-specific survival compared to those with disease localized to the anorectum (42%). Of the 71 anorectal melanoma tumors analyzed for hotspot genetic alterations, somatic mutations involving the KIT gene (24%) were most common followed by NRAS (19%). Increasing primary tumor thickness, lymphovascular invasion, and absence of regression also correlated with shorter disease-specific survival. Primary tumor parameters correlated with shorter disease-specific survival in patients presenting with localized disease (tumor thickness) or regional metastases (tumor thickness, absence of regression, and lymphovascular invasion), but not in patients presenting with distant metastases. Grouping of patients according to a schema based on modifications of the 8th edition AJCC cutaneous melanoma staging system stratified survival in anorectal melanoma. Our findings support stage-specific associations between primary tumor parameters and disease-specific survival in anorectal melanoma. Moreover, the AJCC cutaneous melanoma staging system and minor modifications of it predicted survival among anorectal melanoma patients.

Background: Primary cutaneous melanoma of the breast (PCMB) is a relatively uncommon type of melanoma staged according to the AJCC system for other cutaneous melanomas. However, whether their outcome is different from primary cutaneous melanomas of other sun-exposed sites and the features that predict outcome specifically in PCMB are currently unclear. Moreover, histologically, the breast skin is considered to be a special site for melanocytic lesions. Therefore, we analyzed a retrospective cohort of female PCMB patients to determine the clinical and primary tumor features that correlate with time-to-event outcomes of overall survival (OS) and disease specific survival (DSS). Design: We identified women with PCMB diagnosed and/or treated at our institution between 2002 and 2015. The following data were collected: clinical/ demographic features (age at diagnosis, ethnicity, anatomic site [nipple-areolar complex, upper, lower, medial, lateral]); primary tumor pathologic features (Breslow thickness, Clark level, ulceration, mitotic rate, vertical growth phase (VGP), regression, lymphovascular invasion (LVI), perineural invasion (PNI), tumor infiltrating lymphocytes (TIL) and cytology); and metastatic disease features (satellitosis, date and metastasis to sentinel and/or regional lymph nodes, clinical detectability of nodal metastasis, and date and site of distant metastases). Kaplan Meier methods, univariate and multivariate Cox proportional hazards regression models determined associations with OS and DSS. Results: 82 cases, including 16 in-situ and 66 invasive PCMBs were identified. Most patients were white (98%), with a median age at diagnosis of 40.5 years (range: 15-77). With a median follow up of 7.6 years, the 1, 3, 5, 10-year OS rates were 97.4%, 94.7%, 91.9% and 81.3%, respectively; the 1, 3, 5, 10-year DSS rates were 98.7%, 95.9%, 93.1% and 86.9%, respectively; the median OS and DSS were not reached. Thirteen patients developed metastasis: 5 regional only, 1 distant only and 7 both; of which 6 had metastatic disease at presentation. Eleven patients died, and 8 was due to progression of PCMB. Most of the invasive PCMB were of superficial spreading type (84.8%), with median tumor thickness of 0.47 mm. Univariate analysis of patients with invasive melanoma revealed the following features to be associated with shorter survival (Table 1): age at presentation, Breslow thickness, Clark level, ulceration, mitotic rate and VGP; while histologic type, anatomic site, LVI, PNI, regression, associated nevus, cytology, and TIL were not significant. Adjusting covariate of features significant in univariate analysis, the multivariate analysis demonstrated only Breslow thickness and ulceration to be independently associated with OS and DSS. Conclusion: Primary cutaneous melanomas of the breast often affects white adult women and increasing tumor thickness and ulceration are associated with shorter survival, similar to primary melanomas of other cutaneous sites. Table 1: Clinical and Primary Tumor Features Associated with Overall (OS) and Disease Specific Survival (DSS) in Primary Cutaneous Melanomas of the BreastUnivariate Analysis (p-value)Clinical/ primary tumor featureOSDSSAge at presentation ≥ 41.5 years0.0020.018Breslow Thickness0.0020.001Clark Level0.0040.003Vertical Growth Phase0.0430.038Mitotic Rate0.001 Citation Format: Madhuchhanda Roy, Junsheng Ma, Aysegul A Sahin, Senthilkumar Damodaran, Michael T Tetzlaff, Jonathan L Curry, Ana M Ciurea, Jing Ning, Carlos A Torres-Cabala, Doina Ivan, Phyu P Aung, Merrick I Ross, Jeffrey E Gershenwald, Michael A Davies, Victor G Prieto and Priyadharsini Nagarajan. Primary cutaneous melanoma of the breast in women. A retrospective study of 82 patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-38.

Localized cutaneous argyria is a rare cutaneous disorder that has been associated with occupational exposure, dental procedures, topical agents, acupuncture, earrings, and nasal piercings. In this paper, we review the current literature on localized cutaneous argyria, highlight its clinical and histologic diagnostic features, and then discuss the clinical and histological differential diagnoses for blue-gray skin and black dermal pigment, respectively. We also discuss the utility of ancillary techniques, such as deeper histologic levels, special stains, darkfield microscopy, and advanced micro-analytical techniques in helping diagnose localized cutaneous argyria. Furthermore, we emphasize that a thorough clinical history and astute clinico-pathologic correlation can be the most important diagnostic techniques in correctly diagnosing this rare disorder. Our review aims serve as a reminder to clinicians and pathologists of the importance of including localized cutaneous argyria in the clinical and histological differential diagnosis of pigmented lesions.

The presence of multiple BAP1-negative melanocytic neoplasms is a hallmark of familial cancer susceptibility syndrome caused by germline mutations in BAP1. Melanocytic tumors lacking BAP1 expression may also present as sporadic lesions in patients lacking a germline BAP1 mutation. Here, we report histomorphologic and clinical characteristics of cutaneous melanomas with loss of BAP1 expression in 4 patients with no known history of BAP1-associated cancer susceptibility syndrome. The lesions were nodular melanomas composed predominantly of intradermal large epithelioid (Spitzoid) melanocytes with nuclear pseudoinclusions as well as scattered multinucleated cells, arising in association with a typical intradermal nevus. Of the 4 patients, only 1 had recurrence. This patient had multiple recurrences with in-transit and regional lymph node metastases. To the best of our knowledge, this is the first reported series of cutaneous melanomas with loss of BAP1 expression arising in patients without a family history of cancer.

Purpose: Ocular adnexal (OA) sebaceous carcinoma is an aggressive malignancy of the eyelid and ocular adnexa that frequently recurs and metastasizes, and effective therapies beyond surgical excision are lacking. There remains a critical need to define the molecular-genetic drivers of the disease to understand carcinomagenesis and progression and to devise novel treatment strategies. Experimental Design: We present next-generation sequencing of a targeted panel of cancer-associated genes in 42 and whole transcriptome RNA sequencing from eight OA sebaceous carcinomas from 29 patients. Results: We delineate two potentially distinct molecular-genetic subtypes of OA sebaceous carcinoma. The first is defined by somatic mutations impacting TP53 and/or RB1 [20/29 (70%) patients, including 10 patients whose primary tumors contained coexisting TP53 and RB1 mutations] with frequent concomitant mutations affecting NOTCH genes. These tumors arise in older patients and show frequent local recurrence. The second subtype [9/29 (31%) patients] lacks mutations affecting TP53, RB1, or NOTCH family members, but in 44% (4/9) of these tumors, RNA sequencing and in situ hybridization studies confirm transcriptionally active high-risk human papillomavirus. These tumors arise in younger patients and have not shown local recurrence. Conclusions: Together, our findings establish a potential molecular-genetic framework by which to understand the development and progression of OA sebaceous carcinoma and provide key molecular-genetic insights to direct the design of novel therapeutic interventions.

Melanomas, like nonmelanoma skin cancers, are known to be causally related to sun exposure. It is therefore not surprising to see benign nevi and melanomas in a background of solar damage, which at times may complicate their distinction. Because of their long-standing nature, nevi often occur before the development of solar elastosis and as such are intimately associated with the solar elastosis. In contrast, visible solar elastosis often occurs before the development of melanoma, in which case the band of solar elastosis is displaced downward from the overlying invasive melanoma and/or its host response. We describe 4 cases in which invasive melanoma cells were intimately admixed with actinically damaged elastin fibers in the absence of a prominent host response. In each case, melanoma cells were admixed with prominent solar elastosis and lacked a significant host response, suggesting that they were either histiocytes or an associated melanocytic nevus. Recognition of this potential pitfall may be helpful in the diagnosis of primary/in-transit/satellite/metastatic melanoma as well as when evaluating marginal status and determining Breslow thickness.

Post-radiation vascular lesions are a rare complication most commonly seen in patients previously treated for breast cancer. The main two entities include angiosarcoma (AS), which are malignant tumors that have a poor prognosis, and atypical vascular lesions (AVL), which typically behave in a benign manner and only rarely progress to angiosarcoma. The overall incidence of these lesions is low, but it appears to be increasing. Histopathologic distinction of AVL and AS is essential due to different clinical outcomes and treatment. However, due to the occasional existence of overlapping clinical and histopathologic features, it may be sometimes difficult to render a definite diagnosis, particularly in small biopsies. Ancillary techniques are, in general, of little help for separating the borderland cases but, in some instances, immunohistochemical study (IHC) for Ki67 and IHC or fluorescence in situ hybridization analysis for MYC may help in the diagnosis of angiosarcoma. Herein we discuss the clinical characteristics, histopathologic features, management strategies, and outcome of these lesions, with special emphasis on their differential diagnosis.

Mycosis fungoides with large cell transformation (MFLCT) can be difficult to distinguish from primary cutaneous CD30+ T cell lymphoproliferative disorders (PC CD30+ LPD), especially primary cutaneous anaplastic large cell lymphoma (PC-ALCL). This diagnostic distinction is critical for appropriate patient management. GATA3 has been proposed to be useful in the discrimination between these two entities. We identified 25 cases of MFLCT and 24 cases of PC CD30+ LPDs (including lymphomatoid papulosis (n=14), PC-ALCL (n=6), and CD30+ LPD, not otherwise specified (n=4)) diagnosed at our institution from 2002 to 2019. Sections from archived specimens were stained to evaluate for GATA3 expression by immunohistochemistry and compared among cutaneous CD30+ T cell LPDs. The majority of the MFLCT cohort had strong, diffuse expression of GATA3 ranging from 0 to 100% of dermal T cells (mean 53.20%) with 15/25 cases (60%) showing GATA3 expression greater than 50%, while the PC CD30+ LPD group showed variable, moderate GATA3 labeling ranging from 0 to 60% of dermal T cells (mean 23.26%), with 5/6 cases (83%) showing GATA3 expression less than 40% (p =0.003). The calculated sensitivity and specificity were 56% and 74%, while positive and negative predictive values were 70% and 61%, respectively. Based on the percent staining of positive cells, using 50% as a cutoff value for expression, GATA3 might be a useful immunohistochemical marker to discriminate MFLCT from PC CD30+ LPDs, including PC-ALCL.

Cutaneous involvement in multiple myeloma (MM) is a rare manifestation, being more prevalent in patients with aggressive subtypes, and refractory to standard therapies. Due to the rarity of this diagnosis, the reported clinical characteristics have been protean and relatively non-specific. Lower extremity involvement of cutaneous MM is an uncommon anatomical location for this diagnosis. We present a patient with refractory IgG lambda MM, and a past medical history of squamous cell carcinoma of the lower extremities who developed cutaneous MM in his lower leg. At the time of initial evaluation, the lesions mimicked squamous cell carcinoma, posing a diagnostic challenge. Histopathological and immunohistochemical studies confirmed cutaneous involvement by multiple myeloma. There needs to be a high clinical suspicion for cutaneous MM in patients with MM presenting with new skin lesions.

Context.— Acral lentiginous melanoma is a rare and aggressive type of cutaneous melanoma that arises on the acral skin and the nail unit. The prognostic significance of subungual anatomic site in acral lentiginous melanoma is not established. Objective.— To assess the impact of subungual anatomic site on overall survival and disease-specific survival in acral lentiginous melanoma. Design.— Retrospective cohort analysis. Clinicopathologic characteristics of 627 primary acral lentiginous melanomas (45 [7%] subungual and 582 [93%] nonsubungual) were summarized, and the impact of these characteristics on overall survival and disease-specific survival was determined using univariate and multivariable analyses. Results.— No significant differences in clinicopathologic features were identified between the subungual and nonsubungual acral lentiginous melanomas. The 1-, 5-, and 10-year overall survival rates were 81%, 40%, and 28%, respectively, for subungual acral lentiginous melanoma and 94%, 59%, and 38%, respectively, for nonsubungual acral lentiginous melanoma (P = .04); risk of death was significantly higher for subungual tumors (hazard ratio [95% confidence interval] = 1.59 [1.02–2.50]; P = .04). The 1-, 5-, and 10-year disease-specific survival rates were 94%, 56%, and 48%, respectively, for subungual acral lentiginous melanoma versus 96%, 69%, and 55%, respectively, for nonsubungual acral lentiginous melanoma (P = .18). By multivariable analysis, independent poor prognostic factors included older age and ulceration for overall survival and greater Breslow thickness and sentinel lymph node positivity for overall survival and disease-specific survival. Subungual anatomic site was not an independent prognostic factor for overall or disease-specific survival. Conclusions.— Subungual anatomic site is not an independent prognostic factor for acral lentiginous melanoma.

Context.— Molecularly distinct from cutaneous melanomas arising from sun-exposed sites, acral lentiginous melanomas (ALMs) typically lack ultraviolet-signature mutations, such as telomerase reverse transcriptase (TERT) promoter mutations. Instead, ALMs show a high degree of copy number alterations, often with multiple amplifications of TERT, which are associated with adverse prognosis. The prognostic value of TERT protein expression in acral melanomas, however, is not established. Objective.— To evaluate the frequency and pattern of TERT immunoreactivity and assess the potential utility of TERT expression as a prognostic indicator in ALMs. Design.— TERT expression by immunohistochemistry was analyzed in a series of 57 acral and nonacral melanocytic lesions, including 24 primary and 6 metastatic ALMs. Clinical outcome in patients with ALMs by TERT expression was assessed. Results.— TERT expression was more frequent in ALMs than in nonlentiginous acral melanomas and nonacral cutaneous melanomas, and was absent in acral nevi (P = .01). When present, TERT expression in ALMs was cytoplasmic and more intense than TERT expression in other melanocytic lesions (P = .05) with a higher H-score (P = .01). There was a trend toward decreased overall survival in patients with ALMs with TERT immunoreactivity, but it did not reach statistical significance. Furthermore, no correlation was found between TERT expression and disease-specific survival in patients with ALMs. Conclusions.— Although TERT protein expression was frequently detected in both primary and metastatic ALMs, TERT immunoreactivity in ALMs did not correlate with survival in our study. Further studies with larger cohorts are needed to elucidate the prognostic value of TERT expression in ALMs.

Cutaneous carcinosarcomas are rare biphenotypic tumors that simultaneously show epithelial and mesenchymal differentiation. The most common carcinomatous components in skin carcinosarcomas are basal cell carcinoma and squamous cell carcinoma; adnexal carcinomas are rarely encountered. We report a case of an adnexal carcinoma with ductal and squamous differentiation and spindle cell component, interpreted as carcinosarcoma. Loss of immunohistochemical expression of E-cadherin and β -catenin detected in the sarcomatous component suggested epithelial mesenchymal transition (EMT). RNA sequencing analysis identified several gene mutations and alterations such as translocations and upregulations/downregulations, either shared by the two components of the tumor or differentially present in the carcinoma or the sarcoma parts. Thus, mutations in genes, such as TP53, were found in both components of the tumor while mutations in PDGFRA and RB1 (a pathogenic missense mutation) were exclusively present in the sarcomatous areas, further supporting EMT. EMT is a dynamic process by which tumors acquire mesenchymal phenotype while simultaneously losing epithelial properties. Although the pathways involved in EMT have been extensively studied, this phenomenon still needs to be investigated in cutaneous tumors of adnexal origin for a better understanding of their pathogenesis. These molecular changes may represent promising targets for personalized therapies. This article is protected by copyright. All rights reserved.

Acral lentiginous melanoma (ALM) is a rare type of cutaneous melanoma with a poor prognosis. It is unclear whether the poor outcome of ALM is due to its inherent disease characteristics or advanced stage at initial diagnosis. To address this question, we retrospectively analyzed the clinicopathologic factors of 828 thin (T1; Breslow thickness ≤1.0 mm) melanomas [129 (15.6%) ALMs and 699 (84.4%) non-ALMs] and their nodal and distance metastases and local recurrence rates and determined their relationship with the disease-specific (DSS), overall (OS), and recurrence-free survivals (RFS) at the pathologic stages T1, T1a, and T1b with a median follow-up time of 84.5 months. With the exception of OS at T1b stage, ALM patients showed significantly lower 5- and 10-year DSS, OS, and RFS rates at every pathologic stage when compared with non-ALM. In multivariable analysis, ALM histologic type, SLN positivity, age, and the use of systemic therapy were detected as independent poor prognostic factors associated with significantly lower survival rates. ALM histologic type was associated with lower DSS and OS rates at T1 and T1a stages and lower RFS rates at T1b stage. SLN positivity was associated with lower DSS, OS, and RFS rates at T1, T1a, and T1b stages. Age was associated with lower OS rates at T1 and T1b stages. Whereas the use of systemic therapy was associated with lower DSS rates at T1a stage and RFS rates at T1b stage. In addition, the ALM group showed significantly older median age patients and higher rates of female sex, Hispanic ethnicity, nevoid cytology, non-brisk tumor-infiltrating lymphocytes, nodal metastasis, and local recurrence at every pathologic stage of thin melanoma. Our findings suggest that ALM is inherently more aggressive than other types of cutaneous melanoma. This information may be useful for prognostic stratification of patients with thin melanomas, especially to help guide the clinical decision-making for SLN biopsy and patients entering clinical trials.

The family of blue nevi includes the common blue nevus (BN), cellular blue nevus (CBN), and atypical BN, while melanomas with BN-like morphology can either arise in association with a blue nevus (MABN) or in the de novo setting mimicking cellular blue nevus (MMCBN). Recent molecular and immunohistochemical studies have demonstrated loss of BAP-1 in MABN/MMCBN but not in BN/CBN, suggesting that loss of BAP-1 correlates with a malignant phenotype in these lesions. In this study, we applied anti-BAP-1 antibodies to a series of CBN/BN (n = 11) and MABN/MMCBN (n = 4). Nuclear BAP-1 expression was detected in the majority of CBN/BN (n = 10/11) but was lost in 1 case. Most cases of MABN/MMCBN showed loss of nuclear BAP-1 expression (n = 3/4), with one case of MMCBN showing preserved BAP-1 expression. Demonstration of BAP-1 loss in a single case of CBN and preservation of BAP-1 expression in 1 case of MMCBN may indicate that detection of alterations in BAP-1 protein expression by immunohistochemistry may not be a completely reliable biomarker for the distinction of BN/CBN from MABN/MMCBN. Further investigation of the significance of BAP-1 loss/preservation in BN-like tumors is warranted.

Acral lentiginous melanoma (ALM) is a rare tumor that occurs on non-sun exposed skin areas of the hands and feet. Reports suggest that ALM exhibits poor prognosis, although mechanisms driving this remain poorly understood. Alterations in TERT and the Wnt/β-catenin (Wnt) pathway have been suggested to correlate with prognosis of ALM. Thus, immunohistochemical expression of β-catenin and LEF1 along with TERT amplification by FISH was investigated in 34 primary ALMs, 20 metastatic ALMs, 10 primary non-ALMs, and 15 acral nevi. Foot/toe was the most common primary tumor location (85%) for ALM. TERT amplification was detected in 6 of 28 (21.4%) primary ALM, 2 of 8 (25%) primary non-ALM, and 8 of 18 (44.4%) metastatic ALM, the latter showing significantly higher frequency compared with primary melanomas (P = 0.043). Most metastatic ALMs positive for TERT amplification lacked BRAF V600E (87.5%). Cytoplasmic and nonnuclear expression of β-catenin was variably detected in all cases. Metastatic ALM revealed lower expression of β-catenin compared with primary ALM (P = 0.017). No differences in LEF1 expression were detected among the groups; however, acral nevi showed decreased labeling with dermal descent, in contrast to melanoma. No molecular-genetic alteration correlated with prognosis. TERT amplification by FISH is a frequent finding in primary ALM and appears to increase in metastatic tumors, suggesting a role in tumor progression to metastasis. Although TERT amplification has been reported to be infrequent in primary non-ALM, it showed comparable frequency with ALM in our series. Our immunohistochemical findings are not fully supportive of activation of either canonical or noncanonical Wnt cascades in ALM. TERT amplification by FISH and LEF1 immunohistochemistry may help in the differential diagnosis between primary ALM and acral nevus. TERT amplification appears to be a promising target for therapy in patients with metastatic ALM.