The Histopathology of Vacuoles, E1 Enzyme, X-Linked, Autoinflammatory, Somatic Syndrome: Report of 12 Skin Biopsies From 6 Patients.

ABSTRACT: We present the histopathology of 12 skin biopsies from 6 patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome and review the literature. The age of these 6 men ranges from 62 to 83 years (median of 70 years). UBA1 mutation was documented in all 6 patients. Multiple organ systems were involved with constitutional symptoms noted in 4 of 6 patients (67%), cutaneous involvement in 6 of 6 patients (100%), hematologic abnormalities in 6 of 6 patients (100%), pulmonary involvement in 4 of 6 patients (67%), musculoskeletal abnormalities in 3 of 6 patients (50%), vascular thrombosis in 2 of 6 patients (33%), ocular involvement in 2 of 6 patients (33%), and gastrointestinal involvement in 5 of 6 patients (83%). Of the 6 presented patients, neutrophilic dermatosis was seen in 3 biopsies, histiocytoid neutrophilic dermatosis in 1 biopsy, neutrophilic dermatosis with vasculitis in 1 biopsy, neutrophilic and granulomatous dermatitis in 2 biopsies, septal panniculitis consistent with erythema nodosum in 2 biopsies, and nonspecific patterns in 3 biopsies. In summary, neutrophilic dermatosis, small-vessel vasculitis, and panniculitis are frequent histopathologic patterns noted in decreasing frequency in skin biopsies of the patients with vacuoles, enzyme E1, X-linked, autoinflammatory, somatic syndrome. However, the histopathologic findings can be diverse, nonspecific in some instances, and varied among different biopsies obtained from the same patient.

High-resolution RNA-sequencing reveals TRIM33::CSDE1 gene fusion in metastasizing vulvar melanoma.

Although mucosal melanomas are rare and constitute approximately 1.4% of all melanomas, the prognosis of patients with mucosal melanoma is poorer in comparison to cutaneous melanomas. Despite their poor prognosis, limited treatment options are currently available for patients with advanced disease. These noncutaneous subtypes of melanomas are not responding to treatment used for cutaneous melanomas. We performed RNA sequencing on four mucosal melanoma samples comprising of two primary tumors and two corresponding metastases. A TRIM33::CSDE1 fusion was detected in both the primary tumor and metastasis of a vulvar melanoma, supporting the fusion to be a driver in oncogenesis. Vulvar melanoma is the third tumor to have been reported to harbor TRIM33::CSDE1 fusion. Detecting fusions may have a clinically significant impact in patients with advanced mucosal melanoma who have failed front-line immunotherapy.

Malignant Proliferating Pilar Tumor With Sarcomatous Transformation ("Carcinosarcoma"): Case Report With Molecular Profile.

ABSTRACT: Malignant proliferating pilar tumors (MPPTs) are rare, unique cutaneous adnexal tumors. Sarcomatous transformation in MPPTs is even rarer (4 previous cases reported). Here, we report an extraordinary case of a MPPT with sarcomatous transformation occurring on the scalp of a 63-year-old man with an in-depth molecular profile along with histologic, immunohistochemical, and follow-up data. Shared mutations in the epithelial and sarcomatous components included a loss-of-function TP53 mutation. An inactivating TP53 mutation was only identified in the epithelial component, and an inactivating CDKN2A mutation was only identified in the sarcomatous component. Copy number variations previously reported in MPPT were also identified, including 6p21.1 loss, 6q arm loss, and 15q21.1-q26.3 gain [epithelial], and 6p22.2-p22.3 loss [sarcoma]. Histologically, the tumor demonstrated juxtaposed areas of proliferating pilar tumor, carcinoma with clear cell change, and sarcomatous areas that did not stain for AE1/AE3, p40, CD34, S100 protein, and smooth muscle actin  by immunohistochemistry. The patient is alive at 2 years without evidence of recurrence or metastasis.

Co-Targeting of DTYMK and PARP1 as a Potential Therapeutic Approach in Uveal Melanoma.

Uveal melanoma (UM) is the most common primary intraocular tumor in adults, with no standardized treatment for advanced disease. Based on preliminary bioinformatical analyses DTYMK and PARP1 were selected as potential therapeutic targets. High levels of both proteins were detected in uveal melanoma cells and correlated with increased tumor growth and poor prognosis. In vitro tests on MP41 (BAP1 positive) and MP46 (BAP1 negative) cancer cell lines using inhibitors pamiparib (PARP1) and Ymu1 (DTYMK) demonstrated significant cytotoxic effects. Combined treatment had synergistic effects in MP41 and additive in MP46 cell lines, reducing cell proliferation and inhibiting the mTOR signaling pathway. Furthermore, the applied inhibitors in combination decreased cell motility and migration speed, especially for BAP1-negative cell lines. Our hypothesis of the double hit into tumoral DNA metabolism as a possible therapeutic option in uveal melanoma was confirmed since combined targeting of DTYMK and PARP1 affected all tested cytophysiological parameters with the highest efficiency. Our in vitro findings provide insights into novel therapeutic avenues for managing uveal melanoma, warranting further exploration in preclinical and clinical settings.

Clinicopathological and Molecular Features of Penile Melanoma With a Proposed Staging System.

Penile melanomas (PM) are an exceedingly rare subtype of mucosal melanoma (MM), and we reviewed the clinicopathologic features and molecular profile in 8 PMs. The patient ages ranged from 46 to 78 (mean: 62.8) years with involvement on the glans (n=5; 62.5%), penile urethra (n=2; 25%), and foreskin (n=1, 12.5%). Tumor depth ranged from 1.6 to 10.0 (mean: 5.25) mm. Most of the patients underwent partial penectomy (n=6; 75%) and sentinel lymph node (LN) biopsy N=7; 87.5%). Seven patients had metastatic disease at diagnosis, 6 involving LNs and 1 the adrenal gland, and 4 died of disease with a mean follow-up period of 40.5 (2 to 95) months. Five of 7 (71%) cases identified 15 molecular alterations within KIT , CDKN2A , NF1 , PTEN , and APC (n=2 each), and NRAS , MAP3K1 , CDH1 , MSH6 , and TERT (n=1 each). Two cases were not found to harbor genetic aberrations, and 1 case failed testing. In addition, we reviewed the English literature and included 93 cases with a reported depth of invasion and follow-up. A total of 101 PMs were analyzed for prognostic parameters, and the overall survival was significantly worse in patients with LN metastasis (P=0.0008), distant metastasis (P=0.0016), and greater depth of invasion (P=0.0222) based upon T-stage. While T4 conferred substantially worse survival, the delineation of the survival curves between T2 and T3 was less clear, and combining T2+T3 disease had a strong prognostic impact ( P =0.0024). Prognostic parameters used in the staging of cutaneous melanomas may also be used in PMs. An alternative staging system expanding the inclusion criteria for T2 might provide a more accurate prognostic stratification.

Cutaneous Intravascular Hematolymphoid Entities: A Review.

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Utilizing PTEN immunohistochemistry as a screening test for Cowden syndrome.

OBJECTIVES: Cowden syndrome (CS) is a multisystem disease with an elevated lifetime risk of internal malignancy. We aim to assess the role of PTEN immunostain as a screening test for CS in a variety of common CS-associated neoplasms, with a particular focus on cutaneous tumors. METHODS: We retrospectively searched for patients meeting criteria for CS and/or demonstrating germline PTEN mutation from 2008 to 2022. We then performed PTEN immunostains on tumors of these patients as well as control cases. RESULTS: Our study included 30 patients with CS who had a total of 25 CS-associated malignancies (13 thyroid, 8 breast, and 4 endometrial carcinomas). Specifically, there were 11 patients with biopsy-confirmed CS-associated cutaneous neoplasms, including 1 patient with multiple trichilemmomas and 3 with multiple sclerotic fibromas. In total, 45 CS-associated tumors (6 trichilemmomas, 7 sclerotic fibromas, 5 thyroid carcinomas, 18 adenomatous thyroid nodules, 6 breast carcinomas, and 3 endometrial carcinomas) and 31 non-CS cases (9 trichilemmomas, 5 sclerotic fibromas, 8 adenomatous thyroid nodules, and 3 thyroid, 3 breast, and 3 endometrial carcinomas) were available for PTEN immunohistochemical staining. PTEN expression was lost in 43 (96%) of 45 CS-associated lesions and retained in 30 (97%) of 31 sporadic tumors. The overall sensitivity and specificity of PTEN loss of expression as a screening test for CS were 96% and 97%, respectively. CONCLUSIONS: PTEN immunohistochemistry on CS-associated tumors, especially trichilemmomas, can serve as a readily accessible and cost-effective screening test for CS.

SATB2, CKAE1/AE3, and synaptophysin as a sensitive immunohistochemical panel for the detection of lymph node metastases of Merkel cell carcinoma.

Histopathological evaluation of lymph nodes in Merkel cell carcinoma has become crucial in progression estimation and treatment modification. This study was undertaken to determine the most sensitive immunohistochemical panel for detecting MCC nodal metastases. We included 56 patients with 102 metastatic MCC lymph nodes, which were tested with seven antibodies: cytokeratin (CKAE1/AE3), CK20, chromogranin A, synaptophysin, INSM1, SATB2, and neurofilament (NF). Tissue microarrays (TMA) composed of 2-mm tissue cores from each nodal metastasis were constructed. A semiquantitative 5-tier scoring system (0%, < 25%, 25-74%, 75-99%, 100% positive MCC cells with moderate to strong reactivity) was implemented. In the statistical assessment, we included Merkel cell polyomavirus (MCPyV) status and expression heterogeneity between lymph nodes from one patient. A cumulative percentage of moderate to strong expression ≥ 75% of tumoral cells was observed for single cell markers as follows: 91/102 (89.2%) SATB2, 85/102 (83%) CKAE1/AE3, 80/102 (78.4%) synaptophysin, 75/102 (75.5%) INSM1, 68/102 (66.7%) chromogranin A, 60/102 cases (58.8%) CK20, and 0/102 (0%) NF. Three markers presented a complete lack of immunoreactivity: 8/102 (7.8%) CK20, 7/102 (6.9%) chromogranin A, and 6/102 (5.9%) NF. All markers showed expression heterogeneity in lymph nodes from one patient; however, the most homogenous was INSM1. The probability of detecting nodal MCC metastases was the highest while using SATB2 as a first-line marker (89.2%) with subsequential adding CKAE1/AE3 (99%); these results were independent of MCPyV status. Synaptophysin showed a superior significance in confirming the neuroendocrine origin of metastatic cells. This comprehensive analysis allows us to recommend simultaneous evaluation of SATB2, CKAE1/AE3, and synaptophysin in the routine pathologic MCC lymph node protocol.

Combinations of EGFR and MET inhibitors reduce proliferation and invasiveness of mucosal melanoma cells.

Mucosal melanoma (MM) is a very rare and aggressive type of cancer for which immunotherapy or targeted therapy such as BRAF/MEK inhibitors, used in cutaneous melanoma, usually fail. Due to our earlier experience showing the high effectiveness of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (MET) inhibitors in reducing the activation of the MAPK and PI3K/AKT signalling pathways, we aim to test whether these drugs would also be effective for mucosal melanoma. Cells representing two commercially available mucosal melanoma cell lines (GAK and HMVII) and one cell line obtained from a patient's vaginal melanoma were treated with MET or EGFR inhibitors, or combinations of these agents. The dual-inhibitor treatment strategy resulted in a decrease of cell proliferation, migration and invasion. Moreover, combinations of inhibitors led to reduction of pEGFR/EGFR and pMET/MET ratio and downregulation of PI3K/AKT and MEK/ERK1/2-based signalling pathways. Our findings indicate a potential therapeutic strategy based on EGFR and MET inhibitors in mucosal melanoma, which should be further evaluated in vivo and in clinical experiments. They also suggest that targeting multiple receptor tyrosine kinases may block signalling crosstalk and possibly delay the appearance of resistance to kinase inhibitors in mucosal melanoma cells.

Ki67 is a better marker than PRAME in risk stratification of BAP1-positive and BAP1-loss uveal melanomas.

BACKGROUND: Accurate risk stratification of uveal melanoma (UM) patients is important for determining the interval and frequency of surveillance. Loss of BAP1 expression has been shown to be strongly associated with UM-related death and metastasis. METHODS: In this study of 164 enucleated UMs, we assessed the prognostic role of preferentially expressed antigen in melanoma (PRAME) expression and Ki67 proliferation index measured by digital quantitation using QuPath programme in patients with BAP1-positive and BAP1-loss UMs. RESULTS: In univariate analyses with log-rank tests and Kaplan-Meier curves, PRAME further stratified only overall survival (OS) in BAP1-positive and BAP1-loss tumour groups. However, Ki67 further stratified both OS and disease-free survival (DFS) in BAP1-positive and BAP1-loss tumour groups. In multivariate analyses, Ki67 percentage and BAP1 were independent survival predictors for both OS and DFS, whereas PRAME was not a significant covariate. In model comparisons, combined Ki67 and BAP1 performed better than combined PRAME and BAP1 in risk-stratifying patients for both OS and DFS. Ki67 was better than PRAME in risk stratification of BAP1-positive UMs. Low Ki67 index correlated with significantly prolonged DFS in BAP1-loss UMs. CONCLUSION: A panel of Ki67 and BAP1 could be a helpful risk stratification strategy for UM.

Histologic margin status is a predictor of relapse in lentigo maligna melanoma.

BACKGROUND: Most surgical margins for lentigo maligna melanomas reported in the literature are clinical and not histologic. OBJECTIVES: We sought to determine whether histologic margin status is an independent predictor of progression. METHODS: Clinicopathologic information of 268 invasive lentigo maligna melanomas diagnosed from 1990-2019 were analyzed. Statistical analyses were performed using Cox proportional hazards model and Boruta method. RESULTS: A total of 75% of the lesions were located on the head and neck. The range of follow-up for all patients was 0 to 31.8 years (median, 10.2 years). Time to local recurrence ranges from 0 to 20 years (median, 3 years). Progression developed in 54 (20.1%) of 268 patients. Local recurrence was seen only in 36 (13.4%), both local recurrence and subsequent metastasis in 7 (2.6%), and only metastasis in 11 (4.1%) of 268 patients. Histologic margin status (positive and close/<3 mm) and tumor site (head and neck location) significantly correlated with worse progression-free survival. LIMITATIONS: Single institution and retrospective study. CONCLUSIONS: Histologic margin status is the strongest predictor of progression for lentigo maligna melanoma. Patients with positive or close/<3 mm histologic margins should consider a re-excision due to the increased risk of relapse.

Malignant Proliferating Pilar Tumor: Clinicopathologic, Immunohistochemical, and Molecular Study of 17 Cases.

Proliferating pilar tumors are rare neoplasms that differentiate toward the outer sheath near the isthmus and can rarely undergo malignant transformation. We performed histopathologic evaluation on 26 benign proliferating pilar tumor (BPPT) and 17 malignant proliferating pilar tumor (MPPT). Ki-67 and p53 immunostains were performed on 13 BPPT and 10 MPPT. Six MPPT cases were successfully analyzed by a next-generation sequencing platform which surveyed exonic DNA sequences of 447 cancer genes and 191 regions across 60 genes for rearrangement detection. Patient demographics and clinical characteristics were similar between the BPPT and MPPT groups. Follow-up data of 16 of 17 MPPT (median, 25 mo) showed metastasis in 1 MPPT. The histologic features associated with MPPT include size >2.5 cm, adjacent desmoplastic stroma, small nests or cords of atypical epithelium in surrounding stroma, irregular infiltration or borders, abnormal keratinization, large hyperchromatic nuclei, prominent nucleoli, severe cytologic atypia, nuclear pleomorphism, necrosis, and increased mitotic figures. MPPT harbors copy number gains of 15q and losses of 6p and 6q, findings previously reported in BPPT. However, MPPT harbors frequent TP53 mutations as molecular markers of progression. Different from cutaneous squamous cell carcinoma, MPPT more frequently demonstrates low tumor mutational burden and typically lacks a UV signature, suggestive of a different etiologic pathway than squamous cell carcinoma. In summary, with a median follow-up of 25 months, this study shows that MPPT is a biologically indolent carcinoma with rare metastasis. Molecular analyses suggest a non-UV-related pathogenesis with frequent TP53 aberration.

SOX10.

The SOX gene encodes for transcription factors that are involved in embryogenesis and cell differentiation. Specifically, SOX10 aids with neural crest shuttling and development. In diagnostic histopathology, Sox10 immunostain is a helpful ancillary test due to its high sensitivity for melanocytic and peripheral nerve sheath neoplasms, and its role in distinguishing triple-negative breast carcinomas from gynaecological carcinoma, cutaneous adnexal neoplasms and salivary glands neoplasms from histological mimics.

Prognostic biomarkers for survival in mucosal melanoma.

Mucosal melanoma (MM) is a rare subtype of melanoma with an aggressive clinical course. In cutaneous melanoma (CM), the absence of pigmentation and presence of NRAS/KRAS mutations are biomarkers indicating an aggressive clinical course with shorter overall survival. Similar data for MM are missing. We present the real-world outcome data in a cohort of genotyped MM patients and assessed the prognostic relevance of pigmentation- and NRAS/KRAS mutation status. We correlated pathological reports and clinical data with overall survival of patients with MM. Furthermore, we performed clinically integrated molecular genotyping and analyzed real world treatment regimens for covariates associated with clinical outcome. We identified 39 patients with available clinical and molecular data. Patients with amelanotic MM had a significantly shorter overall survival (p = .003). In addition, the presence of a NRAS or KRAS mutation was significantly associated with poor overall survival (NRAS or KRAS p = .024). Currently, it is unknown if the same prognostic relevance for the lack of pigmentation and RAS mutations in CM, exists in MM. Here we analyzed a cohort of MM for outcome measures and determined that two known prognostic biomarkers for CM are in fact novel prognosticators for MM.

Expression of Genes Associated With Epithelial-Mesenchymal Transition in Merkel Cell Polyomavirus-Negative Merkel Cell Carcinoma.

Two accepted possible pathways for Merkel cell carcinoma (MCC) pathogenesis include the clonal integration of the Merkel cell polyomavirus (MCPyV) into the neoplastic cells and by UV irradiation. We hypothesize that, in UV etiology, the expression of genes associated with epithelial-mesenchymal transition (EMT) would be higher in MCPyV-negative MCCs. We compared RNA expression in 16 MCPyV-negative with that in 14 MCPyV-positive MCCs in 30 patients using NanoString panel of 760 gene targets as an exploratory method. Subsequently, we confirmed the findings with a publicly available RNA sequencing data set. The NanoString method showed that 29 of 760 genes exhibited significant deregulation. Ten genes (CD44, COL6A3, COL11A1, CXCL8, INHBA, MMP1, NID2, SPP1, THBS1, and THY1) were part of the EMT pathway. The expression of CDH1/E-cadherin, a key EMT gene, and TWIST1, regulator gene of EMT, was higher in MCPyV-negative tumors. To further investigate the expression of EMT genes in MCPyV-negative MCCs, we analyzed publicly available RNA sequencing data of 111 primary MCCs. Differential expression and gene set enrichment analysis of 35 MCPyV-negative versus 76 MCPyV-positive MCCs demonstrated significantly higher expression of EMT-related genes and associated pathways such as Notch signaling, TGF-ß signaling, and Hedgehog signaling, and UV response pathway in MCPyV-negative MCCs. The significance of the EMT pathway in MCPyV-negative MCCs was confirmed independently by a coexpression module analysis. One of the modules (M3) was specifically activated in MCPyV-negative MCCs and showed significant enrichment for genes involved in EMT. A network analysis of module M3 revealed that CDH1/E-cadherin was among the most connected genes (hubs). E-cadherin and LEF1 immunostains demonstrated significantly more frequent expression in MCPvV-negative versus MCPyV-positive tumors (P < .0001). In summary, our study showed that the expression of EMT-associated genes is higher in MCPyV-negative MCC. Because EMT-related proteins can be targeted, the identification of EMT pathways in MCPyV-negative MCCs is of potential therapeutic relevance.

Clinical Next-Generation Sequencing Panels Reveal Molecular Differences Between Merkel Cell Polyomavirus-Negative Merkel Cell Carcinomas and Neuroendocrine Carcinomas.

OBJECTIVES: We aim to determine molecular differences between Merkel cell polyomavirus (MCPyV)-negative Merkel cell carcinomas (MCCs) and neuroendocrine carcinomas (NECs). METHODS: Our study included 56 MCCs (28 MCPyV negative, 28 MCPyV positive) and 106 NECs (66 small cell NECs, 21 large cell NECs, and 19 poorly differentiated NECs) submitted for clinical molecular testing. RESULTS: APC, MAP3K1, NF1, PIK3CA, RB1, ROS1, and TSC1 mutations, in addition to high tumor mutational burden and UV signature, were frequently noted in MCPyV-negative MCC in comparison to small cell NEC and all NECs analyzed, while KRAS mutations were more frequently noted in large cell NEC and all NECs analyzed. Although not sensitive, the presence of either NF1 or PIK3CA is specific for MCPyV-negative MCC. The frequencies of KEAP1, STK11, and KRAS alterations were significantly higher in large cell NEC. Fusions were detected in 6.25% (6/96) of NECs yet in none of 45 analyzed MCCs. CONCLUSIONS: High tumor mutational burden and UV signature, as well as the presence of NF1 and PIK3CA mutations, are supportive of MCPyV-negative MCC, whereas KEAP1, STK11, and KRAS mutations are supportive of NEC in the appropriate clinical context. Although rare, the presence of a gene fusion is supportive of NEC.

Molecular profiling of primary uveal melanoma: results of a Polish cohort.

There is no published data regarding the molecular alterations of Polish patients with primary uveal melanoma. We performed whole exome sequencing of 20 primary uveal melanomas (UMs), 10 metastasizing and 10 non-metastasizing cases to identify significant molecular alterations. We detected mutations and copy number variants in the BAP1 gene in 50% (10 cases) of the cases. GNA11 mutations were detected in 50% (10 cases) including nine p.Q209L and one p.R183C. GNAQ mutations gene were detected in 40% (8 cases) and all were p.Q209P. SF3B1, EIF1AX, PLCB4 , and PALB2 mutations were detected in one case each. Genetic aberrations of FBXW7 were detected in 55% of cases, with copy number loss of 10 and missense mutation in one. Gain or loss of copy number was observed in 60%, 60%, and 10% of cases in MYC, MLH1 , and CDKN2A genes, respectively. BAP1 and GNAQ tumor suppressor genes are more often mutated in UM with metastasis, while GNA11 mutations are more frequently detected in non-metastasizing tumors. MYC copy gain was present twice as frequently (80% versus 40%) in cases with versus those without metastases. BAP1 mutation correlated with worse overall survival; while GNA11 mutation and CDKN2A loss correlated with better and worse progression-free survival, respectively. We have confirmed BAP1 prognostic potential and documented frequent MYC amplification in metastasizing cases. Although GNA11 mutation and CDKN2A loss significantly correlated with progression-free survival in our study, our sample size is small. The prognostic significance of GNAQ/GNA11 mutation and CDKN2A loss would require further investigation.