Wnt/beta-catenin activated non pilomatrical carcinoma of the skin: a case series.

Among skin epithelial tumors, recurrent mutations in the APC/CTNNB1 genes resulting in activation of the Wnt/ß-catenin pathway have been reported predominantly in neoplasms with matrical differentiation. In the present study, we describe the morphologic, immunohistochemical, and genetic features of 16 primary cutaneous carcinomas harboring mutations activating the Wnt/ß-catenin pathway without evidence of matrical differentiation, as well as four combined tumors in which a similar Wnt/ß-catenin activated carcinoma component was associated with Merkel cell carcinoma or pilomatrical carcinoma. Among the pure tumor cases, 6/16 patients were female with a median age of 80 years (range: 58-98). Tumors were located on the head and neck (n=7, 44%), upper limb (n=4, 25%), trunk (n=3, 18%), and leg (n=2, 13%). Metastatic spread was observed in 4 cases resulting in death from disease in one patient. Microscopically, all cases were poorly differentiated neoplasms infiltrating the dermis and/or subcutaneous tissue. In 13 cases, solid "squamoid" areas were associated with a basophilic component characterized by rosette/pseudoglandular formation resulting in a biphasic appearance. Three specimens consisted only of poorly differentiated carcinoma lacking rosette formation. Immunohistochemical studies showed frequent expression of EMA (100%), BerEP4 (100%), cytokeratin 7 (94%), chromogranin A (44%), synaptophysin (82%) and cytokeratin 20 (69%). Complete loss of Rb expression was observed in all but one case. Nuclear ß-catenin and CDX2 expressions were detected in all cases. Recurrent pathogenic somatic mutations were observed in APC (60%), CTNNB1 (40%) and RB1 (n=47%). Global methylation analysis confirmed that cases with rosette formation constituted a homogenous tumor group distinct from established skin tumor entities (pilomatrical carcinoma, Merkel cell carcinoma and squamous cell carcinoma) while the 3 other cases lacking such morphologic features did not. In addition, we identified four combined neoplasms in which there was a component showing a similar poorly differentiated rosette forming carcinoma demonstrating Rb loss and beta-catenin activation associated with either Merkel cell carcinoma (n=3) or pilomatrical carcinoma (n=1). In conclusion, we describe a distinctive neoplasm, for which we propose the term "Wnt/ß-catenin activated rosette-forming carcinoma", morphologically characterized by the association of rosette formation, squamous and/or neuroendocrine differentiation, diffuse CDX2 expression, Rb loss, and mutations in CTNNB1/APC genes.

Distinctive genomic features of human T-lymphotropic virus type 1-related adult T-cell leukemia-lymphoma in Western populations.

Adult T-cell leukemia-lymphoma (ATLL) is an aggressive Human T-cell Leukemia Virus Type 1 (HTLV-1)-driven malignancy. Although Western hemisphere (Afro-Caribbean and South American) patients face worse prognoses, our understanding of ATLL molecular drivers derives mostly from Japanese studies. We performed multi-omic analyses to elucidate the genomic landscape of ATLL in Western cohorts. Recurrent deletion and/or damaging mutations involving FOXO3, ANKRD11, DGKZ, and PTPN6 implicate these genes as potential tumor suppressors. RNA-seq, published functional data and in vitro assays support the roles of ANKRD11 and FOXO3 as regulators of T-cell proliferation and apoptosis in ATLL, respectively. Survival data suggest ANKRD11 mutation may confer a worse prognosis. Japanese and Western cohorts, in addition to acute and lymphomatous subtypes, demonstrated distinct molecular patterns. GATA3 deletion was associated with unfavorable chronic cases. IRF4 and CARD11 mutations frequently emerged in relapses after interferon therapy. Our findings reveal novel putative ATLL driver genes and clinically relevant differences between Japanese and Western ATLL patients.

Real-life efficacy of immunotherapy for Sézary syndrome: a multicenter observational cohort study.

Background: Sézary syndrome is an extremely rare and fatal cutaneous T-cell lymphoma (CTCL). Mogamulizumab, an anti-CCR4 monoclonal antibody, has recently been associated with increased progression-free survival in a randomized clinical trial in CTCL. We aimed to evaluate OS and prognostic factors in Sézary syndrome, including treatment with mogamulizumab, in a real-life setting. Methods: Data from patients with Sézary (ISCL/EORTC stage IV) and pre-Sézary (stage IIIB) syndrome diagnosed from 2000 to 2020 were obtained from 24 centers in Europe. Age, disease stage, plasma lactate dehydrogenases levels, blood eosinophilia at diagnosis, large-cell transformation and treatment received were analyzed in a multivariable Cox proportional hazard ratio model. This study has been registered in ClinicalTrials (SURPASSe01 study: NCT05206045). Findings: Three hundred and thirty-nine patients were included (58% men, median age at diagnosis of 70 years, Q1-Q3, 61-79): 33 pre-Sézary (9.7% of 339), 296 Sézary syndrome (87.3%), of whom 10 (2.9%) had large-cell transformation. One hundred and ten patients received mogamulizumab. Median follow-up was 58 months (95% confidence interval [CI], 53-68). OS was 46.5% (95% CI, 40.6%-53.3%) at 5 years. Multivariable analysis showed that age ≥ 80 versus <50 (HR: 4.9, 95% CI, 2.1-11.2, p = 0.001), and large-cell transformation (HR: 2.8, 95% CI, 1.6-5.1, p = 0.001) were independent and significant factors associated with reduced OS. Mogamulizumab treatment was significantly associated with decreased mortality (HR: 0.34, 95% CI, 0.15-0.80, p = 0.013). Interpretation: Treatment with mogamulizumab was significantly and independently associated with decreased mortality in Sézary syndrome. Funding: French Society of Dermatology, Swiss National Science Foundation (IZLIZ3_200253/1) and SKINTEGRITY.CH collaborative research program.

Citrullinated Histone H3, a Marker for Neutrophil Extracellular Traps, Is Associated with Poor Prognosis in Cutaneous Squamous Cell Carcinoma Developing in Patients with Recessive Dystrophic Epidermolysis Bullosa.

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare severe hereditary skin disease characterized by skin and mucosa fragility, resulting in blister formation. The most severe complication in RDEB patients is the development of cutaneous squamous cell carcinoma (SCC), leading to premature death. There is a great deal of evidence suggesting a permissive tumor microenvironment (TME) as a driver of SCC development in RDEB patients. In a cohort of RDEB patients, we characterized the immune profiles of RDEB-SCCs and compared them with clinical, histopathological, and prognostic features. RDEB-SCCs were subdivided into four groups based on their occurrence (first onset or recurrences) and grading according to clinical, histopathological parameters of aggressiveness. Thirty-eight SCCs from 20 RDEB patients were analyzed. Five RDEB patients experienced an unfavorable course after the diagnosis of the first SCC, with early recurrence or metastasis, whereas 15 patients developed multiple SCCs without metastasis. High-risk primary RDEB-SCCs showed a higher neutrophil-to-lymphocyte ratio in the tumor microenvironment and an increased proportion of neutrophil extracellular traps (NETs). Additionally, citrullinated histone H3, a marker of NETs, was increased in the serum of RDEB patients with high-risk primary SCC, suggesting that this modified form of histone H3 may serve as a potential blood marker of unfavorable prognosis in RDEB-SCCs.

Hidrocystoma-like tumours with RET or ALK fusion: a study of four cases.

Hidrocystoma is thought to be a benign retention cyst of sweat ductal units. The lesion is usually located in the periorbital skin; however, lesions with similar histopathological features are rarely observed in extra-facial sites. Herein, we present four cases of hidrocystoma-like tumours in extra-facial skin sites that harboured a RET or ALK rearrangement. This study features a 67-year-old female with a 10 mm-sized digital tumour (Case 1), a 62-year-old male with an 8 mm-sized clavicular tumour (Case 2), a 61-year-old male with a 19 mm-sized digital tumour (Case 3), and an 11-year-old female with a 10 mm-size lower leg tumour (Case 4) as well as five control cases (Cases 5-9) of classical periorbital hidrocystoma. In Cases 1-4, multicystic tumours comprising a two-cell layer of inner cuboidal ductoglandular (p63- and SOX10+/-) and outer flat myoepithelial (p63+ and SOX10+) cells were observed. The inner ductoglandular tumour cells exhibited micropapillary projections and Roman bridging structures. No apparent atypical cells were observed. NCOA4::RET in Cases 1 and 3, CCDC6::RET in Case 2, and SLC12A2::ALK in Case 4 were revealed by next-generation sequencing or Sanger sequencing. In contrast, control cases of classical hidrocystoma (Cases 5-9) did not show intracystic proliferation, abundant cytoplasm, ALK immunoreactivity, or NCOA4::RET detection in the tumour cells. RET/ALK-rearranged hidrocystoma-like tumours are tumour entities that can be distinguished from classical hidrocystoma. This RET/ALK-rearranged neoplasm is benign and is frequently observed in the digits. Future studies will establish the concept, detailed clinicopathological characteristics, and genetic variations of hidrocystoma-like tumours.

Radiotherapy and prognostic factors in adnexal carcinomas: A retrospective study of 657 patients from the French CARADERM network.

BACKGROUND: Cutaneous adnexal carcinomas are a heterogeneous group of rare neoplasms. Surgical excision is the first-line treatment in localized stage. The use and effectiveness of radiotherapy have not been thoroughly evaluated in these neoplasms. OBJECTIVES: The present work analyses prognostic factors on outcomes in skin adnexal carcinomas, based on data from the CARADERM (CAncers RAres DERMatologiques) database. METHODS: Data were collected retrospectively including demographic data, tumour types and therapeutic characteristics of all patients included in the CARADERM database, with at least one informative follow-up visit. Analyses were performed on three populations: patients with complete resection of the primary tumour (ADJ/primary population), patients achieving complete remission after complete resection of a recurrent tumour (ADJ/recurrent population) and patients with unresectable locally advanced or metastatic tumours (ADV/MET population). Overall and recurrence/progression-free survivals at 3-year were analysed using Cox regression models. RESULTS: Radiotherapy did not affect overall survival (OS) in the ADJ/primary population. Adjusted recurrence-free survival (RFS) was significantly lower in the radiotherapy group in ADJ/primary group. Older patients had significantly poorer OS and RFS. Tumour size and immunosuppression were significantly associated with poorer RFS only. Radiotherapy had no effect on OS and RFS in the ADJ/recurrent population. Age was the only factor associated with a poorer OS. Radiotherapy was significantly associated with longer progression-free survival (PFS) in age-sex adjusted analysis in the ADV/MET population, without effect on OS. CONCLUSIONS: Our study shows that age, tumour size and immunosuppression are significantly associated with survival in localized adnexal carcinomas. Radiotherapy may improve PFS in the ADV/MET population but not in localized and recurrent carcinomas after complete excision.

[Cutaneous adnexal tumours: Development and synthesis of diagnostic fusion genes]. / Tumeurs annexielles cutanées : mise au point et synthèse des gènes de fusion à connaître pour le diagnostic.

Cutaneous adnexal tumours are a heterogeneous group of epithelial lesions that includes tumours with follicular, sudoral and/or sebaceous differentiation, or even several combined lines of differentiation. Over the last few years, molecular analysis of these lesions has allowed to identify specific molecular events responsible for tumour development in an increasing number of tumour types. Like other rare neoplasms, such as soft tissue tumours, adnexal tumours display fusion genes resulting from chromosomal translocations that may be specific for the diagnosis if molecular data are properly integrated in the clinical and morphological setting. Molecular testing of adnexal tumours is valuable as it allows to strengthen the robustness of the diagnosis for a group of tumours displaying a wide morphological spectrum. It has allowed to refine the diagnostic criteria and to develop increasingly specific diagnostic immunostainings. Finally, molecular testing has been responsible for the identification of new entities or morphological subtypes of previously known entities. The aim of this review is to provide an update on cutaneous adnexal tumours associated with fusion genes and to evaluate the impact of molecular data on the diagnosis of these lesions.

Pathophysiology of cutaneous T-cell lymphomas: Perspective from a French referral centre.

Cutaneous T-cell lymphomas (CTCL) are a diverse group of malignant blood disorders characterized by initial skin infiltration, and sometimes, tumor spreading to lymph nodes, blood, and viscera. Mycosis fungoides is the most common form. Sézary syndrome is a distinctive form of CTCL marked by a significant presence of circulating tumor cells in peripheral blood. These diseases are characterized by the plasticity and heterogeneity of the tumor cells in the different tissue compartments, and a difficulty in identifying these tumor cells for diagnostic purposes and therapeutic monitoring. Progress has been made in the understanding of the pathophysiology of these diseases in recent years, and we provide here a review of these advancements.

Porocarcinomas with PAK1/2/3 fusions: a series of 12 cases.

AIMS: Porocarcinoma is a malignant sweat gland tumour differentiated toward the upper part of the sweat duct and may arise from the transformation of a preexisting benign poroma. In 2019, Sekine et al. demonstrated the presence of YAP1::MAML2 and YAP1::NUTM1 fusions in most poromas and porocarcinomas. Recently, our group identified PAK2-fusions in a subset of benign poromas. Herein we report a series of 12 porocarcinoma cases harbouring PAK1/2/3 fusions. METHODS AND RESULTS: Five patients were male and the median age was 79 years (ranges: 59-95). Tumours were located on the trunk (n = 7), on the thigh (n = 3), neck (n = 1), or groin area (n = 1). Four patients developed distant metastases. Microscopically, seven cases harboured a benign poroma component and a malignant invasive part. Ductal formations were observed in all, while infundibular/horn cysts and cells with vacuolated cytoplasm were detected in seven and six tumours, respectively. In three cases, the invasive component consisted of a proliferation of elongated cells, some of which formed pseudovascular spaces, whereas the others harboured a predominant solid or trabecular growth pattern. Immunohistochemical staining for CEA and EMA confirmed the presence of ducts. Focal androgen receptor expression was detected in three specimens. Whole RNA sequencing evidenced LAMTOR1::PAK1 (n = 2), ZDHHC5::PAK1 (n = 2), DLG1::PAK2, CTDSP1::PAK1, CTNND1::PAK1, SSR1::PAK3, CTNNA1::PAK2, RNF13::PAK2, ROBO1::PAK2, and CD47::PAK2. Activating mutation of HRAS (G13V, n = 3, G13R, n = 1, Q61L, n = 2) was present in six cases. CONCLUSION: Our study suggests that PAK1/2/3 fusions is the oncogenic driver of a subset of porocarcinomas lacking YAP1 rearrangement.

Inactivation of kindlin-3 increases human melanoma aggressiveness through the collagen-activated tyrosine kinase receptor DDR1.

The role of the focal adhesion protein kindlin-3 as a tumor suppressor and its interaction mechanisms with extracellular matrix constitute a major field of investigation to better decipher tumor progression. Besides the well-described role of kindlin-3 in integrin activation, evidence regarding modulatory functions between melanoma cells and tumor microenvironment are lacking and data are needed to understand mechanisms driven by kindlin-3 inactivation. Here, we show that kindlin-3 inactivation through knockdown or somatic mutations increases BRAFV600mut melanoma cells oncogenic properties via collagen-related signaling by decreasing cell adhesion and enhancing proliferation and migration in vitro, and by promoting tumor growth in mice. Mechanistic analysis reveals that kindlin-3 interacts with the collagen-activated tyrosine kinase receptor DDR1 (Discoidin domain receptor 1) modulating its expression and its interaction with ß1-integrin. Kindlin-3 knockdown or mutational inactivation disrupt DDR1/ß1-integrin complex in vitro and in vivo and its loss improves the anti-proliferative effect of DDR1 inhibition. In agreement, kindlin-3 downregulation is associated with DDR1 over-expression in situ and linked to worse melanoma prognosis. Our study reveals a unique mechanism of action of kindlin-3 in the regulation of tumorigenesis mediated by the collagen-activated tyrosine kinase receptor DDR1 thus paving the way for innovative therapeutic targeting approaches in melanoma.

CD39 is expressed by a wide range of cutaneous T-cell lymphomas.

CD39, an ectoenzyme in the immunosuppressive CD39/CD73/adenosine pathway, known to promote solid tumour outgrowth and spreading, was investigated in both skin and blood compartments of cutaneous T cell lymphomas. CD39 was overexpressed by peripheral blood T-cells in Sezary syndrome and mycosis fungoides, and in skin-infiltrating lymphocytes of Sezary syndrome, mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma and primary cutaneous CD30-positive lymphoproliferation. Our study emphasizes the interest in using CD39/CD73/adenosine pathway blocking agents for cutaneous T cell lymphomas treatment.

PROM2 overexpression induces metastatic potential through epithelial-to-mesenchymal transition and ferroptosis resistance in human cancers.

INTRODUCTION: Despite considerable therapeutic advances in the last 20 years, metastatic cancers remain a major cause of death. We previously identified prominin-2 (PROM2) as a biomarker predictive of distant metastases and decreased survival, thus providing a promising bio-target. In this translational study, we set out to decipher the biological roles of PROM2 during the metastatic process and resistance to cell death, in particular for metastatic melanoma. METHODS AND RESULTS: Methods and results: We demonstrated that PROM2 overexpression was closely linked to an increased metastatic potential through the increase of epithelial-to-mesenchymal transition (EMT) marker expression and ferroptosis resistance. This was also found in renal cell carcinoma and triple negative breast cancer patient-derived xenograft models. Using an oligonucleotide anti-sense anti-PROM2, we efficaciously decreased PROM2 expression and prevented metastases in melanoma xenografts. We also demonstrated that PROM2 was implicated in an aggravation loop, contributing to increase the metastatic burden both in murine metastatic models and in patients with metastatic melanoma. The metastatic burden is closely linked to PROM2 expression through the expression of EMT markers and ferroptosis cell death resistance in a deterioration loop. CONCLUSION: Our results open the way for further studies using PROM2 as a bio-target in resort situations in human metastatic melanoma and also in other cancer types.

From Histiocytoid Sweet Syndrome to Myelodysplasia Cutis: History and Perspectives.

In 2005, a new histologic variant of Sweet syndrome (SS) has been described and termed histiocytoid SS (HSS). Clinically, patients had a typical SS, but on skin biopsy, the infiltrates were composed of immature nonblast myeloid cells. Nearly 50% of patients with HSS have myelodysplastic syndrome (MDS). HSS may be the first manifestation leading to the diagnosis of MDS. In 2015, a new category of myeloid dermatosis has been proposed, called myelodysplasia cutis, describing the specific skin infiltration by myelodysplastic cells in patients with MDS.