Clonal expansion of intra-epithelial T cells in breast cancer revealed by spatial transcriptomics.

The spatial distribution of tumor-infiltrating lymphocytes (TIL) predicts breast cancer outcome and response to systemic therapy, highlighting the importance of an intact tissue structure for characterizing tumors. Here, we present ST-FFPE, a spatial transcriptomics method for the analysis of formalin-fixed paraffin-embedded samples, which opens the possibility of interrogating archival tissue. The method involves extraction, exome capture and sequencing of RNA from different tumor compartments microdissected by laser-capture, and can be used to study the cellular composition of tumor microenvironment. Focusing on triple-negative breast cancer (TNBC), we characterized T cells, B cells, dendritic cells, fibroblasts and endothelial cells in both stromal and intra-epithelial compartments. We found a highly variable spatial distribution of immune cell subsets among tumors. This analysis revealed that the immune repertoires of intra-epithelial T and B cells were consistently less diverse and more clonal than those of stromal T and B cells. T-cell receptor (TCR) sequencing confirmed a reduced diversity and higher clonality of intra-epithelial T cells relative to the corresponding stromal T cells. Analysis of the top 10 dominant clonotypes in the two compartments showed a majority of shared but also some unique clonotypes both in stromal and intra-epithelial T cells. Hyperexpanded clonotypes were more abundant among intra-epithelial than stromal T cells. These findings validate the ST-FFPE method and suggest an accumulation of antigen-specific T cells within tumor core. Because ST-FFPE is applicable for analysis of previously collected tissue samples, it could be useful for rapid assessment of intratumoral cellular heterogeneity in multiple disease and treatment settings.

Perforating Fibrous Histiocytoma Mimicking Keratoacanthoma: A Case Report.

A 31-year-old male presented with a firm, well-demarcated, erythematous, crateriform, and ulcerated nodule in the left lumbar region, which persisted for 3 months. Clinically, a keratoacanthoma was suspected. The histological analysis was consistent with perforating fibrous histiocytoma, a rare histopathologic variant of fibrous histiocytoma. To our knowledge, this is the third case reported in the literature.

Characteristics of long-survivor metastatic melanoma after polychemotherapy and interferon: a retrospective study.

BACKGROUND: The development of immunotherapy and tyrosine kinase inhibitors dramatically improved the prognosis of metastatic melanoma. Consequently, chemotherapy is now rarely used. Here, we describe the characteristics of long-surviving patients with metastatic melanoma treated with immunochemotherapy. MATERIAL AND METHODS: We retrieved retrospective clinical and pathological data for patients diagnosed with metastatic melanoma between January 1993 and December 2015 who received the CVD-INF (cisplatin, vinblastine, dacarbazine, and interferon α-2b) regimen at the Hôpitaux Universitaires de Genève. We estimated their progression-free survival and overall survival. This ad hoc study's primary aim was to describe the clinical and biological characteristics of long-term survivors, defined as patients surviving more than two years after immunochemotherapy initiation. The spatial distribution pattern of CD8+ T cells (inflamed, excluded, or desert) was immunohistochemically determined. RESULTS: Ninety patients received CVD-INF. Their median age at metastatic melanoma diagnosis was 55 years (20-75). Their median progression-free survival was 2.8 months, and median overall survival was 7.2 months. Eleven (12%) patients were long-term survivors. In multivariate analysis, central nervous system metastases (hazard ratio [HR]: 2.66; 95% confidence interval [CI]: 1.43-4.95; p = 0.001), multiple metastases (HR: 1.82; 95% CI: 1.01-3.29; p = 0.047), and elevated lactate dehydrogenase (LDH) (HR: 1.92; 95% CI: 1.12-3.30; p = 0.016) were independently associated with shorter survival. Most long-survivors (6/8; 75%) had a tumour-inflamed pattern compared to 25% of non-long survivors (5/20; Fisher's test p = 0.030). CONCLUSIONS: A subset of patients with metastatic melanoma and a tumour-inflamed phenotype treated with CVD-INF survived over two years. Factors associated with prolonged survival are consistent with those previously reported in metastatic melanoma.

IL-38 orchestrates proliferation and differentiation in human keratinocytes.

Interleukin (IL)-38 is a member of the IL-1 cytokine family with reported anti-inflammatory activity. The highest constitutive IL-38 expression is detected in the skin, where it is mainly produced by differentiating keratinocytes. However, little data are available regarding its biological functions. In this study, we investigated the role of IL-38 in skin physiology. We demonstrate here that dermal fibroblasts and epithelial cells of skin appendages, such as eccrine sweat glands and sebaceous glands, also express IL-38. Next, using two- and three-dimensional cell cultures, we show that endogenous expression of IL-38 correlates with keratinocyte differentiation and its ectopic overexpression inhibits keratinocyte proliferation and enhances differentiation. Accordingly, immunohistochemical analysis revealed downregulation of IL-38 in skin pathologies characterized by keratinocyte hyperproliferation, such as psoriasis and basal or squamous cell carcinoma. Finally, intracellular IL-38 can shuttle between the nucleus and the cytoplasm and its overexpression modulates the activity of the transcription regulators YAP and ID1. Our results indicate that IL-38 can act independently from immune system activation and suggest that it may affect the epidermis directly by decreasing proliferation and promoting differentiation of keratinocytes. These data suggest an important role of keratinocyte-derived IL-38 in skin homeostasis and pathologies characterized by epidermal alterations.

A New Case of Hybrid Epidermoid and Apocrine Cyst.

We described a new case of a hybrid epidermoid and apocrine cyst, known to be a rare histopathological entity. The cyst was located in the axillary region and completely excised, without complication. The diagnosis was made at the histological analysis, where we found a cystic lesion in the dermis, lined with both epidermoid and apocrine epithelium.

5-Hydroxymethylcytosine Loss in Conjunctival Melanoma.

AIMS: Conjunctival and cutaneous melanoma partially share similar clinical and molecular backgrounds. As 5-hydroxymethylcytosine (5-hmC) loss has been demonstrated in cutaneous melanoma, we decided to assess if similar changes were occurring in conjunctival melanoma. METHODS: 5-methylcytosine (5-mC), 5-hmC and TET2 were respectively identified by immunohistochemistry and RNA ISH in 40 conjunctival nevi and 37 conjunctival melanomas. Clinicopathological correlations were established. RESULTS: 5-mC, TET2 and 5-hmC were respectively identified in 67.5%, 95% and 100% of conjunctival nevi and in 81.1%, 35.1% and 54% of conjunctival melanomas. A significant 5-hmC and TET2 loss was identified in conjunctival melanoma comparing to nevus, as well as a significant correlation between TET2 and 5-hmC expression. In the melanomas, 5-hmC expression was only significantly associated with local lymphatic invasion, but not with other clinicopathological parameters. There was a correlation between TET2 expression and the localization of the tumors. 5-mC expression was not associated with any clinicopathological parameters. CONCLUSIONS: We identified a significant 5-hmC loss in conjunctival melanoma similar to cutaneous melanoma. This loss may possibly be attributed to TET2 loss or IDH1 mutations. 5-hmC loss in conjunctival melanoma may help in the differential diagnosis between atypical conjunctival nevus and conjunctival melanoma.

Pseudolymphomatous Granuloma Annulare: A Case Report.

Granuloma annulare is an idiopathic granulomatous condition. Clinical variants of granuloma annulare include classical and localized, large erythematous patch, generalized, perforating, and subcutaneous/deep forms. Rarely, granuloma annulare shows a prominent lymphoid infiltration. This form is called pseudolymphomatous granuloma annulare. Here, we describe a new case of pseudolymphomatous granuloma annulare.

Epidermolytic Acanthoma Mimicking Condyloma: A Case Report.

Epidermolytic acanthoma is a rare benign tumor that appears as a solitary papule or, rarely, multiple small papules on the trunk and extremities, or on genitalia. They are generally asymptomatic, although they can be pruritic. The clinical presentation is often misleading, and the lesions are often misdiagnosed histologically and frequently confused with condyloma acuminatum. Here, we report a case of an epidermolytic acanthoma on the penis of a 57-year-old male, whose final diagnosis was made after several years.

A Case of Compound Nevus with Intradermal Pseudoglandular Features: A Rare Variant and Possible Pitfall.

Melanocytic nevi are frequent cutaneous lesions with a large variation of morphological features, including pseudoglandular formation, which has rarely been described in the literature and remains of uncertain biological and clinical significance. We report a case of benign compound melanocytic nevus, with a dermal component showing an epithelioid proliferation arranged in small nests with central lumen-like structures mimicking glands. Immunohistochemical staining was necessary to determine the exact nature of the proliferation, since the tubular differentiation can be seen in benign and malignant epithelial neoplasms and has to be clearly identified to avoid misdiagnosis.

ß-Catenin Expression and Activation in Conjunctival Melanoma.

PURPOSE: To assess the role of the canonical Wnt pathway via activation of ß-catenin in tumor progression of conjunctival melanoma. METHODS: ß-Catenin localization was assessed by immunohistochemistry in 43 conjunctival nevi, 48 primary acquired melanoses (PAM; conjunctival melanocytic intraepithelial neoplasia), and 44 conjunctival melanomas. Activation of the canonical or the noncanonical Wnt pathway was tested in vitro in 4 conjunctival melanoma cell lines with stimulation of either Wnt5a or Wnt3a. Wound healing assays were performed with Wnt5a. RESULTS: Nuclear ß-catenin expression was found in 16% of the nevi, in 15% of the melanomas, and in 4% of the PAM. Membranous ß-catenin expression was identified in all the nevi and PAM and in 97.7% of the melanomas. In vitro, Wnt5a stimulation in the 4 conjunctival melanomas and in 1 skin melanoma cell line did not induce nuclear translocation of ß-catenin, nor did it increase cell motility in the wound healing assays. Wnt3a stimulation did not induce nuclear localization of ß-catenin in any of the cell lines tested. CONCLUSIONS: In conjunctival melanoma, nuclear localization and activation of ß-catenin appear to be limited, suggesting that inhibition of ARF6, responsible for ß-catenin activation, in subsets of skin melanoma may not represent a treatment option for this tumor. In vitro, Wnt3a or Wnt5a did not induce nuclear ß-catenin localization.

Conjunctival Melanoma Targeted Therapy: MAPK and PI3K/mTOR Pathways Inhibition.

Purpose: To analyze the activity of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinases/mechanistic target of rapamycin (PI3K/mTOR) pathways in benign and malignant conjunctival melanocytic proliferations and explore whether specific inhibitors can suppress growth of conjunctival melanoma (CJM) cells. Methods: The presence of a BRAF V600E mutation and activation of ERK, MEK, S6, and AKT were assessed with immunohistochemistry in 35 conjunctival nevi and 31 melanomas. Three CJM cell lines were used: CRMM1, carrying the BRAF V600E mutation; CRMM2, harboring the NRAS Q61L mutation; and T1527A, with a BRAF G466E mutation. WST-1 assays were performed with a BRAF inhibitor (vemurafenib), two MEK inhibitors (trametinib, selumetinib), a PI3K inhibitor (pictilisib), and a dual PI3K/mTOR inhibitor (dactolisib). The phosphorylation of ERK, MEK, and S6 were tested with western blots and apoptosis with cleaved caspase-3 immunostaining. Results: A BRAF V600E mutation was detected in 42.6% of nevi and in 35.5% of CJM. MEK and ERK activation were higher in CJM, occurring in 62.9% and 45.7% of the nevi and 90.3% and 96.8% of the CJM, respectively. There was also a significant increase in S6 activation in CJM (90.3%) compared with the nevi (20%). CRMM1 was sensitive to trametinib and the PI3K inhibitors but only marginally to vemurafenib. CRMM2 was moderately sensitive to pictilisib, whereas T1527A was resistant to all drugs tested. Conclusions: The MAPK pathway activity in CJM is increased, not only as a consequence of the BRAF V600E mutation. Targeted therapy may be useful for patients with CJM, especially those with activating BRAF mutations, whereas NRAS-mutated melanomas are relatively resistant.

Atypical Cellular Blue Nevus of the Foot: A Case Report.

Blue nevus is a congenital and acquired melanocytic proliferation that includes different histological types. The atypical cellular type has been rarely described and it classically has a benign course. However, because of its intermediate features between common blue nevus and malignant blue nevus, long-term clinical follow-up is required. Here we report the case of a 28-year-old woman who presented with an atypical cellular blue nevus on the right foot.

[A case of «â€ peau d'orange†¼ in the absence of cancer]. / Un cas de «â€ peau d'orange†¼ sans cancer.

A 57-year old female patient initially consulted a gynecologist for a cutaneous lesion on her left breast present since 6 weeks. The gynecologist described a plaque-like lesion in the sense of «â€…peau d'orange ¼. Imaging and a biopsy did not reveal evidence for a malignancy. When she presented in our «â€…walk-in ¼ outpatient clinic for a second opinion, a borreliosis was suspected based on the clinical appearance of the lesion. This hypothesis was confirmed by the -re-evaluation of the skin biopsy by a dermatopathologist and -further substantiated by positive serology. Thus, oral doxycycline (2 x 100 mg/day) for 28 days was prescribed as treatment, resulting in resolution of the lesion. We wish to encourage colleagues to contact a dermatologist for any unclear pathology of the skin and to send skin biopsies to a dermatopathologist, particularly if inflammatory or infectious diseases are suspected.

Une patiente de 57 ans a consulté initialement un gynécologue pour une lésion cutanée au niveau du sein gauche qui était présente depuis six semaines. Le gynécologue a décrit un placard de peau d'orange. Une biopsie cutanée n'a pas montré de lésion suspecte. Quand elle s'est présentée dans notre consultation, une borréliose a été suspectée sur le plan clinique. Une relecture des lames de la biopsie par un dermatopathologue a confirmé ce diagnostic. Etant donné la présence d'une sérologie positive, un traitement per os avec doxycycline pendant 28 jours a été réalisé. Nous encourageons nos collègues à solliciter un avis dermatologique, s'il y a un doute par rapport au diagnostic d'une ­pathologie qui touche la peau, et de profiter de l'expertise d'un dermato­pathologue pour lire les lames des biopsies cutanées.

Cutaneous Mucormycosis Resulting from Hematogenous Dissemination of Rhizomucor pusillus in an Immunocompromised Patient.

Rhizomucor pusillus is an opportunistic fungus that causes infections (mucormycosis) in patients with a predisposing disease, such as diabetes mellitus and immunodeficiency. Classic manifestations are sinus, pulmonary, and skin infections. Skin lesions consist of tender, erythematous, indurated, and necrotic plaques. The diagnosis is made by identification of the organisms by histopathological analysis of the lesion, showing nonseptate fungal hyphae in the dermis and invasion of the vessel walls, or by means of cultures. Amphotericin B and surgery are the treatments of choice.

Primordial germ cells as a potential shared cell of origin for mucinous cystic neoplasms of the pancreas and mucinous ovarian tumors.

Mucinous ovarian tumors (MOTs) morphologically and epidemiologically resemble mucinous cystic neoplasms (MCNs) of the pancreas, sharing a similar stroma and both occurring disproportionately among young females. Additionally, MOTs and MCNs share similar clinical characteristics and immunohistochemical phenotypes. Exome sequencing has revealed frequent recurrent mutations in KRAS and RNF43 in both MOTs and MCNs. The cell of origin for these tumors remains unclear, but MOTs sometimes arise in the context of mature cystic teratomas and other primordial germ cell (PGC) tumors. We undertook the present study to investigate whether non-teratoma-associated MOTs and MCNs share a common cell of origin. Comparisons of the gene expression profiles of MOTs [including both the mucinous borderline ovarian tumors (MBOTs) and invasive mucinous ovarian carcinomas (MOCs)], high-grade serous ovarian carcinomas, ovarian surface epithelium, Fallopian tube epithelium, normal pancreatic tissue, pancreatic duct adenocarcinomas, MCNs, and single-cell RNA-sequencing of PGCs revealed that both MOTs and MCNs are more closely related to PGCs than to either eutopic epithelial tumors or normal epithelia. We hypothesize that MCNs may arise from PGCs that stopped in the dorsal pancreas during their descent to the gonads during early human embryogenesis, while MOTs arise from PGCs in the ovary. Together, these data suggest a common pathway for the development of MCNs and MOTs, and suggest that these tumors may be more properly classified as germ cell tumor variants. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Sign of Leser-Trélat and Cutaneous T-Cell Lymphoma: A Rare Association.

Sign of Leser-Trélat is a rare paraneoplastic cutaneous manifestation, characterized by the sudden appearance and rapid increase in size and number of seborrheic keratoses, accompanied by pruritus. Edmund Leser and Ulysse Trélat described this sign in 1890. Since their first description, their conclusions have been considered controversial and some authors assert the absence of a causal link. It seems to be frequently associated with solid tumors and in particular gastrointestinal cancer. Here, we describe a new case associated with a cutaneous T-cell lymphoma and a partial response to extracorporeal photopheresis.

Cutaneous Adnexal Cysts Revisited: What We Know and What We Think We Know.

Cutaneous cysts have been classified by dermatopathologists in many different ways. Here, we propose a novel classification of cutaneous adnexal cysts according to their origin in the folliculosebaceous unit and the sweat glands. By examining the lining of the cystic structure, its origin can be easily identified. Epidermal cysts have an epithelial wall containing a granular layer with lamellar keratinization, indicating an infundibular origin. Tricholemmal cysts have an undulating epithelial wall with no granular layer and a compact keratinization, showing an isthmic origin. In steatocystoma, dermoid cyst, and folliculosebaceous hamartoma, the epithelial lining shows a crenulated appearance which is seen in the sebaceous duct. Hidrocystoma shows the characteristic cuboidal epithelial lining of sweat glands with decapitation secretion in its apocrine forms. The hair matrix cyst wall is composed of basaloid cells maturing to squamoid cells, as seen in the normal hair matrix and shadow cells in the lumen. Metabolizing acquired dioxin-induced skin hamartoma (MADISH) is a cystic lesion with lamellar keratinization, and no sebaceous glands. The classification proposed here aims to simplify the complexity of cutaneous adnexal cysts, and to facilitate a better understanding of the origin of cystic lesions of the skin.