Genome sequencing and analysis of the Tasmanian devil and its transmissible cancer.

The Tasmanian devil (Sarcophilus harrisii), the largest marsupial carnivore, is endangered due to a transmissible facial cancer spread by direct transfer of living cancer cells through biting. Here we describe the sequencing, assembly, and annotation of the Tasmanian devil genome and whole-genome sequences for two geographically distant subclones of the cancer. Genomic analysis suggests that the cancer first arose from a female Tasmanian devil and that the clone has subsequently genetically diverged during its spread across Tasmania. The devil cancer genome contains more than 17,000 somatic base substitution mutations and bears the imprint of a distinct mutational process. Genotyping of somatic mutations in 104 geographically and temporally distributed Tasmanian devil tumors reveals the pattern of evolution and spread of this parasitic clonal lineage, with evidence of a selective sweep in one geographical area and persistence of parallel lineages in other populations.

Dermoscopy of Lentiginous Melanomas and Equivocal Benign Pigmented Macules of the Scalp: A Case-Control Multicentric Study.

INTRODUCTION: Although the dermoscopic features of facial lentiginous melanomas (LM), including lentigo maligna and lentigo maligna melanoma, have been extensively studied, the literature about those located on the scalp is scarce. This study aims to describe the dermoscopic features of scalp LM and assess the diagnostic accuracy of dermoscopy to discriminate them from equivocal benign pigmented macules. METHODS: Consecutive cases of scalp LM and histopathology-proven benign but clinically equivocal pigmented macules (actinic keratoses, solar lentigos, seborrhoeic keratoses, and lichen planus-like keratoses) from four referral centres were included. Dermoscopic features were analysed by two blinded experts. The diagnostic performance of a predictive model was assessed. RESULTS: 56 LM and 44 controls were included. Multiple features previously described for facial and extrafacial LM were frequently identified in both groups. Expert's sensitivity to diagnose scalp LM was 76.8% (63.6-87.0) and 78.6% (65.6-88.4), with specificity of 54.5% (38.9-69.6) and 56.8% (41.0-71.7), and fair agreement (kappa coefficient 0.248). The strongest independent predictors of malignancy were (OR, 95% CI) chaos of colour (15.43, 1.48-160.3), pigmented reticular lines (14.96, 1.68-132.9), increased density of vascular network (3.45, 1.09-10.92), and perifollicular grey circles (2.89, 0.96-8.67). The predictive model achieved 85.7% (73.8-93.6) sensitivity, 61.4% (45.5-75.6) specificity, and 81.5 (73.0-90.0) area under curve to discriminate benign and malignant lesions. A diagnostic flowchart was proposed, which should improve the diagnostic performance of dermoscopy. CONCLUSION: Both facial and extrafacial dermoscopic patterns can be identified in scalp LM, with considerable overlap with benign pigmented macules, leading to low specificity and interobserver agreement on dermoscopy.

Dermoscopic-Guided Shave Removal of Acquired Facial Melanocytic Nevi in Dark-Skinned Individuals.

BACKGROUND: Acquired melanocytic nevi are common benign skin lesions that require removal under certain circumstances. Shave removal is a straightforward treatment modality with a risk of recurrence. OBJECTIVE: To evaluate the outcome of dermoscopy-guided shave removal of acquired melanocytic nevi in the face of dark-skinned individuals who are more liable to postsurgical complications. METHODS: The study was conducted on 64 patients with acquired facial melanocytic nevi. Serial shave removal using a razor blade guided by dermoscopic examination was done until nevus-free tissue was seen, followed by electrocauterization of the base. Cosmetic outcome, patients' satisfaction, and recurrence rate were evaluated during follow-up. RESULTS: Excellent cosmetic outcome was achieved in 54.69% of patients, while 39.06% had an acceptable outcome, and 6.25% of patients had poor cosmetic outcome. Meanwhile, the recurrence rate was noticed in 5 cases only (7.8%). CONCLUSION: Dermoscopic-guided shave removal provides an easy procedure of treating common melanocytic nevi with an acceptable cosmetic result and a lower rate of recurrence even in patients with darker skin phenotypes.

Two Cases of Cutaneous Sarcomatoid Squamous Cell Carcinoma Resembling Cutaneous Giant Cell Tumor of Soft Tissue.

ABSTRACT: Cutaneous sarcomatoid squamous cell carcinoma is well-described with histology resembling pleomorphic undifferentiated sarcoma featuring collagenous or myxoid stroma with or without elements of keratinizing squamous carcinoma. This report presents 2 cases of dedifferentiated squamous cell carcinoma (SCC) composed of sheets of malignant mononuclear cells with malignant osteoclast-like multinucleated giant cells, extravasated blood, and hemosiderin resembling cutaneous giant cell tumor (cGCT). In the first case, an exophytic facial mass of a 96-year-old woman removed by shave showing extensive cGCT-like tumor but with microscopic elements of SCC in situ and positivity for cytokeratin 5/6 in the malignant spindle cells and SCC. The second case involved a 32-year-old man with a pedunculated penile mass removed by shave biopsy, displaying malignant cytology resembling cGCT, focal staining for cytokeratin AE1/AE3 and p63, and CD68 highlighting the osteoclast-like giant cells. Molecular analysis revealed CDKN2A, TP53, and TERT. Upon reexcision, case 2 showed focally invasive keratinizing SCC associated with differentiated penile intraepithelial neoplasia and lichen sclerosus. Skin specimens with an exophytic mass histologically resembling cGCT but with malignant cytology should be meticulously evaluated for elements of SCC. Molecular analysis, detecting mutations like H3F3 or HMGA2-NCOR2 fusion, can aid in distinguishing cutaneous sarcomatoid squamous cell carcinoma from GCT bone or GCT soft tissue.

Advances in Diagnosis and Treatment of Basal Cell Carcinoma.

Basal cell carcinoma (BCC) is one among the most prevalent malignant neoplasms that has exhibited a notable surge in global incidence over recent decades. This slow-growing malignancy is typified by its localized invasiveness while demonstrating an exceedingly rare metastatic proclivity. It predominantly afflicts the sun-exposed skin of aging individuals, with a heightened predilection for the maxillofacial region. Scraping cytology offers numerous benefits, including the potential for an earlier diagnosis and the absence of scarring, as opposed to a biopsy. The cytodiagnosis of BCC proves to be straightforward with various techniques, making it highly advantageous in an outpatient environment as a swift diagnostic method when planning a surgical excision. Our study sought to scrutinize the clinicopathological facets of BCC within the maxillofacial region. We compared advanced cytological techniques for diagnosis, including scraping, scratching, and imprinting using Papanicolau and Diff-Quick stains. In addition, we evaluated the therapeutic effectiveness of diode lasers operating at wavelengths of 940nm and 980n. A retrospective analysis was undertaken, encompassing facial BCC lesions smaller than 2.5 cm in diameter that underwent treatment through diode laser ablation between September 2021 and August 2023 at Ramadi Teaching Hospital and a private clinic in Ramadi City, Iraq. Among the cohort of 48 patients with BCC, a majority (58%) were 50 years of age or older, with a predominance of males (62%). The mean duration of lesion existence exceeded 4 months. The anatomical region most commonly involved was the middle 1/3 of the face, accounting for 34% of cases. Intriguingly, the therapeutic approach of diode laser ablation yielded exceptional esthetic and functional outcomes, which were consistently observed throughout the follow-up period post-healing. The occurrence of complications following diode laser ablation was relatively infrequent. This investigation revealed that cytological examination is easily conducted, eliminating the need for local anesthesia, saving time, being more cost-effective than a conventional biopsy, and delivering swift diagnoses. The process of smear-taking for cytology is well-tolerated, inflicting minimal trauma or discomfort on the patient. BCC predominantly afflicts elderly males and most frequently affects the middle third of the face. Notably, nodular BCC emerged as the prevailing histological subtype. The use of diode laser ablation exhibited a commendable track record, producing exemplary functional and esthetic outcomes over a 6-month follow-up period.

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) in a 15-Year-old male presenting with orofacial Swelling.

BACKGROUND: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of non-Hodgkin lymphoma that primarily affects subcutaneous tissues. Its occurrence in the orofacial region is exceptionally uncommon, presenting diagnostic challenges due to symptom overlap with more prevalent orofacial condition. CASE PRESENTATION: This report details the case of a 15-year-old male who presented with persistent left-sided facial swelling, initially misdiagnosed as facial cellulitis. Diagnostic complexity arose from the similarity of symptoms to common orofacial diseases. Comprehensive diagnostic approaches, including liquid-based thin-layer cytometry, immunohistochemistry, and advanced imaging, were pivotal in identifying SPTCL. The recurrence of symptoms following the cessation of dexamethasone treatment indicated hormone dependency. Surgical intervention and subsequent histopathological analysis confirmed SPTCL, with immunohistochemical profiling playing a critical role in the definitive diagnosis. The patient's management involved a multidisciplinary approach, leading to a referral to a hematology specialist and subsequent favorable outcomes. CONCLUSIONS: This case underscores the diagnostic challenges of orofacial lymphomas such as SPTCL and highlights the necessity for early, accurate pathological diagnosis. It emphasizes the role of advanced diagnostic techniques and the importance of a comprehensive, multidisciplinary approach in the management of such rare cases. This report contributes to the limited but growing body of literature on SPTCL in the orofacial region, providing insights for clinicians in similar future cases.

A case of melanoma in situ of the central forehead repair by V-Y advancement flap and Burow graft.

Large defects on the face after Mohs surgery have posed significant reconstructive challenges. A 90-year-old man presented with melanoma in situ of the central forehead, which resulted in a 4.5cmx4.3cm defect after multiple stages of Mohs surgery. Although different approaches for forehead repair with nasal root involvement are possible, we demonstrate that the V-Y advancement flap and subsequent Burrow graft for nasal root repair represents a viable closure technique for large circular defects of the central forehead.

Fast and safe clinical response to sonidegib in a 98-year old woman affected by locally advanced basal cell carcinoma.

A 98-year-old woman presented with histologically confirmed locally advanced basal cell carcinoma of the face. A multidisciplinary approach excluded surgery because of the site near sensitive organs, extension, age, and comorbidities. Patient and caregivers declined radiotherapy considering the necessity of multiple hospital appointments. The patient was then placed on therapy with sonidegib, an oral inhibitor of the Hedgehog signaling pathway. There was a very rapid clinical response after only 28 days of treatment. The basal cell carcinoma improved progressively, with no adverse events reported. This case illustrates the efficacy and safety of this treatment in an advanced age patient. This treatment had a remarkably positive impact on quality of life, including that of the caregivers.

Congenital orofacial teratoma in a 22-week foetus.

No abstract available.

Reflectance confocal microscopy of facial neoplasms: Follicular involvement as a clue to diagnosis.

BACKGROUND: Facial skin is characterized by high density of follicles. Facial neoplasms may present overlapping clinical and dermoscopic findings. Our goal was to evaluate and compare, via reflectance confocal microscopy (RCM), follicular involvement in facial neoplasms. METHODS: We retrospectively searched our image database, between January 2008 and December 2020, for all facial lesions with (1) a standardized set of clinical, dermoscopic, and RCM images, and (2) a biopsy-proven diagnosis of lentigo maligna/lentigo maligna melanoma (LM/LMM, n = 39), basal cell carcinoma (BCC, n = 51), squamous cell carcinoma in situ (SCCIS, n = 5), actinic keratosis (AK, n = 11), and lichen-planus-like keratosis (LPLK, n = 18). Two readers jointly evaluated the RCM images for a set of predefined features of follicular involvement. RESULTS: Diffuse obliteration of follicles was frequent in BCC (88%), while follicular infiltration by refractile dendritic cells and/or by bright round nucleated cells was common in melanoma (90% and 44%, respectively). Extension of atypical keratinocytes down follicles was more prominent among SCCIS than AK (80% vs. 45%, p = 0.01). In most LPLK (89%), there was follicular sparing. CONCLUSIONS: Evaluation of RCM criteria centering on the follicles can be useful in the differential diagnosis between common facial neoplasms.

A risk-scoring model for the differential diagnosis of lentigo maligna and other atypical pigmented facial lesions of the face: The facial iDScore.

BACKGROUND: Due to progressive ageing of the population, the incidence of facial lentigo maligna (LM) of the face is increasing. Many benign simulators of LM and LMM, known as atypical pigmented facial lesions (aPFLs-pigmented actinic keratosis, solar lentigo, seborrheic keratosis, seborrheic-lichenoid keratosis, atypical nevus) may be found on photodamaged skin. This generates many diagnostic issues and increases the number of biopsies, with a subsequent impact on aesthetic outcome and health insurance costs. OBJECTIVES: Our aim was to develop a risk-scoring classifier-based algorithm to estimate the probability of an aPFL being malignant. A second aim was to compare its diagnostic accuracy with that of dermoscopists so as to define the advantages of using the model in patient management. MATERIALS AND METHODS: A total of 154 dermatologists analysed 1111 aPFLs and their management in a teledermatology setting: They performed pattern analysis, gave an intuitive clinical diagnosis and proposed lesion management options (follow-up/reflectance confocal microscopy/biopsy). Each case was composed of a dermoscopic and/or clinical picture plus metadata (histology, age, sex, location, diameter). The risk-scoring classifier was developed and tested on this dataset and then validated on 86 additional aPFLs. RESULTS: The facial Integrated Dermoscopic Score (iDScore) model consisted of seven dermoscopic variables and three objective parameters (diameter ≥ 8 mm, age ≥ 70 years, male sex); the score ranged from 0 to 16. In the testing set, the facial iDScore-aided diagnosis was more accurate (AUC = 0.79 [IC 95% 0.757-0.843]) than the intuitive diagnosis proposed by dermatologists (average of 43.5%). In the management study, the score model reduced the number of benign lesions sent for biopsies by 41.5% and increased the number of LM/LMM cases sent for reflectance confocal microscopy or biopsy instead of follow-up by 66%. CONCLUSIONS: The facial iDScore can be proposed as a feasible tool for managing patients with aPFLs.

Transmissible cancer and longitudinal telomere dynamics in Tasmanian devils (Sarcophilus harrisii).

A plethora of intrinsic and environmental factors have been shown to influence the length of telomeres, the protector of chromosome ends. Despite the growing interest in infection-telomere interactions, there is very limited knowledge on how transmissible cancers influence telomere maintenance. An emblematic example of transmissible cancer occurs in the Tasmanian devil (Sarcophilus harrisii), whose populations have been dramatically reduced by infectious cancer cells. To investigate associations between telomere dynamics and the transmissible cancer, we used longitudinal data from a Tasmanian devil population that has been exposed to the disease for over 15 years. We detected substantial temporal variation in individual telomere length (TL), and a positive significant association between TL and age, as well as a marginally significant trend for devils with devil facial tumour disease (DFTD) having longer telomeres. A proportional hazard analysis yielded no significant effect of TL on the development of DFTD. Like previous studies, we show the complexity that TL dynamics may exhibit across the lifetime of organisms. Our work highlights the importance of long-term longitudinal sampling for understanding the effects of wildlife diseases on TL.

A review of the evidence for Mohs micrographic surgery. Part 2: basal cell carcinoma.

Mohs micrographic surgery (MMS) is considered the gold-standard treatment for basal cell carcinoma (BCC) particularly for sites with a high-risk of incomplete excision such as the central face, for tumours with an aggressive growth pattern and consequent unpredictable subclinical extension and for recurrent tumours. However, the process is more time-consuming than for standard excision (SE), and the magnitude of benefit is uncertain. This article aims to provide a more complete picture of current evidence, including a review of cosmetic outcomes, tissue-sparing ability and cost-effectiveness of MMS. Although robust evidence is lacking, there is a large volume of observational data supporting a low recurrence rate after MMS. The risk of incomplete excision and higher recurrence rate of standard excision favours the use of MMS at high-risk sites. There is some low-certainty evidence that MMS results in a smaller defect size compared with SE, and that incomplete excision with SE results in larger defects. Larger defects may affect cosmetic outcome but there is no direct evidence that MMS improves cosmetic outcome compared with SE. There is conflicting evidence regarding the cost of MMS compared with SE, as some studies consider MMS less expensive than SE and others consider it more expensive, which may reflect the healthcare setting. A multicentre 10-year randomized controlled trial comparing MMS and SE in the treatment of high-risk BCC would be desirable, but is unlikely to be feasible or ethical. Collection of robust registry data capturing both MMS and SE outcomes would provide additional long-term outcomes.

Inferiorly Based Rotation Flaps for Infraorbital Cheek Defects.

BACKGROUND: The infraorbital cheek is a common location for cutaneous malignancy and thus surgical defects. Reconstruction in this region must maintain nearby free margins to ensure optimal cosmetic and functional outcomes. Large defects may require a flap using lateral or inferior tissue reservoirs. OBJECTIVE: To examine outcomes of inferiorly based rotation flaps in the repair of infraorbital cheek defects and highlight pearls for optimal long-term results. METHODS: Chart review of patients with a defect of the infraorbital cheek repaired with an inferiorly based rotation flap between February 2010 and December 2018 at a single academic institution. The Visual Analog Scale (VAS) was used for scar assessment. RESULTS: Sixty-five patients underwent extirpation of a cutaneous malignancy resulting in defects ranging from 1.0 × 1.0 to 4.5 × 5.5 cm (mean area = 4.8 cm2). Most of the patients did not experience complications. Ectropion occurred in 7 patients. The mean VAS score was 11.6. CONCLUSION: An inferiorly based rotation flap yields acceptable outcomes for infraorbital cheek defects and can be considered for defects as large as 5.5 cm. Using pearls for surgical execution presented in this article may allow reconstructive surgeons to include this flap in their repertoire.

Rhabdomyomatous mesenchymal hamartoma presenting as a chin nodule in a 15-year-old male.

Rhabdomyomatous mesenchymal hamartoma (RMH), also known as congenital midline hamartoma and striated muscle hamartoma, is a rare congenital malformation presenting most commonly in midline sites of the head and neck region. Since its first description in 1986, 67 cases have been reported to date. We report a case of RMH presenting as a chin nodule in an otherwise healthy 15-year-old male. The patient presented with a dome-shaped subcutaneous lesion on his chin which had been present since birth, but had grown and was interfering with his ability to shave. He otherwise had no history of congenital anomalies or malformations. Histopathological examination of the excised lesion revealed a haphazard proliferation of striated muscle admixed with adipose tissue and adnexal structures within the dermis and subcutaneous tissue, consistent with a diagnosis of RMH. While the majority of reported cases are of newborns or children under 3 years of age, RMH may not come to clinical attention until later in life. This rare malformation should be included in the differential diagnosis of lesions containing dermal striated muscle and/or adipose tissue, to include nevus lipomatosus superficialis, fibrous hamartoma of infancy, neuromuscular choristoma, fetal rhabdomyoma, and rhabdomyosarcoma.

A novel aberration of COL1A1-PDGFB fusion as an insertion in chromosome 15 in one case of dermatofibrosarcoma protuberans involving a rare location.

Dermatofibrosarcoma protuberans (DFSP) is a rare sarcoma of the skin arising from the dermis. Its location is most commonly presented on the trunk of middle-aged adults and rarely on the face. The characteristic genetic aberration in the form of a reciprocal translocation t(17;22)(q21;q13) or a ring fusing the COL1A1 and PDGFB genes is found in 90% of DFSP. We present a case of a 42-year-old man who presented with a DFSP on the left cheek with foci of myxoid-fibrosarcomatous transformation. A conventional chromosomal analysis revealed a complex karyotype without a supernumerary ring chromosome or a linear translocation t(17;22). Comparative genome hybridization and fluorescence in-situ hybridization revealed the fusion of COL1A1 and PDGFB probes inserted in chromosome 15. This is a unique case of DFSP characterized by a rare body location, unique histopathological features, and novel chromosome COL1A1-PDGFB insertion, and may help guide future diagnostic and patient care modalities.

Histopathological characteristics and CD163 immunostaining pattern in fibrous papule of the face.

BACKGROUND: Signs of inflammation including epidermal interface changes, spongiosis, and dermal inflammation as well as pagetoid dyskeratosis are rarely described in fibrous papule (FP). We aimed to describe the inflammatory parameters, the rate of pagetoid dyskeratosis, along with CD163 immunohistochemical staining as an adjunctive diagnostic tool in FP. METHODS: Histopathology samples of all biopsy-proven FP cases were retrieved from archives and investigated for inflammatory parameters, presence of pagetoid dyskeratosis, as well as CD163, CD10, and CD34 immunostaining pattern of dermal spindle/stellate or multinucleate cells (graded from 0 to 4). RESULTS: Thirty-two cases of FP were identified. A high rate of inflammatory parameters including interface changes (20/32), spongiosis (31/32), and dermal lymphocytic inflammation (31/32) were detected. Pagetoid dyskeratosis was identified in eight out of 32 cases (25%). A grade 4 staining revealing a strong dendritic pattern was confirmed in all FP cases with CD163 immunohistochemistry including atypical variants such as granular FP, compared with CD10 (11/32) and CD34 (3/32). CONCLUSION: The dendritic cellular proliferation in FP may represent an inflammatory response to various stimuli; pagetoid dyskeratosis is a relatively common and underrecognized epidermal feature and CD163 immunostaining may be used as an adjunctive diagnostic tool in unusual histopathological subtypes.

The Efficacy of Everolimus for Facial Angiofibromas in Tuberous Sclerosis Complex Patients Treated for Renal Angiomyolipoma/Subependymal Giant Cell Astrocytoma.

BACKGROUND: Facial angiofibromas may be present since early childhood in individuals with tuberous sclerosis complex (TSC), causing substantial cosmetic disfigurement. Current therapies are partially effective, but they are uncomfortable, produce scarring, and are especially expensive. OBJECTIVE: The aim of the present study was to evaluate the efficacy of oral everolimus for TSC-associated angiofibromas. METHODS: This retrospective study included TSC patients being treated with oral everolimus for subependymal giant cell astrocytomas (SEGAs) and angiomyolipomas (AMLs). We recorded the changes in facial angiofibromas. Changes in the Angiofibroma Grading Scale (AGS) indicators were recorded according to erythema, average lesion size, lesion density, and percent involvement on the forehead, nose, cheeks, and chin. The scores were recorded before and after the administration of oral everolimus. RESULTS: Twenty-one patients being treated with oral everolimus were enrolled in this study. The mean age was 20.5 years (range 11-44 years, 4 males, and 17 females). The mean dose of oral everolimus was 3.6 mg/day. Clinically meaningful and statistically significant improvement was observed in erythema (p = 0.001), average lesion size (p < 0.001), lesion density (p < 0.001), and percent involvement (p < 0.001). Changes in the AGS findings were statistically significant on the forehead (p = 0.001), nose (p < 0.001) cheeks (p < 0.001), and chin (p = 0.004). CONCLUSION: Everolimus shows evident improvement and is approved for TSC-associated SEGAs and AMLs. The current study demonstrated the efficacy of oral everolimus in reducing facial angiofibromas, showing the parallel benefits of the treatment protocol for TSC.

Curse of the devil: molecular insights into the emergence of transmissible cancers in the Tasmanian devil (Sarcophilus harrisii).

The Tasmanian devil (Sarcophilus harrisii) is the only mammalian species known to be affected by multiple transmissible cancers. Devil facial tumours 1 and 2 (DFT1 and DFT2) are independent neoplastic cell lineages that produce large, disfiguring cancers known as devil facial tumour disease (DFTD). The long-term persistence of wild Tasmanian devils is threatened due to the ability of DFTD cells to propagate as contagious allografts and the high mortality rate of DFTD. Recent studies have demonstrated that both DFT1 and DFT2 cancers originated from founder cells of the Schwann cell lineage, an uncommon origin of malignant cancer in humans. This unprecedented finding has revealed a potential predisposition of Tasmanian devils to transmissible cancers of the Schwann cell lineage. In this review, we compare the molecular nature of human Schwann cells and nerve sheath tumours with DFT1 and DFT2 to gain insights into the emergence of transmissible cancers in the Tasmanian devil. We discuss a potential mechanism, whereby Schwann cell plasticity and frequent wounding in Tasmanian devils combine with an inherent cancer predisposition and low genetic diversity to give rise to transmissible Schwann cell cancers in devils on rare occasions.

Two of a kind: transmissible Schwann cell cancers in the endangered Tasmanian devil (Sarcophilus harrisii).

Devil facial tumour disease (DFTD) comprises two genetically distinct transmissible cancers (DFT1 and DFT2) endangering the survival of the Tasmanian devil (Sarcophilus harrisii) in the wild. DFT1 first arose from a cell of the Schwann cell lineage; however, the tissue-of-origin of the recently discovered DFT2 cancer is unknown. In this study, we compared the transcriptome and proteome of DFT2 tumours to DFT1 and normal Tasmanian devil tissues to determine the tissue-of-origin of the DFT2 cancer. Our findings demonstrate that DFT2 expresses a range of Schwann cell markers and exhibits expression patterns consistent with a similar origin to the DFT1 cancer. Furthermore, DFT2 cells express genes associated with the repair response to peripheral nerve damage. These findings suggest that devils may be predisposed to transmissible cancers of Schwann cell origin. The combined effect of factors such as frequent nerve damage from biting, Schwann cell plasticity and low genetic diversity may allow these cancers to develop on rare occasions. The emergence of two independent transmissible cancers from the same tissue in the Tasmanian devil presents an unprecedented opportunity to gain insight into cancer development, evolution and immune evasion in mammalian species.