Case report: Single-stage facial reanimation with bilateral lengthening temporalis myoplasties for immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome related developmental facial palsy.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare primary immunodeficiency, typically associated with clinical features of intractable diarrhoea, type 1 diabetes mellitus and eczema. We present a case of IPEX syndrome referred to our regional facial palsy service for smile restoration surgery. The patient presented with dissatisfaction of facial appearance, including mask-like facies and no functional smile. Pre-operative electromyography confirmed normal temporalis muscle activation. Consequently, the patient was offered single-stage bilateral lengthening temporalis myoplasties. The patient reported improved satisfaction with facial appearance. Surgery resulted in good early resting and voluntary symmetry. Oral commissures were elevated at rest improving oral incompetence. This is the first description of facial animation surgery in the context of IPEX syndrome. With careful consideration and patient selection, successful surgical restoration of resting symmetry and dynamic commissural smile can be achieved in this complex cohort of patients.

Time for consensus on "high-risk" - Sentinel lymph node biopsy for cutaneous squamous cell carcinoma: An international survey of skin cancer specialists and a literature update.

There is an urgent need for evidence-based management of cutaneous squamous cell carcinoma (cSCC), particularly "high-risk" tumours. We performed an online survey of skin cancer specialists to assess cSCC research priorities. Respondents were targeted via the international Skin Cancer OUTcomes consortium (SCOUT) and the UK regional Skin Cancer Outcomes North-East (SCONE) research interest group. Thirty-three respondents completed the survey ([46%; 16/33] were non-UK based). 'Defining a role for sentinel lymph node biopsy (SLNB) in high-risk cSCC' was most commonly ranked either 1st or 2nd research priority by respondents (55%; 18/33), with near-total consensus that SLNB could be useful for the early identification of nodal metastasis in high-risk cSCC (97%; 30/31). On this specific research priority, 24 studies with longitudinal follow-up data were identified. Cumulatively, SLNB for cSCC had positivity and false omission rates of 7.0% and 3.1%, respectively, with false negative rates of 29.0%. Given the lack of consensus on a definition of "high-risk" cSCC, it was unsurprising that only two studies of SLNB for head & neck cSCC utilised comparable selection criteria; reporting the highest positivity rates (8.0%) and lowest false-omission rates (2.4%) and false-negative rates (21.4%) overall. There is multi-disciplinary interest in the role of SLNB for "high-risk" cSCC. It appears to perform best in head and neck cases. A consensus definition of "high-risk" cSCC is urgently required to refine the utility of SLNB and guide risk-directed management.

Reduced SMAD2/3 activation independently predicts increased depth of human cutaneous squamous cell carcinoma.

The incidence of cutaneous squamous cell carcinoma (cSCC) is rising. Whilst the majority are cured surgically, aggressive metastatic cSCC carry a poor prognosis. Inactivating mutations in transforming growth factor beta (TGF-ß) receptors have been identified amongst genetic drivers of sporadic tumours and murine models of cSCC, suggesting a tumour suppressor function for TGF-ß in normal skin. However, paradoxically, TGF-ß acts as a tumour promoter in some murine model systems. Few studies have analysed the role of TGF-ß/activin signalling in human normal skin, hyper-proliferative skin disorders and cSCC. Antibodies recognising phospho-SMAD proteins which are activated during canonical TGF-ß/activin signalling were validated for use in immunohistochemistry. A tissue microarray comprising FFPE lesional and perilesional tissue from human primary invasive cSCC (n=238), cSCC in-situ (n=2) and keratocanthoma (n=9) were analysed in comparison with tissues from normal human scalp (n=10). Phosphorylated SMAD2 and SMAD3 were detected in normal interfollicular epidermal keratinocytes and were also highly localised to inner root sheath, matrix cells and Keratin 15 positive cells. Lesional cSCC tissue had significantly reduced activated SMAD2/3 compared to perilesional tissue, consistent with a tumour suppressor role for SMAD2/3 activators in cSCC. Increased cSCC tumour thickness inversely correlated with the presence of phospho-SMADs in tumour tissue suggesting that a reduction in canonical TGF-ß/activin signalling may be associated with disease progression.

Inactivation of TGFß receptors in stem cells drives cutaneous squamous cell carcinoma.

Melanoma patients treated with oncogenic BRAF inhibitors can develop cutaneous squamous cell carcinoma (cSCC) within weeks of treatment, driven by paradoxical RAS/RAF/MAPK pathway activation. Here we identify frequent TGFBR1 and TGFBR2 mutations in human vemurafenib-induced skin lesions and in sporadic cSCC. Functional analysis reveals these mutations ablate canonical TGFß Smad signalling, which is localized to bulge stem cells in both normal human and murine skin. MAPK pathway hyperactivation (through Braf(V600E) or Kras(G12D) knockin) and TGFß signalling ablation (through Tgfbr1 deletion) in LGR5(+ve) stem cells enables rapid cSCC development in the mouse. Mutation of Tp53 (which is commonly mutated in sporadic cSCC) coupled with Tgfbr1 deletion in LGR5(+ve) cells also results in cSCC development. These findings indicate that LGR5(+ve) stem cells may act as cells of origin for cSCC, and that RAS/RAF/MAPK pathway hyperactivation or Tp53 mutation, coupled with loss of TGFß signalling, are driving events of skin tumorigenesis.