The clinical and morphological picture of Merkel cell carcinoma (MCC) may be rather challenging; therefore, the immunohistochemical profile plays a relevant role in confirming the microscopic diagnosis. A panel of antibodies including cytokeratins 20, 7 and epithelial membrane antigen, and neuron-specific enolase is used in confirming the morphological diagnosis of MCC. The majority of MCCs express CK20 and are CK7-negative. Herein, we present a case of primary cutaneous neuroendocrine carcinoma with an atypical immunohistochemical pattern. A 83-years old woman presented with a painless plaque, red to violaceous in colour, located in the leg. The skin tumor was excided, formalin-fixed and paraffinembedded. Tissue sections were immunostained with a panel of antibodies routinely utilized in complex primary skin tumors for evidencing epithelial and neuroendocrine differentiation of tumor cells. The neuroendocrine differentiation of tumor cells was evidenced by their immunoreactivity for synaptophysin, chromograninA and neuron-specific enolase. Tumor cells also showed diffuse cytoplasmic staining for CK7. No immunoreactivity was detected for CK20 and thyroid transcription factor-1. Our data, together with previous rare reports of CK20−/CK7+ MCCs, lay stress on the importance of routinely utilizing a panel of antibodies in the differential diagnosis of complex primary carcinomas of the skin and may have important implications in expanding the differential diagnosis of skin tumors. In particular, caution should be taken in excluding the diagnosis of MCC only on the basis of the absence of reactivity of tumor cells for CK20, favouring the wrong diagnosis of less aggressive skin tumors.

Background Systemic sclerosis (SSc) is a systemic autoimmune disease characterized by vasculopathy and excessive production of collagen, which lead to skin and visceral fibrosis. The aim of our study is to assess the potential benefits of peripheral blood mononuclear cells (PB-MNCs) implants in the treatment of clinical manifestations such as mouth impairment, hand disability, digital ulcers and Raynaud’s phenomenon in Scleroderma patients. Methods From February 2016 to May 2019, 10 female patients were enrolled from the outpatient clinic of the Plastic Surgery Unit of Sapienza University of Rome. Parameters evaluated were: patients’ disability, using the Health Assessment Questionnaire (HAQ) disability index (DI) and the scleroderma HAQ (sHAQ); mouth opening capacity, by measuring the maximum interincisal distance and the mouth perimeter; hand mobility, assessed with clinical exam and the Hand Mobility in Scleroderma (HAMIS) scale; Raynaud’s phenomenon, evaluated through nailfold capillaroscopy; digital ulcers, examined through their features and incidence of appearance. SPSS software was used for a simple descriptive statistical analysis performed by the Student's paired t-test. P values less than 0.05 were considered statistically significant. Results The treatment showed a significant improvement of all the parameters evaluated at 1-year follow-up, it was well-tolerated by all the patients and the only complications noticed were small areas of ecchymosis. Conclusions Our results suggest that PB-MNCs injection could represent a treatment option to take into account for SSc patients. The procedure we used is easy and fast to perform, minimally invasive and not-operator dependent. We hope our observational and preliminary study could be considered as a starting point for further research studies.