Facial Merkel cell carcinoma in a patient with diabetes and hepatitis B:A case report

BACKGROUND Patients with chronic inflammatory disorders are at a higher risk of developing aggressive Merkel cell carcinoma(MCC). Diabetes is a common chronic inflammatory disease that is possibly associated with MCC;however, there are still no reports on the association between hepatitis B virus(HBV) infection and MCC. Whether there is an association between these three diseases and the specific mechanisms behind their effects is worth further research in the future.CASE SUMMARY We herein report a rare case of MCC with extracutaneous and nodal invasion in an Asian individual with type 2 diabetes mellitus and chronic HBV infection, but no immunosuppression or other malignancies. Such cases are uncommon and have rarely been reported in the literature. A 56-year-old Asian male presented with a significant mass on his right cheek and underwent extensive resection combined with parotidectomy, neck lymphadenectomy, and split-thickness skin grafting. Based on the histopathological findings, a diagnosis of MCC involving the adipose tissue, muscle, nerve, and parotid gland with lymphovascular invasion was made. Subsequently, he received radiotherapy with no adverse reactions.CONCLUSION MCC is a rare, aggressive skin cancer with frequent local recurrence, nodal invasion, and metastasis, which usually arises in older people of the white race. Patients with chronic inflammatory disorders are at a higher risk of developing aggressive MCC. The diagnosis can be confirmed with histology and immunohistochemistry. For localized MCC, surgery is the preferred treatment option. However, for advanced MCC, radiotherapy and chemotherapy have proven to be effective. In cases where chemotherapy is not effective or in the advanced stages of MCC, immune therapy plays an important role in treatment. As with any rare disease, the management of MCC remains an enormous challenge for clinicians;thus, follow-up should be individualized and future progress needs multidisciplinary collaborative efforts. Furthermore, physicians should include MCC in their list of possible diagnoses when they come across painless, rapidly growing lesions, particularly in patients with chronic HBV infection or diabetes, as these patients are more susceptible to the development of this condition and it tends to be more aggressive in them.

Long-term response to avelumab and management of oligoprogression in Merkel cell carcinoma:A case report

BACKGROUND Merkel cell carcinoma(MCC)is a rare and aggressive cutaneous neuroendocrine neoplasia,with high risk of recurrence and metastasis and poor survival.Immune checkpoint inhibitors,like the anti-programmed death-ligand 1 agent avelumab,were recently approved for the treatment of advanced MCC.We,herein,report the first case of advanced MCC with oligoprogression managed with avelumab and local radical treatment.CASE SUMMARY A 61-year-old man was presented to the hospital with sporadic fever and an exudative malodorous mass(10 cm of diameter),located on the right gluteal region.The final diagnosis was MCC,cT4N3M1c(AJCC,TNM staging 8th edition,2017),with invasion of adjacent muscle,in-transit metastasis,and bone lesions.Patient started chemotherapy(cisplatin and etoposide),and after six cycles,the main tumor increased,evidencing disease progression.Two months later,the patient started second line treatment with avelumab(under an early access program).After two cycles of treatment,the lesion started to decrease,achieving a major response.Local progression was documented after 16 cycles.However,as the tumor became resectable,salvage surgery was performed,while keeping the systemic treatment with avelumab.Since the patient developed bilateral pneumonia,immunotherapy was suspended.More than 2.5 years after surgery(last 19 mo without systemic therapy),the patient maintains complete local response and stable bone lesions.CONCLUSION This report highlights the efficacy and long-term response of avelumab on the management of a chemotherapy resistant advanced MCC,with evidence of oligoprogression,in combination with local radical treatment.

Neuroendocrine tumors:current therapies,notch signaling,and cancer stem cells

Neuroendocrine tumors(NETs)encompass a broad spectrum of malignancies all derived from neuroendocrine cell lineage,affecting many different organs including the gastrointestinal(GI)tract,the endocrine pancreas,the thyroid,the skin and the respiratory tract.These tumors as a group are very heterogeneous,with varying characteristics attributed to each tissue of origin and tumor subtype.The pathogenesis of the different subtypes of NETs is not fully understood,but recent studies suggest the Notch signaling pathway may be dysregulated in these tumors either by under or overexpression of Notch receptors and/or ligands,or by disruption of pathway functionality through other means.Notch receptors can function as tumor suppressors in some cellular contexts and oncogenes in others which may,in part,account for the wide range of phenotypes present in NETs.Cancer stem cells are present in these tumors and may be responsible for the high rate of chemotherapy resistance,recurrence and metastasis.The heterogeneity of NETs suggests that to fully understand the role of Notch signaling and the therapeutic implications thereof,a comprehensive and systematic analysis of Notch expression and function across all NET subtypes is required.Here we outline the current knowledge base with respect to current therapies and Notch signaling in neuroendocrine tumors of the lung,skin,thyroid,GI tract and endocrine pancreas.

Concurrence of Merkel Cell Carcinoma and Squamous Cell Carcinoma in A Patient with Generalized Actinic Keratosis: A Case Report

Introduction:Merkel cell carcinoma(MCC)is a rare,aggressive cutaneous malignancy,and its pathogenesis might relate to ultraviolet light and Merkel cell polyomavirus infection.MCC in the Chinese population is uncommon.Here,we present a case of MCC that occurred based on widespread actinic keratosis(AK)in a Chinese female.Case report:An 82-year-old woman presented with two rapidly enlarging and rupture lesions on the face for 1 year.Biopsy was suggestive of squamous cell carcinoma(SCC)on the forehead and MCC on the left cheek.The patient had a history of generalized AK for 3 years.The lesion on the left cheek was also revealed as an AK by histopathological examination 1 year ago.Complete surgical resection was performed to remove the two malignancies.Discussion:The co-occurrence of AK,SCC,and MCC in a Chinese woman is unusual.Immunohistopathological examination is vital for correct diagnosis.The three tumors,in this case,may originate from two different precursor cells and are affected by the same carcinogen.Alternatively,they may come from the same pluripotent epidermal stem cells,and chronic exposure to ultraviolet light and Merkel cell polyomavirus lead to the formation of different types of tumors.The coexist of MCC with other cutaneous tumors provided a train of thought for exploring the origin of MCC.Conclusion:We reported a rare co-existence phenomenon of MCC associated with AK and SCC.Hence,long-term follow-up and early treatment are imperative for patients with premalignant lesions,such as widespread AK.

Merkel cell carcinoma responsive to Etoposide:a case report and brief literature review

Merkel cell carcinoma(MCC),first described in 1972,is an aggressive primary cutaneous carcinoma able to incorporate both epithelial and neuroendocrine features.MCC mainly appears in individuals in their eighth decade and it is related to a high mortality rate.The etiology of this rare disease is not well-understood but ultraviolet radiation exposure,immune suppression,and aging have a consistent role in its pathogenesis.Usually,clinical lesions appear as asymptomatic coloured dermal nodules.The tumour can involve lymph nodes but further evaluation with imaging is recommended.The common approach for localized disease is surgical.This work reports a case of an 86-year-old man with locally advanced MCC where,based on clinical experience,oral mono-chemotherapy with single-agent etoposide was chosen as first-line therapy.A complete objective response was achieved in 2 months.

Recurrent Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an uncommon,potentially lethal and cutaneous tumor that mainly occurson the sun-exposed skin of the head and neck area in theelderly. It is 100 times less observed than melanoma. Wepresent here a case report of recurrent MCC in a Chineseman.

The anatomy, function, and development of mammalian Aβ low-threshold mechanoreceptors

t Touch sensation is critical for our social and environmental interactions. In mammals, most discriminative light touch sensation is mediated by the Aβ low-threshold mechanoreceptors. Cell bodies of Aβ low-threshold mechanoreceptors are located in the dorsal root ganglia and trigeminal ganglia, which extend a central projection innervating the spinal cord and brain stem and a peripheral projection innervating the specialized mechanosensory end organs. These specialized mechanosensory end organs include Meissner＇s corpuscles, Pacinian corpuscles, lanceolate endings, Merkel cells, and Ruffini corpuscles. The morphologies and physiological properties of these mechanosensory end organs and their innervating neurons have been investigated for over a century. In addition, recent advances in mouse genetics have enabled the identification of molecular mechanisms underlying the development of Aβ low- threshold mechanoreceptors, which highlight the crucial roles of neurotrophic factor signaling and transcription factor activity in this process. Here, we will review the anatomy, physiological properties, and development of mammalian low- threshold Aβ mechanoreceptors.