Schwannian and Perineuriomatous Differentiation in a Series of Giant Congenital Melanocytic Nevi.

ABSTRACT: Close relationship between melanocytes and neural cells is accepted to reflect their common derivation from the neural crest and tumors combining both elements. We present a series of 10 patients with giant congenital melanocytic nevi (CMN) in which a secondary proliferation (11 lesions) with schwannian and/or perineuriomatous differentiation developed in the course of the disease. The age of the patients (4 male and 6 female) at the time of surgery and histological assessment varied from 3 months to 57 years. Histopathologically, the following subgroups were delineated: (1) nodular/tumoriform "neurotization" in CMN, (2) diffuse neurofibroma-like proliferation within CMN, (3) plexiform neurofibroma-like proliferation within CMN, and (4) diffuse perineuriomatous (hybrid schwannomatous-perineuriomatous) differentiation in CMN. We review the pertinent literature, including the role of recently identified Schwann cell precursors which are believed to represent the nerve-associated state of neural crest-like cells that persists into later developmental stages.

Cumulative incidence and risk factors for cutaneous squamous cell carcinoma metastases in organ transplant recipients: The Skin Care in Organ Transplant Patients in Europe-International Transplant Skin Cancer Collaborative metastases study, a prospective multicenter study.

INTRODUCTION: Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. METHODS: In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2 years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. RESULTS: Of 514 SOTRs who presented with 623 primary cSCCs, metastases developed in 37 with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size > 2 cm, clinical ulceration, poor differentiation grade, perineural invasion, and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9%-68.4%). CONCLUSIONS: SOTRs have a high risk of cSCC metastases and well-established clinical and histologic risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis.

Topical bimatoprost in the treatment of eyelash loss in alopecia totalis and universalis: A prospective, open-label study.

Bimatoprost is a synthetic prostaglandin structural analogue used among other indications to increase eyelash growth. The aim of this prospective, open-label study was to evaluate the safety and efficacy of topical bimatoprost in the treatment of eyelash loss in alopecia areata totalis (AT) and universalis (AU). Study subjects applied ophthalmic bimatoprost (0.3 mg/ml) solution to the eyelid margins once nightly for at least 12 weeks (mean treatment period was 30.6 weeks). A total of 16 out of 17 subjects completed the study. Only the subjects with eyelashes present at baseline experienced an increase in eyelash length and thickness. No new eyelash regrowth was induced. In patients with AT and AU topical bimatoprost affected existing eyelashes, but failed to induce regrowth of new eyelashes.

The Impact of Long-Term Antibiotic Therapy of Cutaneous Adverse Reactions to EGFR Inhibitors in Colorectal Cancer Patients.

Colorectal cancer (CRC) is an important public health issue, in terms of incidence and mortality, with approximately 1.8 million new cases reported worldwide in 2018. Advancements in understanding pathophysiological key steps in CRC tumorigenesis have led to the development of new targeted therapies such as those based on epidermal growth factor receptor inhibitors (EGFR inhibitors). The cutaneous adverse reactions induced by EGFR inhibitors, particularly papulopustular rash, often require long-term antibiotic treatment with tetracycline agents (mostly minocycline and doxycycline). However, this raises several issues of concern: possible occurrence of gut dysbiosis in already vulnerable CRC patients, selection of highly antibiotic resistant and/or virulent clones, development of adverse reactions related to tetracyclines, interference of antibiotics with the response to oncologic therapy, with a negative impact on disease prognosis etc. In the context of scarce information regarding these issues and controversial opinions regarding the role of tetracyclines in patients under EGFR inhibitors, our aim was to perform a thorough literature review and discuss the main challenges raised by long-term use of tetracyclines in advanced CRC patients receiving this targeted therapy.

MSH6 mutation in a family affected by Muir-Torre syndrome.

Muir-Torre syndrome (MTS), a phenotypic variant of the more common hereditary nonpolyposis colorectal cancer syndrome, or Lynch syndrome, is an autosomal dominantly inherited condition that combines at least one cutaneous sebaceous neoplasm and at least one visceral malignancy. Most patients (~90%) with MTS carry mutations in the MSH2 gene; less than 10% of the cases are associated with a mutation MLH1 gene, and only 3 MTS patients with a pathogenic MSH6 mutation have been previously documented. We report a family affected with MTS in which 3 members (father and 2 sons) were found to harbor a missense mutation c.2633T>C (p.V878A) in exon 4 of the MSH6 gene.