Nuclear and cytoplasmic features in the diagnosis of Clark's nevi.

BACKGROUND: Interpretation of Clark's nevi has generated debate over the years; although criteria have been proposed for grading morphological features of melanocytes, there is still confusion and variability in the assessment of these lesions. METHODS: This is a retrospective observational study conducted on 100 Clark's nevi and 84 melanomas. A single expert dermatopathologist evaluated all blinded and randomized photomicrographs of both the Clark's nevi and melanomas for the presence of 14 cytologic features. Subsequently, a multivariate model was used to obtain sensitivity and specificity. RESULTS: Clark's nevi showed a significantly higher frequency of absent-or-inconspicuous nucleoli over melanoma, whereas mitotic figures, pleomorphism, notching, multiple nucleoli, peppered moth nuclear pattern, flattened adjacent nuclei, prominent nucleoli and vesicular nucleus with rounded nucleoli were found significantly higher in frequency in melanomas. CONCLUSION: Our data suggest that nuclear alterations are of value in the differentiation of atypical nevi from melanoma.

Calcinosis cutis dermatologic toxicity associated with fibroblast growth factor receptor inhibitor for the treatment of Wilms tumor.

Small-molecule inhibitors (nibs) have revolutionized cancer therapy with the emergence of clinically efficacious treatment for advanced-stage malignancies. Fibroblast growth factor receptor (FGFR) inhibitors have shown therapeutic efficacy in malignancies with molecular-genetic alterations in the FGFR/fibroblast growth factor pathway. In a phase 1 clinical trial, erdafitinib, a pan FGFR inhibitor, was well tolerated with a manageable toxicity profile. Hyperphosphatemia was a frequent adverse event in patients treated with erdafitinib; however, no serious complications were observed with this therapy. Here, we report the development of calcinosis cutis dermatologic toxicity in a patient with hyperphosphatemia while treated with a novel selective FGFR inhibitor, INCB 54828-101. Awareness of this form of dermatologic toxicity from an FGFR inhibitor will be important for close monitoring of serum levels of phosphate, FGF23, vitamin D, and calcitriol, the management of adverse serum chemistry with chelators, and treatment decisions to either reduce dose or withhold FGFR inhibitor.