Cutaneous side-effects are found in 100% of patients treated with EGFRIs for more than 6 months and have a significant effect on patients' QoL. The clinical spectrum of skin manifestation varies over time. As the use of EGFRIs rapidly increases, it is critical for us to improve our knowledge in the understanding and managment of these skin manifestations.

YAP1-NUTM1 fusion transcripts have been recently reported in poroma and porocarcinoma. NUTM1 translocation can be screened by nuclear protein in testis (NUT) immunohistochemistry in various malignancies, but its diagnostic performance has not been thoroughly validated on a large cohort of cutaneous epithelial neoplasms. We have evaluated NUT immunohistochemical expression in a large cohort encompassing 835 cases of various cutaneous epidermal or adnexal epithelial neoplasms. NUT expression was specific to eccrine poromas and porocarcinoma, with 32% of cases showing NUT expression. All other cutaneous tumors tested lacked NUT expression, including mimickers such as seborrheic keratosis, Bowen disease, basal cell carcinoma, squamous cell carcinoma, Merkel cell carcinoma, nodular hidradenoma, and all other adnexal tumors tested. Remarkably, NUT expression was more frequent in a distinct morphologic subgroup. Indeed, 93% of poroid hidradenoma (dermal/subcutaneous nodular poroma, 13/14) and 80% of poroid hidradenocarcinoma cases (malignant poroid hidradenoma, 4/5) showed NUT expression, in contrast to 17% and 11% of classic poroma (4/23) and porocarcinoma cases (4/35), respectively. RNA sequencing of 12 NUT-positive neoplasms further confirmed the presence of a YAP1-NUTM1 fusion transcript in all cases, and also an EMC7-NUTM1 gene fusion in a single case. In the setting of a cutaneous adnexal neoplasm, nuclear expression of NUT accurately and specifically diagnosed a specific subgroup of benign and malignant poroid tumors, all associated with a NUTM1 fusion, which frequently harbored a poroid hidradenoma morphology.

Background: Tufted angioma (TA) is a rare benign vascular tumor that mostly appears during infancy or early childhood. Histologic tufts of capillaries infiltrating the whole dermis in a "cannonball" distribution pattern associated with dilated lymphatic vessels are characteristic of the disease and confirm the diagnosis. Few case series of TA have been published, and the morphologic structure and evolution of TA seem to vary. Observations:We describe the largest series to date of childhood TA, comprising 13 cases. All children developed lesions within the first year of life; 7 cases were congenital. We found a clear male predominance (9 of 13 children). Presentation was a nascent or florid tumor, usually a dusky red to violaceous plaque, that was indurated, firm, and sometimes associated with hyperhidrosis or hypertrichosis. Locations of the lesions included limbs, abdomen, and genitalia. Five children had spontaneous regression, 5 children had Kasabach-Merritt syndrome, and 1 child had a lesion that stabilized. Two children with painful TA had chronic coagulopathy without thrombocytopenia that was controlled by ticlopidine hydrochloride and aspirin. Conclusions:The following 3 clinical patterns could be distinguished: TA without complications, TA complicated by Kasabach-Merritt syndrome, and TA without thrombocytopenia but with chronic coagulopathy. To our knowledge, this study is the first to describe the third pattern. Because of the aggressive nature of Kasabach-Merritt syndrome, it is essential to obtain a complete blood cell count when evaluating a child with TA.

Background: Series regarding the clinical characteristics of molluscum contagiosum (MC) are retrospective and concern small defined populations seen in a hospital setting. Methods: We prospectively studied patients under 15 years of age with MC seen in 25 private dermatology practices in the greater Paris area during 1 year. Results: Six hundred fifty patients were included. The mean age was 6 years. Of the patients, 30.5% had had MC in the past, 53% had 5–20 MC, 43% had a history of atopic dermatitis (AD), 5% were using topical steroids, 25.5% had coexistent AD, 13% had giant MC (>5 mm), 21% had inflammatory MC, and 19% had MC surrounded by eczema. Bathing with siblings was associated with a higher number of MC. A history of AD was associated with the presence of MC surrounded by eczema. The use of topical steroids was associated with a higher risk of relapse. There was no relation between environmental factors (MC in surrounding people, going to the swimming pool, sports practice) and the number of lesions or between environmental factors and the number of recurrences. Conclusion: Atypical lesions are frequent. Bathing with siblings is associated with a higher number of MC. Topical steroid use increases the risk of relapses. AD prevalence is higher than in the general population.

No abstract