Enfortumab vedotin-induced cutaneous eruption: Ring mitotic figures as a distinctive histopathologic feature.

Enfortumab vedotin (EV), a nectin-4-binding agent that affects microtubules, has become standard therapy for advanced urothelial carcinoma. The agent, now given in combination with pembrolizumab, frequently induces cutaneous reactions. Here, we report a severe EV-induced cutaneous eruption. A 58-year-old woman with metastatic urothelial carcinoma developed a rash after receiving simultaneous first doses of EV and pembrolizumab. The eruption began on the flank and spread to involve her trunk and extremities with prominent involvement of folds, including the axillae and medial thighs. Skin biopsy revealed extensive vacuolar alteration of the basal epidermis and numerous epidermal keratinocytic mitotic figures, often suprabasilar, including ring and "starburst" forms. The findings supported a diagnosis of EV-induced eruption. With EV cessation and systemic corticosteroids, the rash resolved over a few weeks. Pembrolizumab was restarted as monotherapy, and the patient's cancer showed a significant radiographic treatment response at 3 months. An emerging literature of small series and case reports, largely from oncologic literature, presents the histopathology of EV-induced cutaneous eruption as a vacuolar interface dermatitis with the inconsistently reported feature of arrested mitotic figures. This case study demonstrates distinctive clinical and histopathologic features of EV-induced eruption, which may inform dermatologic and oncologic management.

Continuous access to snacks from weaning onwards in female rats causes weight gain, insulin insensitivity, and sustained leptin resistance in adulthood.

A large part of the daily intake of children in the U.S. consists of snacks, with the average child consuming three snacks per day. Despite this, little research has been conducted to determine the metabolic and behavioral effects of snacking. Using a developing female rat model, our studies aimed to determine the effects of snacking during development before the protective effects of estrogen on weight gain would be relevant. Additionally, to determine if snack composition is important, we created one healthy and one unhealthy snacking group provided with chow and three snacks each in addition to a chow-only group. We found that both snacking groups experienced increased weight gain, elevated abdominal fat pad mass, prolonged leptin resistance into adulthood, and insulin insensitivity that was not observed in their non-snacking counterparts. These physiological differences were measured despite both snacking groups having a similar caloric intake as the chow-only group throughout the study. In addition to physiological changes, both snacking groups showed a preference for snacks over chow and ate more often during the inactive light phase than typical for rats, with the unhealthy snacking group presenting this behavioral change earlier than the healthy snacking group. Our results suggest that constant access to palatable snacks, which is often the case for children in western countries, alters feeding behaviors in relation to food choice and time of day when eating occurs. Snacking during development seemed to promote signs of metabolic syndrome in adulthood even when excess caloric intake was not observed. Our work further suggests that development is a vulnerable time for palatable snack presentation when prepubertal females lack the protective effects of estrogen and exhibit reduced leptin feedback on food intake. Thus snacking from weaning onward could be a contributor to the current childhood obesity crisis.