Comparing Follicular Extension Between Low-Grade and High-Grade Dysplastic Nevi.

ABSTRACT: Dysplastic nevi are an important subset of melanocytic nevi with atypical clinical, histopathologic, as well as genomic features compared with common acquired nevi. Dysplastic nevi are characterized histologically by both cytologic atypia and architectural disorder. The established criteria for cytologic atypia used to distinguish between low-grade and high-grade dysplastic nevi are often subjective, although there is a dearth of more objective, reproducible features of architectural disorder (eg, pagetoid scatter) that have been validated to differentiate between low-grade and high-grade dysplastic nevi. In this study, we sought to determine whether the presence and degree of follicular extension differ between low-grade and high-grade dysplastic nevi. We retrospectively examined the histopathologic features of 90 dysplastic nevi: 60 cases of low-grade dysplastic nevi (average age of 47.2 ± 18.1 years; 62.7% female) and 30 cases of high-grade dysplastic nevi (average age of 47.4 ± 19.8 years; 60.0% female). After examination, 50% of the cases of dysplastic nevi (n = 45) had hair follicles within the lesion, for which the presence and degree of follicular extension was then determined. Low-grade and high-grade dysplastic nevi do not differ significantly regarding the presence of follicular extension, average depth of follicular extension, and confluence of nevus cells along the follicular epithelium. Both low-grade and high-grade dysplastic nevi in our study demonstrated follicular extension that was superficial, that is, above the level of isthmus of hair follicles (insertion of sebaceous gland into hair follicle). Future studies are warranted to confirm these preliminary findings.

Acquired Reactive Perforating Collagenosis Occurring in Association With Nonred Ink Tattoo.

ABSTRACT: Perforating dermatosis is a group of skin conditions in which there is transdermal elimination of collagen, elastic fibers, or other dermal connective tissue. Perforating dermatosis can be genetic or acquired, known as acquired perforating dermatosis (APD). When collagen is the primary extruded material in acquired cases, the disease is designated as acquired reactive perforating collagenosis (RPC). We report a case of acquired RPC occurring in a new tattoo. One week after having a new tattoo placed on the left forearm, a 38-year-old gentleman presented to the emergency room with pruritic, crusted plaques and erosions in the regions of red and green inks of the tattoo. Histopathologic examination of the biopsy revealed an ulceration with transepidermal elimination of collagen bundles accompanied by basophilic debris, scattered dermal tattoo pigment, and a superficial to deep perivascular lymphohistiocytic infiltrate with scattered neutrophils and eosinophils. There have been 2 reported cases of tattoo-associated RPC, both in association with red tattoo ink. This present case is the first reported APD to occur in association with nonred tattoo ink. This case reaffirms the conclusions of others in recognizing APD as a potential tattoo-associated complication.