What's new in dermatopathology 2023: WHO 5th edition updates.

The 5th edition WHO Classification of Skin Tumors (2022) has introduced changes to nomenclature and diagnostics. Important differences are discussed below. Changes in each category of skin tumor have been detailed, with particular emphasis on meaningful advances in our understanding of the molecular pathogenesis of the skin's diverse tumor landscape.

Histopathologic Spectrum of Alopecias Seen in a Jamaican Setting.

ABSTRACT: Alopecia is common in Jamaican, primarily Afro-Caribbean patients. We performed a retrospective review examining the histopathologic alopecia diagnoses over ∼5 years. Requisition forms and pathology reports were assessed. Demographic/clinical/technical/diagnostic and pathologic findings of chronicity/severity data were recorded. Three hundred thirty-eight biopsies were included. The majority were 4 mm punches, grossed horizontally. The F:M ratio was 4.8:1, mean age = 42.7 years, and mean duration of alopecia = 5.1 years. Cicatricial alopecias (CAs) predominated over non-CAs (NCAs). The top 10 diagnoses were central centrifugal CA (21.9%), folliculitis decalvans (10.9%), multifactorial alopecias (10.1%), pattern hair loss (8%), lichen planopilaris (7.1%), alopecia areata (6.2%), discoid lupus erythematosus (6.2%), nonclassifiable lymphocytic scarring alopecias (5.6%), frontal fibrosing alopecia (5.3%), and nonspecific NCAs (5%). This contrasted with other richly pigmented populations where discoid lupus erythematosus predominates. Other interesting findings included relatively frequent folliculitis decalvans and lichen planus pigmentosus in 40.9% of frontal fibrosing alopecia cases. Scarring/nonscarring clinicopathologic congruence occurred in 83.4%.Regarding histopathologic features of severity/chronicity, CAs had markedly decreased hair counts. Perifollicular fibrosis affecting retained hairs occurred in 75% of CAs, moderate to severe in >50% of these. Approximately 50% of NCA samples demonstrated advanced miniaturization (T:V ratio <2:1). In our study, relatively young women with chronic hair loss and CA are most frequently biopsied. Central centrifugal CA is the most common diagnosis. Local features of chronic/severe disease are seen microscopically. Clinical impression of scarring/nonscarring correlates well with histopathology.