Histopathological features of human mpox: Report of two cases and review of the literature.

Human monkeypox is an emerging zoonosis with epidemic potential. Although it usually causes a mild disease, some patients are at risk for complications, including death. In face of the current outbreak of monkeypox in non-endemic areas, awareness is paramount to diagnose it timely, prompting an early break of the transmission chain. Histopathologic findings in vesiculopustular lesions of monkeypox are distinctive, consisting of ballooning and reticular degeneration of keratinocytes, necrosis, especially of the upper portions of the epithelium, multinucleation of keratinocytes, nuclear enlargement showing a "basophilic halo" around a "ground glass" eosinophilic center, the orthopoxvirus-specific cytoplasmic eosinophilic Guarnieri-type inclusions (in the pustular stage especially), and a dense mixed inflammatory cell infiltrate with prominent neutrophil exocytosis. The diagnosis of human monkeypox requires a high index of suspicion. In correlation with clinical information, histopathological findings allow for a presumptive diagnosis of monkeypox if polymerase chain reaction testing is not available. Both clinicians and pathologists can optimize diagnostic sensitivity, respectively, by considering the epidemiological context, sampling pustular lesions and providing data for clinicopathological correlation, and by intentionally searching the tell-tale eosinophilic inclusions in genital, anal and oral lesions with reticular and ballooning degenerescence.

Prurigiform Angiomatosis: Reactive Angioproliferation in the Skin and Vascular Endothelial Growth Factors.

BACKGROUND: Cutaneous benign angioproliferations can be diagnostically challenging and may mimic vascular tumors. Keratinocytes express vascular endothelial growth factors (VEGFs). We studied the angiogenic factor expression pattern in cutaneous lesions with a distinctive pattern of remarkable dermal angiomatosis underlying prurigo-like epidermal changes. METHODS: Cases were selected retrospectively from 2012 to 2018, and their VEGF staining pattern was compared with normal skin and other reactive skin conditions. RESULTS: Thirty-eight patients, median age 76 years, mostly men (74%), presented with asymptomatic patches or plaques, most commonly located on the buttocks (n = 17) and/or intergluteal fold (n = 12), often eliciting concern for neoplasia (n = 19). Microscopically, all cases featured a prominent proliferation of dilated capillaries and postcapillary venules, underneath epidermal changes resembling prurigo or lichen simplex chronicus. In one-third, a subepidermal lymphocytic infiltrate was present. Immunostaining with VEGF was positive in the upper 4/5 of the epidermis overlying the angioproliferation, in contrast with nonlesional skin, where VEGF positivity was limited to the stratum granulosum. Receptor VEGFR-2 was expressed in the endothelia of neovessels. CONCLUSIONS: We propose the term prurigiform angiomatosis for the morphological picture of prurigo/lichen simplex chronicus-like epidermal hyperplasia with prominent dermal angioproliferation. Mechanical injury and inflammation are the likely triggers of this reactive angiogenesis pattern, driven by epidermal VEGF expression.

[Skin Diseases in Africans]. / Dermatoses em Africanos.

Nowadays, due to the increasingly frequent migratory circuits in Europe and the increment of the migrant population in Portugal, mainly in the Lisbon metropolitan area, it is more and more common to find several dermatological conditions and disorders in Africans seen in our health care system. There are few studies on dermatoses in these populations. It is important to know the biologic and physiologic differences of black skin in order to understand both the pathophysiology and manifestations of dermatoses. The recognition of many of them represents a challenge to any clinician due to the specific characteristics of their skin. It is thus essential to know the different patterns and frequencies of skin diseases in Africans, in order to optimize the diagnosis, approach and treatment.

Atualmente, devido aos circuitos migratórios cada vez mais frequentes na Europa e consequente aumento da população migrante em Portugal, principalmente na área metropolitana de Lisboa, é cada vez mais comum depararmo-nos com diversas patologias dermatológicas nos indivíduos africanos que recorrem ao sistema de saúde. Existem poucos estudos sobre dermatoses nesta população.É importante conhecer as diferenças biológicas e fisiológicas da pele negra, de modo a compreender a fisiopatologia e a manifestação das dermatoses. O diagnóstico de muitas delas constitui um desafio para qualquer clínico devido às características especificas da sua pele. É essencial conhecer os diferentes padrões e frequências das doenças cutâneas em africanos, de modo a otimizar os seus diagnóstico, abordagem e tratamento.

FOSB immunoreactivity in endothelia of epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia).

BACKGROUND: Accurate distinction of epithelioid hemangioma (EH) from its malignant mimics is paramount but remains challenging due to its wide morphological spectrum and lack of objective molecular markers. FOSB oncogenic activation was recently identified as a key event in endothelial proliferation. We sought to investigate the FOSB staining pattern in EH with angiolymphoid hyperplasia with eosinophilia (EH-AHLE) morphology and to evaluate its value in differential diagnosis of epithelioid vascular tumors. METHODS: From the authors' files, 15 representative cases of EH-ALHE were selected and evaluated for their FOSB immunostaining pattern. Other vascular proliferations which can be morphological mimics were also tested: epithelioid hemangioendothelioma (EHE) (5 cases) and epithelioid angiosarcoma (EAS) (5 cases). RESULTS: All 15 cases of EH-ALHE showed strong and homogeneous FOSB nuclear expression in endothelial cells with ample cytoplasm and intracytoplasmic vacuoles. All cases of EHE and EAS lacked FOSB immunoreactivity or showed only incidental weak FOSB immunoreactivity in less than 5 nuclei per lesion. CONCLUSIONS: FOSB immunohistochemistry is sensitive in the diagnosis of EH-ALHE, and allows differentiation from its histological mimics. An immunohistochemical panel including not only pan-cytokeratin AE1/AE3 and endothelial markers, but also FOSB, helps in the diagnosis of epithelioid vascular tumors.