Clinical, histopathologic, immunohistochemical, and electron microscopic findings in cutaneous monkeypox: A multicenter retrospective case series in Spain.

BACKGROUND: The worldwide outbreak of monkeypox has evidenced the usefulness of the dermatologic manifestations for its diagnosis. OBJECTIVE: To describe the histopathologic and immunohistochemical findings of monkeypox cutaneous lesions. METHODS: This is a retrospective histopathologic and immunohistochemical study of 20 patients with positive Monkeypox virus DNA polymerase chain reaction and immunohistochemical positivity for Vaccinia virus in cutaneous lesions. Four cases were also examined by electron microscopy. RESULTS: The most characteristic histopathologic findings consisted of full-thickness epidermal necrosis with hyperplasia and keratinocytic ballooning at the edges. In some cases, the outer root sheath of the hair follicle and the sebaceous gland epithelium were affected. Intraepithelial cytoplasmic inclusion bodies and scattered multinucleated keratinocytes were occasionally found. Immunohistochemically, strong positivity with anti-Vaccinia virus antibody was seen in the cytoplasm of ballooned keratinocytes. Electron microscopy study demonstrated numerous viral particles of monkeypox in affected keratinocytes. LIMITATIONS: Small sample size. Electron microscopic study was only performed in 4 cases. CONCLUSION: Epidermal necrosis and keratinocytic ballooning are the most constant histopathologic findings. Immunohistochemical positivity for Vaccinia virus was mostly detected in the cytoplasm of the ballooned keratinocytes. These findings support the usefulness of histopathologic and immunohistochemical studies of cutaneous lesions for diagnosis of monkeypox.

Histopathology of Dermatologic Complications of Tattoos.

ABSTRACT: Tattoos are characterized by the introduction of exogenous pigments into the dermis. Tattoos usually serve cosmetic purposes, although they may have other causes, such as traumatic pigment implants in accidents or medical-related tattoos in the context of radiotherapy. Dermatologic adverse reactions are relatively uncommon, and they include infections, immune-mediated reactions, cutaneous lesions secondary to the Koebner phenomenon, exacerbation of preexisting dermatosis, benign and malignant neoplasms, and a miscellaneous group of dermatologic conditions that may appear in a preexisting tattoo. The aim of this study is to review the types of histopathologic reactions that may appear in a preexisting permanent tattoo.

Immunophenotypic Differences in Tumor-Infiltrating Lymphocytes and Neovascularization Between Primary Cutaneous Melanoma With and Without Metastasis: An Immunohistochemical Study of 80 Cases.

ABSTRACT: The prognostic implications of the immunophenotype of the tumor-infiltrating lymphocytes (TILs) in primary cutaneous melanoma are well known. In recent years, the study of this immunophenotype has also resulted in immunotherapeutic consequences. The aims of this study were to characterize the subpopulations of TILs in primary cutaneous melanoma, in cases with and without metastasis, as well as the neovascularization associated with the primary neoplasm, and its influence on the development of metastasis. To this end, the immunophenotype of TILs and the neovascularization of 80 patients with primary cutaneous melanoma (40 each with metastatic and non-metastatic melanoma) were analyzed by immunohistochemistry for CD3, CD4, CD8, FOXP3, PD-1, CD31, and D2-40 antibodies. We found that higher frequencies of TILs with brisk pattern, and CD4+, CD8+, and CD20+ cells in TILs, and a lower frequency of CD31+ vessels were histopathological features associated with better prognosis in primary cutaneous melanoma. Our results support the notion that the immunohistochemical study of TILs and neovascularization in primary cutaneous melanoma may be helpful tools for identifying patients at increased risk of metastasis development.