Histopathologic Findings of Evolving Mpox Lesions

Area of Science:

• Dermatopathology
• Virology
• Infectious Diseases

Background:

• The 2022 mpox virus outbreak presented with atypical clinical manifestations.
• Histopathological descriptions of mpox lesions during this outbreak are limited.

Observation:

• Two cases of mpox (monkeypox) virus infection are presented with distinct histopathological findings.
• Case 1: Umbilicated papules showed epidermal acanthosis, keratinocyte pallor, ballooning degeneration, necrosis, and neutrophilic epitheliotropism.
• Case 2: A perianal mass exhibited ulceration, keratinocyte changes, and multinucleated keratinocytes, a novel finding described as mpox pseudotumor.

Findings:

• Detailed histopathology of evolving mpox lesions is described, contributing to the sparse literature on the 2022 outbreak.
• Key findings include epidermal changes, keratinocyte necrosis, and specific inflammatory infiltrates.
• The identification of a perianal mpox pseudotumor is a novel contribution.

Implications:

• These histopathological findings aid in the diagnosis of mpox, especially in atypical presentations.
• Understanding lesion evolution through histopathology is crucial for accurate diagnosis and patient management.
• This research highlights the importance of integrating clinical, laboratory, and histopathological data for mpox diagnosis.