Diagnostic exercise: Multiple skin nodules in a cat

Area of Science:

• Veterinary Dermatology
• Oncology
• Immunohistochemistry

Background:

• Dendritic cell histiocytosis is a rare neoplastic proliferation of cells of the dendritic cell lineage.
• Epitheliotropic forms involve the epidermis and dermis, presenting unique diagnostic challenges.

Observation:

• A 10-year-old domestic short-haired cat exhibited numerous, rapidly developing, ulcerated, and crusted dermal nodules across its body.
• Histological analysis revealed tightly packed polyhedral cells effacing dermal architecture with epidermal involvement.
• Cellular atypia, including multinucleation and bizarre nuclei, was noted.

Findings:

• The dermal mass demonstrated features consistent with epitheliotropic dendritic cell histiocytosis.
• CD18 immunocytochemical staining supported the diagnosis of this specific histiocytic neoplasm.
• Bacterial culture results were not detailed in the provided abstract.

Implications:

• This case highlights the clinical and histological presentation of feline progressive epitheliotropic dendritic cell histiocytosis.
• Accurate diagnosis relies on integrating histopathology and immunocytochemistry.
• Further research may elucidate treatment strategies for this rare feline cancer.