Primary cutaneous CD30+ anaplastic large-cell lymphomas mimicking keratoacanthomas

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Primary cutaneous anaplastic large cell lymphoma (ALCL) is a CD30+ T-cell lymphoma.
• ALCL can present with challenging clinical and histological features.
• Keratoacanthoma (KA)-like epithelial hyperplasia is a rare presentation of ALCL.

Observation:

• Two cases of CD30+ ALCL with KA-like tumors on the eyelid and nose were observed.
• Histological examination revealed atypical lymphoid cells obscured by dense eosinophilic and neutrophilic infiltrates.
• One case exhibited features mimicking KA with significant tissue eosinophilia and neutrophilia.

Findings:

• Diagnosis of ALCL can be difficult when it presents as a KA-like lesion.
• The dense inflammatory infiltrate can mask the underlying atypical lymphoid cells.
• Misdiagnosis as squamous cell carcinoma or KA is a potential pitfall.

Implications:

• Increased awareness of ALCL presenting as KA-like lesions is crucial for accurate diagnosis.
• Careful histological evaluation, including immunohistochemistry for CD30, is essential.
• Prompt diagnosis and treatment of cutaneous ALCL can improve patient outcomes.