Pityriasis Lichenoides-Like Mycosis Fungoides: A Case Report

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma (CTCL).
• Pityriasis lichenoides-like mycosis fungoides (PL-like MF) is a rare subtype characterized by specific clinical and histological features.
• CD8+ CTCL encompasses both aggressive and indolent variants, necessitating accurate diagnosis for prognostic assessment.

Observation:

• A 64-year-old male presented with recurrent psoriasiform papules and mild scaling on the trunk and extremities.
• Clinical presentation mimicked pityriasis lichenoides (PL).
• Skin biopsy revealed histological findings consistent with CD8+ cutaneous T-cell lymphoma (CTCL).

Findings:

• The patient's presentation combined clinical features of pityriasis lichenoides with histological evidence of CD8+ mycosis fungoides.
• Differential diagnoses included pityriasis lichenoides, lymphomatoid papulosis, and PL-like MF.
• The case highlights a rare, indolent variant of CD8+ CTCL.

Implications:

• Accurate identification of PL-like MF is crucial for differentiating it from more aggressive CD8+ CTCL subtypes.
• Distinguishing indolent from aggressive variants allows for appropriate patient counseling regarding prognosis and management.
• This recognition aids clinicians in providing tailored care for patients with CD8+ cutaneous T-cell lymphoma.