Generalized early inflammatory morphea mimicking interstitial T-cell lymphoma: A diagnostic pitfall

Area of Science:

• Dermatopathology
• Immunohistochemistry
• Cutaneous Lymphoma

Background:

• Early generalized morphea can present with inflammatory skin lesions that mimic other conditions.
• Distinguishing early morphea from mycosis fungoides is crucial for appropriate patient management.

Observation:

• A 63-year-old female presented with asymptomatic skin patches resembling mycosis fungoides.
• Initial skin biopsies showed lymphoid infiltration without sclerosis, with concerning immunohistochemical findings (CD5/CD7 loss) and positive HTLV-1 antibodies, suggesting mycosis fungoides or T-cell leukemia.
• The patient later developed indurated plaques consistent with morphea.

Findings:

• Initial histopathology of inflammatory morphea may lack characteristic sclerosis and show features that can be mistaken for mycosis fungoides.
• Immunohistochemical findings, including antigen loss, can complicate the diagnosis.
• A delayed diagnosis of morphea occurred due to initial misinterpretation of biopsy findings.

Implications:

• This case highlights diagnostic pitfalls in differentiating early inflammatory morphea from mycosis fungoides.
• Clinicians and pathologists must consider the potential for evolving histopathological features in diagnosing morphea.
• Awareness of these diagnostic challenges can prevent misdiagnosis and ensure timely, appropriate treatment.