A Longstanding, Persistent and Recurrent Case of Cryptogenic Panniculitis

Area of Science:

• Dermatology
• Oncology
• Immunology

Background:

• Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare cutaneous T-cell lymphoma.
• Histologic overlap with other panniculitides like lupus profundus and traumatic panniculitis is common.
• Accurate diagnosis is essential for appropriate patient management.

Observation:

• A 54-year-old woman with a prior SPTCL diagnosis experienced new subcutaneous nodules.
• Initial diagnosis was based on scalp biopsy and CD8+ T-cell infiltrate.
• Repeat biopsy showed a different panniculitis with eosinophils, histiocytes, and mixed T-cell populations.

Findings:

• Immunohistochemistry revealed mixed CD4+, CD8+, and CD7+ lymphocytes and CD68+ histiocytes in the new lesions.
• T-cell gene rearrangement studies on the new lesions failed to demonstrate clonality.
• The findings suggest a co-existing or alternative panniculitis rather than a progression of SPTCL.

Implications:

• SPTCL patients can develop other forms of panniculitis, necessitating re-evaluation.
• Complete histologic, immunohistochemistry, and molecular analyses are vital for correct diagnosis.
• This case highlights the importance of thorough workups to differentiate SPTCL from other panniculitides.