ALK-Negative Systemic Anaplastic Large Cell Lymphoma With Multifocal Cutaneous Involvement Responding to Brentuximab...

Area of Science:

• Oncology
• Dermatology
• Pathology

Background:

• Systemic anaplastic large cell lymphoma (ALCL) with cutaneous involvement often presents with non-specific skin lesions, mimicking other malignancies and potentially delaying diagnosis and treatment.
• Accurate diagnosis is crucial for effective management, especially in cases with atypical presentations or initial misinterpretations.

Purpose of the Study:

• To present a case of ALK-negative systemic anaplastic large cell lymphoma with extensive cutaneous involvement that was initially misdiagnosed.
• To emphasize the diagnostic challenges, the importance of comprehensive histopathological evaluation including immunohistochemistry, and the efficacy of CD30-directed therapy in managing cutaneous manifestations of systemic ALCL.

Main Methods:

• A case report of a 71-year-old woman with a history of misdiagnosed skin lesions.
• Histopathological examination and immunohistochemistry (CD30, CD3, CD45, ALK, EMA) of biopsy specimens from skin lesions and recurrent masses.
• Clinical staging to determine the extent of systemic disease.
• Treatment with a chemotherapy regimen including brentuximab vedotin.

Main Results:

• Initial biopsy was misread as a spindle cell tumor, leading to delayed diagnosis of ALK-negative systemic ALCL with cutaneous involvement.
• Repeat biopsies confirmed a dermal-subcutaneous infiltrate of large atypical lymphocytes consistent with ALCL.
• Staging revealed stage IV disease with extranodal metastases.
• Treatment with brentuximab vedotin resulted in marked improvement of cutaneous lesions within 5 cycles.

Conclusions:

• ALK-negative systemic ALCL with cutaneous involvement can present insidiously and mimic other skin conditions.
• Thorough histopathological sampling, focused immunohistochemistry, and comprehensive staging are essential for accurate diagnosis.
• CD30-directed therapy, such as brentuximab vedotin, can achieve rapid and significant responses in the cutaneous manifestations of systemic ALCL.