What is the treatment approach for non-Hodgkin lymphoma (NHL) presenting with a skin rash?

Treatment Approach for Non-Hodgkin Lymphoma Presenting with Skin Rash

For non-Hodgkin lymphoma presenting with skin rash, the treatment approach should be determined by the specific subtype of cutaneous B-cell lymphoma, with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) being the standard treatment for aggressive subtypes like primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT). 1, 2

Diagnostic Evaluation

Before initiating treatment, a comprehensive diagnostic workup is essential:

• Skin biopsy of the rash for histopathology, immunohistochemistry, and molecular studies
• Complete blood count, blood film, lactate dehydrogenase (LDH) and ESR 3
• CT scan of chest, abdomen, and pelvis (with or without PET) 3
• Bone marrow biopsy (required for aggressive subtypes like PCLBCL, LT; optional for indolent types) 3

Treatment Based on NHL Subtype

1. Indolent Cutaneous B-cell Lymphomas (PCMZL and PCFCL)

For primary cutaneous marginal zone lymphoma (PCMZL) or primary cutaneous follicle center lymphoma (PCFCL):

• Solitary or localized lesions:

  • Surgical excision (98% complete response rate) 3
  • OR local radiotherapy (99% complete response rate) 3

• Multiple or widespread lesions:

  • Rituximab (systemic or intralesional) 3
  • Intralesional rituximab: 83-89% complete response rate 3
  • Systemic rituximab: 375 mg/m² IV weekly for 4 weeks 1, 2

• For antibiotic-responsive cases (especially PCMZL associated with Borrelia infection):

  • Trial of appropriate antibiotics (43% complete response rate) 3

2. Aggressive Cutaneous B-cell Lymphoma (PCLBCL, LT)

For primary cutaneous diffuse large B-cell lymphoma, leg type:

• R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) is the standard treatment 3, 1, 2

  • 92% complete response rate with only 9% relapse rate 3
  • 6-8 cycles given every 21 days 1

• For localized disease:

  • Consider adding local radiotherapy to R-CHOP 3

• For elderly or frail patients:

  • Consider R-miniCHOP (reduced-dose regimen) 1

Treatment Response Assessment

• Repeat imaging after 3-4 cycles and at completion of treatment 1
• Include PET scans in response assessment if positive at baseline 1
• Repeat bone marrow biopsy at end of treatment if initially involved 1

Follow-up Recommendations

• History and physical examination every 3 months for 1-2 years, every 6 months for 2-3 more years, then annually 1
• Blood count and LDH at 3,6,12, and 24 months 1
• Radiological examinations at 6,12, and 24 months after treatment completion 1

Important Considerations and Pitfalls

1. Misdiagnosis risk: Skin rash in NHL can be misdiagnosed as dermatologic conditions, delaying proper treatment 4, 5. Always consider lymphoma in persistent, unexplained rashes.

2. Subtype determination is crucial: Treatment approach differs significantly between indolent (PCMZL, PCFCL) and aggressive (PCLBCL, LT) subtypes 3.

3. Avoid unnecessary chemotherapy: Indolent cutaneous B-cell lymphomas should not be treated primarily with systemic chemotherapy despite having a diffuse infiltration pattern 3.

4. Relapse management: Despite high initial response rates, relapses are common (40-58%) but often remain confined to the skin and don't affect survival 3.

5. Bone marrow examination: While optional in PCMZL, bone marrow examination should be considered essential in PCFCL as it may be the only evidence of extracutaneous disease in 11% of patients 3.