Leukemia and Lymphoma Cutis
Leukemia cutis (LC) and lymphoma cutis are skin lesions formed when malignant white cells (leukemic blasts) or malignant lymphocytes of myeloid or lymphoid lineage directly invade and multiply within the layers of the skin (dermis and subcutis).
Their appearance signals serious, progressing systemic disease:
- Leukemia cutis (LC): Most common in acute myeloid leukemia (AML), especially subtypes with a monocytic component (FAB AML-M4/M5, where it occurs in up to 10–30% of cases). LC also occurs in chronic myeloid leukemia (CML), chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL). It is a poor prognostic sign, pointing to a high risk of extramedullary relapse or blast crisis.
- Lymphoma cutis: Falls into two main groups:
- Primary cutaneous lymphoma: The disease starts in the skin, with no lymph node or internal organ involvement at diagnosis (most commonly cutaneous T-cell lymphoma, CTCL/mycosis fungoides, and cutaneous B-cell lymphoma, CBCL).
- Secondary lymphoma cutis: Lymphoma cells spread to the skin from lymph nodes or internal organs (for example, diffuse large B-cell lymphoma, DLBCL, or peripheral T-cell lymphoma, PTCL).
At the molecular level, malignant cells express skin-homing receptors such as cutaneous lymphocyte antigen (CLA), CCR4 and CCR10. Their interaction with molecules produced by skin endothelial cells and skin cells (E-selectin, CCL17, CCL27) lets malignant leukocytes and lymphocytes cross vessel walls, infiltrate and settle permanently in the dermis and subcutis.
At Haute-Derma, accurately diagnosing leukemia and lymphoma cutis can be lifesaving: it can reveal a flare of blood cancer early, before peripheral blood tests show clear changes.
Clinical Features and Patterns
Leukemia cutis and lymphoma cutis can look very different from one patient to the next and are easily mistaken for common benign skin conditions:
- How leukemia cutis (LC) presents:
- Infiltrated papules, nodules and plaques: Firm papules or nodules that are pink-red, plum-colored or reddish brown.
- “Blueberry muffin baby”: In newborns with congenital leukemia, numerous dark blue-purple papules and nodules are scattered over the body.
- Leukemic gingival infiltration: Swollen, enlarged gums that bleed easily and may become necrotic (typical of monocytic AML, M4/M5).
- Skin bleeding and purpura: Because of accompanying low platelet counts, LC lesions often come with bleeding under the skin, necrosis and ulceration.
- How lymphoma cutis presents:
- Mycosis fungoides (MF, cutaneous T-cell lymphoma): Typically progresses through three stages: patch stage → infiltrated plaque stage → ulcerating tumor stage.
- Sézary syndrome: Whole-body redness (erythroderma) with severe itching, thickened skin on the palms and soles, and malignant Sézary cells in the peripheral blood.
- Cutaneous B-cell lymphoma (CBCL): Smooth, shiny red-purple tumors, usually on the head, face, neck or back.
Telling Leukemia/Lymphoma Cutis Apart
| Leukemia / Lymphoma Cutis | Atopic Dermatitis | Plaque Psoriasis (Psoriasis Vulgaris) |
|---|---|---|
| Infiltration by malignant cells (blood / lymph nodes) | Allergic reaction to triggers, impaired skin barrier | T-cell–mediated autoimmune disease, epidermal hyperproliferation |
| Very firm, deep infiltration | Soft, rough from scratching, excoriated | Slightly firm plaques with white scale |
| Usually no scale (smooth, shiny or ulcerated surface) | Crusts, vesicles, scratch marks | Layered silvery-white scale, positive Auspitz sign |
| Poor response or rapid relapse | Responds well, itch settles quickly | Moderate to good response |
| Persistent low-grade fever, weight loss, night sweats, enlarged liver and spleen | No systemic symptoms | Usually none (except psoriatic arthritis) |
Diagnosis and Clinical Management at Haute-Derma
When a patient develops persistent, treatment-resistant, deep red-purple infiltrated papules or plaques, Haute-Derma follows a strict workup:
Dermoscopy and Hematologic History
- Digital dermoscopy: Looks for an orange-yellow background (typical of dense cellular infiltration), irregular linear or comma-like vessels, and the absence of typical scale.
- History: We ask about prior bone marrow disease, unexplained drops in red cells or platelets, prolonged fever, and swollen or painful lymph nodes.
Cosmetic Procedures Are Strictly Contraindicated
- No laser, peels, mesotherapy, microneedling or surgery: Cosmetic procedures of any kind (CO2 laser, IPL, RF, chemical peels, mesotherapy, thread lifts) must not be performed on suspicious lesions. Mechanical or thermal injury can trigger extensive necrosis and secondary infection and may seed malignant cells.
Skin Biopsy, Immunohistochemistry (IHC) and Molecular Diagnosis
Skin biopsy is the mandatory gold standard for identifying the exact malignant cell lineage:
- Histopathology (H&E): Shows dense infiltration of malignant cells around blood vessels and hair follicles in the dermis, often with a grenz zone (a band of uninvolved superficial dermis between the epidermis and the infiltrate).
- Immunohistochemistry (IHC) panel:
- Leukemia cutis: MPO (myeloperoxidase), CD68, CD117, CD33, CD43 (myeloid/monocytic AML); CD34 and TdT (acute blast leukemia).
- CTCL / T-cell lymphoma cutis: CD3, CD4, CD8, CD7 (loss of CD7 suggests malignancy), CD30 (points toward anaplastic large cell lymphoma).
- CBCL / B-cell lymphoma cutis: CD20, CD19, CD79a, PAX5, BCL2/BCL6.
- Gene rearrangement (clonality) testing: PCR analysis of T-cell receptor (TCR) or immunoglobulin heavy chain (IgH) gene rearrangements confirms whether the tumor cells are monoclonal.
Urgent Referral to Hematology and Oncology
As soon as the biopsy is suspicious or confirms the diagnosis:
- The patient is referred urgently to a hematology and blood transfusion hospital or a hemato-oncology department.
- Bone marrow aspiration/biopsy and flow cytometry of blood and marrow are performed to assess systemic involvement.
- Systemic treatment is coordinated: induction chemotherapy, tyrosine kinase inhibitors (TKIs), hematopoietic stem cell transplantation (HSCT) or total skin electron beam therapy (TSEBT, for CTCL).
