Leukemia cutis (LC) refers to the infiltration of the skin by malignant leukemic cells—either neoplastic leukocytes or their precursors—resulting in clinically observable lesions. In contrast, leukemids are skin changes seen in leukemia but do not involve direct infiltration by leukemic cells. Histologically, LC shows diffuse infiltration of malignant leukocytes in the dermis, often clustering around blood vessels or sweat glands and sometimes penetrating collagen bundles.
Which Types of Leukemia Are Commonly Associated with LC?
LC has been documented in both myeloid and lymphoid leukemia types—including acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), prolymphocytic leukemia, and others. The highest incidence is seen in AML (especially monocytic and myelomonocytic subtypes), CLL, T-cell lineage leukemias, and congenital leukemias in children, where rates may reach 25–30 %. Overall, LC occurs in approximately 2–30 % of all leukemia cases, depending on leukemia subtype.
In the majority of cases—between 55 % and 77 %—LC appears after a diagnosis of systemic leukemia has already been established. In about 23 % to 44 % of cases, LC arises concurrently with the systemic diagnosis. Rarely (2 % to 3 %), LC precedes the detection of leukemia in blood or bone marrow, a scenario known as aleukemic LC.
What Are the Typical Clinical Presentations of LC?
Clinically, LC presents with a variety of morphologies:
•Most commonly as erythematous to violaceous papules or nodules (approximately 60 %) .
•Other presentations include infiltrated plaques, generalized eruptions, erythroderma, or ulcerated lesions.
•Lesions are often firm or rubbery, sometimes purpuric in thrombocytopenic patients.
•Atypical presentations may mimic ulcers, stasis dermatitis, guttate psoriasis, or figurate erythemas; lesions may appear at trauma sites or scars.
•Commonly affected areas include the trunk, limbs, face, scalp, and mucocutaneous surfaces .
•Lesions are typically non-tender and indurated, often pinkish or violaceous.
What Is Dermatoscopy?
Dermatoscopy is a non-invasive diagnostic technique that uses a dermatoscope to examine the skin more closely. It enhances the visualisation of skin structures and can help in diagnosing various skin conditions. The dermatoscope uses polarised light to illuminate the skin, allowing for a clearer view of the lesions.
The IBOOLO DE-4100 Pro features four light modes: Polarized Light & Amber Polarized Light & Non-Polarized Light & UV Light. Polarized light eliminates stray light, allowing clear visualization of the dermal layer. Amber polarized light enhances observation of lesion margins and is suitable for darker skin tones. Non-polarized light focuses on epidermal texture and surface details. 365nm UV light detects fungal lesions and hypopigmentation disorders.
How Can Dermatoscopy Aid in Differential Diagnosis?
Early detection of LC is crucial for several reasons. It allows for prompt initiation of appropriate treatment, which can improve the prognosis. The presence of LC is considered a predictor of poor prognosis, and most patients do not survive more than 12 months after its diagnosis. Early detection can also help in differentiating LC from other non-specific skin lesions, such as leukemids, which may occur in patients with leukaemia.
LC can be mistaken for other skin conditions with similar clinical presentations. Dermatoscopy can help differentiate LC by highlighting its unique features. For example, the polymorphic vascular pattern is considered among signs of malignancy in non-melanocytic skin tumors. In contrast, benign conditions may present with different vascular patterns or structures.
How Is Leukaemia Cutis Treated?
Leukaemia cutis (LC) does not have a single, skin-focused treatment because it reflects systemic disease. Management depends on the underlying type of leukaemia, the burden of skin involvement, and the overall health of the patient. Current evidence and clinical practice suggest the following approaches:
(1) Systemic therapy
The cornerstone of treatment is directed at the leukaemia itself. Chemotherapy, targeted therapy, or immunotherapy is chosen according to the leukaemia subtype (for example, acute myeloid leukaemia vs chronic lymphocytic leukaemia). In many patients, cutaneous lesions regress when remission of the systemic disease is achieved.
(2) Local or adjunctive therapy
If lesions persist, are symptomatic, or cause cosmetic or functional concerns, local measures may be added. These include radiotherapy, which can shrink resistant nodules or plaques, and, less commonly, topical chemotherapy or intralesional therapy in selected cases.
(3) Supportive care
Pain control, management of secondary infection, and skin protection are important components of care, especially in immunocompromised patients.
(4) Prognostic considerations
LC usually signals advanced disease and is associated with poorer outcomes. Treatment therefore is often palliative, aiming to improve quality of life and control symptoms, alongside systemic anti-leukaemia regimens.