DISCUSSION
Patients with underlying hematologic malignancies can present with a diversity of non-specific reactive skin lesions or specific infiltrates.3 Leukemia cutis is a cutaneous infiltration of neoplastic leukocytes which has multiple clinical presentations including erythematous papules, nodules, plaques, bullae, noduloulcerative lesions, and even erythroderma.3 The lesions are often firm or/and hemorrhagic lesions.The most common locations are face, head, neck, and trunk.3
In addition to usual typical skin manifestations, the recorded unusual manifestations of leukemia cutis were summarized in retrospective study in 2021 by Yung-WeiChang which included leonine faces, figurate cutaneous lesions, fingertip hypertrophy, erythema nodosum, guttate psoriasis, chronic paronychia, leukemic vasculitis, and Sister Mary Joseph’s nodule.4
Our patient was complaining of hyperpigmneted patches on the face and upper trunk from six months before presenting to our clinic and unfortunately the patches were treated as skin pigmentation.
Involvement of skin can be seen in any leukemia subtype, but most commonly seen in acute myeloid leukemia (AML) with monocytic or myelomonocytic and chronic lymphocytic leukemia (CLL), and rarely in chronic myeloid leukemia (CML) which can be indicative for blast transformation.5
The diagnosis of leukemia cutis is usually achieved by histological study and immunophenotyping.6 Histological findings vary according to the type of leukemia, and most commonly present as perivascular and periadnexal dermal infiltrate.6,7Additional occasional finding includes stromal fibrosis, ulceration, dermal vessel thrombus, and subcutaneous (7).
Currently, there is no specific treatment for leukemia cutis, and cutaneous eruption usually resolves following treatment of underlying leukemia (8).
To our knowledge, hyperpigmented patches secondary to leukemia cutis is rarely described in the literature. Dermatologists could have an important role in diagnosis of internal diseases including leukemia. Postponing the diagnosis of leukemia cutis means delaying the diagnosis of the underlying leukemia which lead to poor prognosis. Early diagnosis of leukemia cutis can lead to better outcomes and may direct to an underlying malignancy.