Discussion
MF is characterized by malignant proliferation of T cells with epidermotropism in the skin.1 The diagnosis of MF is often delayed by many years from the initial appearance of skin lesions due to its indolent course and diagnostic difficulties as in our patient. In the early stages of disease, it can mimic common skin conditions like chronic eczema, psoriasis and atopic dermatitis.1,2
The factors predisposing for higher rates of certain malignancy in MF is not known, however an inherent potential of disease itself or therapy utilized for treatment could be the potential cause.3Viral infections, genetic factors, and environmental exposures implicated in carcinogenesis might be the common mechanism linking the onset of MF with increased risk for a second malignancy.4 Furthermore, altered T-cell activation in MF might contribute to develop secondary lymphoid malignancy, as it is evident that a subset of highly immunosuppressive regulatory T cells emerging from the infiltrating malignant T cells increases the risk of severe infections and malignancy in MF as in our case.3,4
Diagnosis is difficult especially in the early stages, but it is made through clinical examination and is confirmed by a skin biopsy, immunohistochemistry and staged appropriately. Histologically, early MF are characterized by epidermotropism, atypical lymphocytes with cerebriform nuclei, Pautrier’s microabscesses and basal alignment of neoplastic lymphocytes as seen in our case. In immunohistochemistry, MF cells are positive for CD2, CD3, CD4, CD5 and negative for CD20 as reported in our case.3,5 Management is based on disease stage and includes skin-directed therapies, systemic therapies and allogenic stem cell transplantation.1,2
MF is a clinical diagnosis; however, is easily misdiagnosed at an early stage due to its nonspecific clinical features and lack of awareness, warranting a high index of clinical suspicion. MF should be suspected in patients with underlying malignancies and patients with MF are at high risk for developing secondary malignancies which should be screened for and the other way around.