Dermatomyositis-like eruption associated with hydroxyurea therapy: a premalignant condition?

Dermatomyositis-like skin eruptions under hydroxyurea therapy conceal TP53-mutated atypical keratinocytes: A histopathologic and molecular pathologic case series

Hydroxyurea is an antimetabolite that inhibits DNA synthesis and is used as a treatment option in chronic myeloproliferative disorders. Rarely, "dermatomyositis (DM)-like" skin lesions are observed after long-term therapy. In this case series, five skin biopsies of four patients were evaluated by histology, immunohistochemistry, and next-generation sequencing of the TP53 gene locus. All biopsies showed focal basal pleomorphic keratinocytes and suprabasal aberrant p53 expression as well as sparse to severe vacuolar interface dermatitis. Histopathologically, "DM-like" skin lesions can be clearly distinguished from DM by marked subepidermal fibrosis, vascular proliferation, and the absence of dermal mucin deposits. In 75% of the specimens multiple, partly inactivating and/or pathogenic point mutations of TP53 were found in low frequencies. "DM-like" skin eruptions as a long-term consequence of hydroxyurea therapy are possibly not chemotherapy-associated benign toxic changes, but rather inflammatory reactions to complex keratinocyte alterations that clinically mimic the picture of DM. Synergistic mutagenic effects of hydroxyurea and sunlight might be responsible for this unique drug side effect and could provide a pathogenic link to the known increased risk of skin cancer in these patients.

Adverse Drug Reactions

Adverse events and adverse drug reactions are common in clinical practice. Side effects range from the common to the rare and may be confused with other mucocutaneous manifestations resulting from several medications to treat infections, other medical conditions, and in the clinical setting of oncologic treatment. The objective of this chapter to review current data on adverse drug reactions, here classified as (i) severe adverse drug reactions, (ii) uncomplicated cutaneous adverse drug reactions, and (iii) adverse drug reactions caused by chemotherapy drugs, particularly those cases whereby the dermatologist is requested to issue a report and asked to comment on the safety and viability of readministration of a specific drug. We describe aspects associated with these events, presenting a detailed analysis of each of them.

Dermatomyositis Associated with Myelofibrosis following Polycythemia Vera

Dermatomyositis (DM) is a unique inflammatory myopathy with clinical findings of proximal muscle weakness, characteristic rash, and elevated muscle enzymes. The association of DM and malignancy, most commonly adenocarcinoma, is well known. There have been few case reports of primary myelofibrosis associated with DM. We present the case of a 69-year-old male with a history of polycythemia vera (PV) who developed proximal muscle weakness, dysphagia, and rash. He was found to have elevated creatinine kinase and skin biopsy was consistent with DM. Due to persistent pancytopenia a bone marrow biopsy was performed and showed postpolycythemic myelofibrosis. To our knowledge, this is the first case reported of this unique association.