Palmar Petechiae in a Patient Receiving Ibrutinib for Chronic Lymphocytic Leukemia: A Case Report

Ibrutinib is an oral Bruton tyrosine kinase (BTK) inhibitor widely used in the treatment of chronic lymphocytic leukemia (CLL) and other B-cell malignancies. Bleeding-related adverse effects are well recognized with this therapy and are thought to result from impaired platelet signaling. Cutaneous findings including petechiae and purpura have been described clinically, though the histopathologic features of these eruptions are less frequently discussed. We report a case of a 64-year-old man with CLL receiving long-term ibrutinib therapy who presented with numerous asymptomatic petechial hemorrhages on the palms and a few similar lesions on the soles. The lesions had developed gradually over several months and were increasing in number. Physical examination revealed multiple pinpoint, non-blanching petechial hemorrhages scattered across the bilateral palms. Given the patient's oncologic history and the acral distribution of the lesions, the differential diagnosis included petechiae secondary to ibrutinib therapy, leukocytoclastic vasculitis, embolic phenomena, and angioinvasive infection. A punch biopsy of the left palm demonstrated intraepidermal collections of extravasated erythrocytes, consistent with petechiae, with only minimal superficial inflammation and no evidence of vasculitis or infection. These collections were most prominent in the lower epidermis near the dermoepidermal junction. Our findings expand the limited histopathologic literature on BTK inhibitor-associated acral petechiae and warrant further characterization in additional cases.