Supplementary Material for: Limited Role of Random Skin Biopsy in the Diagnosis of Intravascular Lymphoma in Adult Patients with Hemophagocytic Lymphohistiocytosis

<strong><em>Background/Aims:</em></strong> This study examined the role of random normal skin biopsy in the diagnosis of intravascular lymphoma (IVL) in adult Western patients with clinically diagnosed hemophagocytic lymphohistiocytosis (HLH). <b><i>Methods:</i></b> In a retrospective chart review study, we analyzed a total of 59 skin biopsies that were performed to diagnose IVL in 21 adult patients with HLH seen at Stanford Hospital between 2004 and 2016. <b><i>Results:</i></b> Out of the 59 skin biopsies, 42 were taken from clinically normal-appearing skin and 17 from clinically abnormal-appearing skin. None of the 59 biopsies revealed a diagnosis of primary or metastatic malignancy, regardless of the malignancy history, clinical presentation, and biopsy and histopathologic characteristics. A review of 8 positive IVL cases at Stanford Hospital including 1 case associated with HLH showed 1 positive diagnosis by a targeted skin biopsy and other positive diagnoses by bone marrow (<i>n</i> = 4), lung (<i>n</i> = 2), brain (<i>n</i> = 2), muscle (<i>n</i> = 1), and nerve (<i>n</i> = 1). <b><i>Conclusion:</i></b> Random skin biopsies have a limited role in diagnosing IVL in adult patients with HLH, in the setting of a single academic institution in the USA. A review of the literature emphasizes the role of a full body skin exam with a selective skin biopsy in these patients.