[Definitive diagnosis of intravascular large B-cell lymphoma by random skin biopsy].

A 69-year-old male was admitted to our hospital for high-grade-fever and body weight loss lasting for a few months. In a previous hospital, extensive laboratory examinations and imaging modalities had failed to establish the origin of the fever. On admission he showed mild anemia, and elevated LDH and CRP, together with a high sIL-2R level, suggesting a possibility of lymphoid malignancy without nodal or solid organ involvements, in particular, intravascular large B-cell lymphoma(IVLBCL). A bone marrow biopsy revealed no abnormal findings except minimal hemophagocytosis. A random skin biopsy was then performed, though no detectable skin lesion was seen. The histological results of the skin materials clearly showed a prominent intravascular large lymphoid cell proliferation with a phenotype of CD20+, CD79a+, CD3- and CD5- in the small vessels. On the basis of these findings, a diagnosis of IVLBCL was established and the patient was treated with(R-)CHOP regimen immediately, which resulted in complete remission following two courses of chemotherapy. Difficulties often arise in the diagnosis of IVLBCL when suspicious lesions suitable for biopsy are lacking. Random skin biopsy would therefore be a useful tool if less invasive measures fail.