LAUSR

A 37yearold man with a longstanding history of intravenous drug abuse presented with a pathological fracture of the right hip and isolated anaemia (haemoglobin concentration 88 g/l). Magnetic resonance imaging of the hip showed multifocal illdefined bone lesions. A peripheral blood film showed increased vacuolated monocytes (0.88 × 109/l) whilst red cells showed anisocytosis and mild polychromasia. An attempted bone marrow aspiration resulted in a dry tap and touch imprints were made from the core biopsy specimen. These showed numerous macrophages with voluminous foamy cytoplasm, isolated and in clumps. They had a mature chromatin pattern with multinucleate forms being observed (top left, ×50 objective). No haemophagocytosis or intracellular organisms were observed. Histological assessment of the haematoxylin and eosin (H&E)stained bone marrow trephine biopsy specimen revealed extensive replacement of the bone marrow by large foamy macrophages (top right, ×40), confirmed by positive cytoplasmic CD68 staining (bottom left, ×40). The contents of the cytoplasmic vacuoles stained a pale blue grey with H&E, whilst there was positivity with Congo Red (bottom right, ×40); no birefringence was observed. Haemopoiesis was overall markedly reduced although fat spaces and vasculature appeared preserved. In addition, some of the bone spicules appeared to be nonviable with no osteocytes visible and no osteoblasts or osteoclasts on the margins. The patient admitted to crushing various tablets for intravenous injection including methadone, methylphenidate and buprenorphine. Polyvinylpyrrolidone (PVP) has been documented as an excipient for opioidreplacement therapies including methadone and buprenorphine. Prolonged intravenous administration leads to tissue accumulation resulting in a form of acquired storage disease. This entity has been referred to as PVP syndrome or PVP storage disease. Patients injecting high molecular weight formulations have been found to have accumulation of foamy macrophages suspected to contain PVP in the bone marrow, liver, thyroid and skin.