Polyvinylpyrrolidone storage disease presenting as pathologic fracture and anemia: report of a case with imprint cytology.

Polyvinylpyrrolidone (PVP) storage disease can be caused by local injection and systemic parenteral administration of PVP-containing solutions. PVP has been used as plasma expander, a retardant in certain medicines, components of food additive, and hair care products. High-molecular-weight PVP polymers are prevented from renal excretion and are retained in the reticuloendothelial system. The clinical manifestations include skin lesions and hematologic and orthopedic complications because of bone marrow failure and bony destruction with infiltration of PVP storage histiocytes. Herein, we report a 65-year-old female patient with PVP storage disease presenting as femoral fracture and anemia. In our case, some gelatinous material was noted atthe fracture site, and the initial clinical impression was bony tumor or metastatic lesion. Imprint cytology showed some atypical cells exhibiting foamy cytoplasm and vacuoles. The biopsy specimen revealed that some blue-grayish, vacuolated cells infiltrate in the bone marrow spaces and regional soft tissue near fracture site. The unusual morphology caused a diagnostic dilemma, with the differential diagnosis, including metastatic carcinoma, chordoma, liposarcoma, and hereditary storage disease. The vacuolated cells were positive for CD68, mucicarmine, and Congo red stains, but negative for CK (AE1/AE3) and S-100 protein. Combing the patient's history with long-term intravenous supplement of PVP-containing blood solutions, PVP storage disease involving the bone and regional soft tissue was diagnosed.