Diffuse Hepatic and Spleen Uptake of Tc-99m MDP on Bone Scintigraphy Resembling Liver-Spleen Scintigraphy in a Patient of Plasma Cell Tumor

The present case demonstrates a diffuse intense hepatic and, to a lesser degree, spleen, Tc-99m MDP uptake on a routine bone scintigraphy resembling liver-spleen imaging. A 49-year-old female with a history of anaplastic plasma cell tumor and suffering from bone pain was referred for bone scintigraphy to evaluate possible bone metastases. The bone scintigraphy showed diffuse hepatic and spleen uptake of Tc-99m MDP resembling liver-spleen imaging. Furthermore, bone uptake of Tc-99m MDP was significantly diminished and there were no abnormal foci throughout the skeleton. The bone scintigraphy of the present case of an anaplastic plasma cell tumor suggests the possible presence of amyloidosis. 1. Introduction Amyloidosis is characterized by an abnormal extracellular deposition of amyloid in various tissues and organs of unknown cause [1, 2]. The pathogenesis of amyloid fibrils is associated with amino acid replacements in prefibrillar proteins and with protein instability [1]. Also, its clinical presentation, involving either single or multiple organs, results in different signs and symptoms [2]. Depicting the presence of amyloid protein in the tissue, mostly through invasive methods, is the primary way of diagnosing amyloidosis [3]. We describe a 49-year-old female with a history of anaplastic plasma cell tumor. Her bone scintigraphy with Tc-99m MDP suggested the possible presence of amyloidosis, by revealing intense diffuse tracer uptake in the liver and spleen. 2. Case Report A 49-year-old female was referred for a bone scintigraphy for identification of possible bone metastasis. She complained of general bone pain. Her past history included a lytic lesion in the right mandible that had been treated with chemotherapy and radiotherapy. Several investigations included bone marrow aspiration cytology and immunohistochemistry (IHC), suggesting anaplastic plasma cell tumor. The serum electrolyte, calcium, and phosphate levels were increased. The serum creatinine level was also increased (Cr: 3.5？mg/dL). Ultrasonography revealed that the patient had a mild splenomegaly. A bone scan revealed diffusely and intensely hepatic 99Tc-MDP uptake, and to a lesser degree in the spleen. Decreased skeletal uptake on bone scan was also observed (Figure 1). We suggested the possibility of immunoglobulin amyloidosis resulting from disturbed renal function in the base of the patient’s underlying disease. Figure 1: Anterior and posterior whole body bone scan, performed three hours after the intravenous administration of Tc-99m MDP, showed diffuse and intense tracer uptake in