technetium-tc-99m-sulfur-colloid and Soft-Tissue-Neoplasms

Indium-111-labeled leukocyte imaging, performed on a patient with a calcified mass in the right thigh, demonstrated labeled leukocyte accumulation in this mass. Technetium-99m-sulfur colloid imaging was performed to differentiate labeled leukocyte uptake in heterotopic bone marrow from uptake in a focus of infection. Leukocyte and sulfur colloid images were virtually identical, and the study was interpreted as without evidence of infection. Excision of the mass revealed an angiomatoid malignant fibrous histiocytoma with metaplastic bone formation. While no marrow elements were present in either the tumor or the metaplastic bone, phagocytosis of leukocytes by tumor cells was identified. Phagocytosis of leukocytes by tumor cells may be another cause of white cell accumulation in uninfected neoplasms.

Topics: Adult; Histiocytoma, Benign Fibrous; Humans; Indium Radioisotopes; Leukocytes; Male; Phagocytosis; Radionuclide Imaging; Soft Tissue Neoplasms; Technetium Tc 99m Sulfur Colloid; Thigh

Hemangiopericytoma is a soft tissue tumor composed histologically of pericytes of Zimmerman, which line capillaries. These neoplasms have been observed throughout the body in soft tissue and bone. Presented here is a case of abdominal hemangiopericytoma proven histologically that simulated an accessory spleen on a number of studies including Tc-99m sulfur colloid imaging.

Topics: Abdomen; Choristoma; Diagnosis, Differential; Hemangiopericytoma; Humans; Male; Middle Aged; Soft Tissue Neoplasms; Spleen; Technetium Tc 99m Sulfur Colloid; Tomography, Emission-Computed