[Ectopic deposits of Tamm-Horsfall protein. A psuedo-tumoral lesion]

Three cases of unusual deposits of Tamm-Horsfall protein in peripelvic and perirenal fat tissue are reported. A renal tubular rupture leads to the deposition of this protein. In the first case, the association of the deposits with epithelial structures, raised the possibility of a bladder carcinoma infiltration. These deposits simulated on the X-ray examination, a pelvis neoplasm in our second patient and a tuberculosis in the third case. However the particular microscopic appearance of Tamm-Horsfall protein, its intense staining with the periodic-acid-Schiff, and its positivity with a specific antibody led to the diagnosis.