Splenorenal fusion: heterotopia simulating a primary renal neoplasm.

We report an instance of splenic heterotopia arising within the left kidney of an otherwise normal female infant. Embryologic considerations suggest that fusion of nephrogenic mesoderm and splenic anlage in the second month of gestation accounts for the observed findings. Although splenic-mesonephric (splenogonadal) fusion is a well-characterized, although rare, malformation, we were unable to find any previous description of splenic-metanephric fusion.

Villonodular synovitis with synovial chondromatosis.

Pigmented villonodular synovitis and synovial chondromatosis are uncommon benign lesions involving the articular surfaces of diarthrodial joints. Reported is a case of a benign synovial lesion of the temporomandibular joint, which was clinically thought to be a malignant parotid compartment tumor, showing histologic features of both pigmented villonodular synovitis and synovial chondromatosis. A review of the literature reveals a single case in which cartilaginous bodies were found in the joint; however, the synovial tissue showed features of only villonodular synovitis, with no mention of cartilaginous foci.