Patellar tumors

Pain in the anterior knee has become synonymous with patella chondromalacia . However, pain also is the first sign of a tumor of the patella. Tumors of the patella are rare, but they often are mistaken for other benign lesions . Benign tumors of the patella are more frequent than malignant tumors (73% versus 27%). The most common benign neoplasms are giant cell tumor and cho ndroblastoma. Margin of the lesion, cortical involvement, trabecular patter n, and type of the matrix are important features for a radiographic diagnos is. Bone scans, computed tomography scans, and magnetic resonance images ar e used for staging of the tumor before surgery. Curettage only should be co nsidered for patients with Stage 1 or Stage 2 benign lesions. Patellectomy is indicated for patients with Stage 3 aggressive benign tumors and for pat ients with Stage IA malignant tumors. A patellectomy with excision of invol ved soft tissues is used in patients with Stage IB tumors, whereas in patie nts with Stage IIA tumors, an extensive patellectomy is indicated. In patie nts with Stage IIB tumors, an extraarticular resection of the knee is prefe rred when there is a small soft tissue involvement, but amputation is neces sary when there is a large soft tissue mass.