Synovial chondromatosis

Case contributed by Rocio Soledad Garcia
Diagnosis certain


Gonalgia, tumefaction on the internal border of the right patella of progressive growth with notable functional limitation.

Patient Data

Age: 7 years
Gender: Male



Nodular image of soft tissue density with small calcific images inside.  Intraarticular location medial to the patella generating cortical irregularity of the internal articular facet and lateral displacement of the patella. Increase of the intraarticular liquid. 



A nodular image of slightly heterogeneous density is visualized, with small punctate calcifications in its interior, it presents intra-articular location, medial to the patella, causing irregularity of the cortical of the internal facet and minimal lateral displacement of the same. It is associated with a slight increase in articular fluid. It measures approximately 50 x 33 x 19 mm (longitudinal, transverse, and anterior-posterior).



A hyperintense T1 lesion is identified with a tendency to heterogeneity in T2 sequences. The lesion is described in an intra-articular location, originating in the synovium that contacts the patella generating erosion of the patella and lateralization of the patella. Increase of intra-articular fluid.

Gross Pathology


We present the postoperative macroscopic image. A sample was taken for an anatomopathological study. 

Case Discussion

We present the case of a 7-year-old patient with gonalgia and palpation of a lesion on the inner border of the right patella. However, there were no alarm signs that could suggest tumor or infectious pathology (fever, general condition, alteration of analytical parameters, increase in temperature or size of the tumor), and the patient did not relate direct trauma before the onset of symptoms. He was diagnosed with synovial chondromatosis. 
Synovial chondromatosis is benign metaplasia of the synovial membrane with the formation of cartilaginous nodules of the connective tissue of the synovial membrane of joints, sheaths, tendons or bursae. It is an infrequent entity in children, a very voluminous lesion (unusual because of its large size); it requires early surgical treatment. It affects 1 in 100,000 people, primarily adults, and is extremely rare in pediatric age. It predominates in large joints, especially the knee, with non-specific symptomatology. 


Case contributed by Dra. Rocio Soledad Garcia and Dr. Tito Alfredo Atencia Rincón

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