Mice that are deficient in either the Pms2 or Msh2 DNA mismatch repair genes have microsatellite instability and a predisposition to tumours. Interestingly, Pms2-deficient males display sterility associated with abnormal chromosome pairing in meiosis. Here mice deficient in another mismatch repair gene, Mlh1, possess not only microsatellite instability but are also infertile (both males and females). Mlh1-deficient spermatocytes exhibit high levels of prematurely separated chromosomes and arrest in first division meiosis. We also show that Mlh1 appears to localize to sites of crossing over on meiotic chromosomes. Together these findings suggest that Mlh1 is involved in DNA mismatch repair and meiotic crossing over.

Synovial cell sarcoma is an uncommon soft-tissue malignant tumour. These tumours have common radiological features with a variety of both benign and malignant lesions. However, there is a variety of imaging findings that can suggest a pre-biopsy diagnosis of synovial cell sarcoma. This pictorial review aims to describe the imaging features of synovial sarcoma in a series of cases with various age ranges and tumour locations. In addition, the pathology, staging, prognosis and management of synovial sarcoma is briefly discussed.

No abstract