Transitional cell carcinoma of the clitoris: direct implantation or metastasis.

Transitional cell carcinoma (TCC) of the bladder is the seventh most frequent cancer of women. The possible mechanisms of local tumor recurrence are seeding and multicentricity. Distant metastases are most frequently as a result of vascular or lymphatic spread and to a lesser extent by seeding of the tumor cells with urine or transurethral instrumentation. We report a clitoral metastasis of a TCC of the bladder, which is a very unexpected and extremely rare site for metatstasis and discuss whether the possible mechanism is vascular spreading or direct seeding. To our knowledge this is the third case in the literature.