Contemporary carly prostate cancer detection efforts frequently identify cancer at low clinical and pathologic stage, often resulting in small volumesm of tumor in radical prostatectomy speciments, The authors reported case in which adenocarcinoma could not be indentified in a radical prostatectomy specimen removed for biopsy-proven adenocarcinoma despite extensive effort. Genetic analysis confirmed that the biopsy specimen containing cancer and prostatectomy speciment were from the same patient, climinating the possibility of laboratory errors as the cause of not identifying cancer in the radical prostatectomy specimen. This experience is referred to as the “Vanishing cancer phenomenon.” Occasionally, cancer may be extremely difficult or impossible to find in the prostatectomy specimen despite exhaustive sampling. The incidence of this vanishing cancer phenomenon is probably increasing because more low stage cancers are being treated by prostatectomy. No method exists for predicting preoperatively which patients have small volumes of adenocarcinoma in the prostate. The inability to indentigy cancer in a prostate removed for biopsy-proven carcinoma may not be attributable to pathologise error.