Gastrointestinal stromal tumor of the prostate: a case report and literature review.

We report a case of gastrointestinal stromal tumor (GIST) of the prostate in a 75-year-old man with dysuria and urinary retention. Digital rectal examination revealed a markedly enlarged prostate. The serum level of prostate-specific antigen was 0.2 ng/dL. Imaging studies showed an expanded prostate, measuring 6.7 x 5.6 x 5.5 cm, with heterogeneity in contrast enhancement. No metastatic disease was found. The pathologic diagnosis of prostatic GIST was made based on characteristic morphological features, immunoprofiles, and molecular analysis. The possibility of secondary involvement by a rectal GIST was excluded by radiological and intraoperative findings. To our knowledge, this is the second case of a primary GIST of the prostate reported in the literature.