Primary extragastrointestinal stromal tumor of the prostate: a case report.

Background: The published literature on primary prostatic extragastrointestinal stromal tumor (EGIST) is limited to several isolated case reports. No long-term follow-up is currently available for these patients in order to determine if the biologic behavior of prostatic gastrointestinal stromal tumor is different from those occurring in other sites.

Case: A 40-year-old man presented with symptoms of benign prostate hyperplasia. Magnetic resonance imaging revealed a huge prostatic mass restricted to the organ's capsule. After a complete resection and histopathologic study of the specimen, primary high-risk EGIST of the prostate was confirmed. The patient underwent adjuvant chemotherapy with imatinib. He has been observed for 32 months and is in good condition with no recurrence or metastasis.

Conclusion: Primary EGIST of the prostate is an extremely rare entity. It should be carefully distinguished from other spindle cell lesions. Complete surgical resection and chemotherapy with imatinib are important strategies of treatment.