Primary extragastrointestinal stromal tumors of the prostate: A case report and literature review

Extragastrointestinal stromal tumors with diffuse membranous distribution with bleeding: A case report

BACKGROUND

Extragastrointestinal stromal tumors (EGIST) and gastrointestinal stromal tumors are of similar pathological type and form. Here we report a rare case of EGIST diffusely distributed in membranous tissue in abdominal cavity, the feature of which included diffuse tumors at membranous tissue in entire abdominal cavity and spontaneous bleeding of the tumors.

CASE SUMMARY

The patient was a 71-year man and hospitalized due to continuous pain at lower abdomen for more than 10 days. Upon physical examination, the patient had flat and tough abdomen with mild pressing pain at lower abdomen, no obvious abdominal mass was touchable, and shifting dullness was positive. Positron emission tomography-computed tomography (CT) showed that in his peritoneal cavity, there were multiple nodules of various sizes, seroperitoneum, multiple enlarged lymph nodes in abdominal/pelvic cavity and right external ilium as well as pulmonary nodules. Plain CT scanning at epigastrium/hypogastrium/pelvic cavity + enhanced three-dimensional reconstruction revealed multiple soft tissue nodules in abdominal/pelvic cavity, peritoneum and right groin. Tumor marker of carbohydrate antigen 125 was 808 U/mL, diffuse tuberous tumor was seen in abdominal/pelvic cavity during operation with hematocelia, and postoperative pathological examination confirmed EGIST. Imatinib was administered with better therapeutic effect.

CONCLUSION

Gene testing showed breast cancer susceptibility gene 1 interacting protein C-terminal helicase 1 and KIT genovariation, and the patient was treated with imatinib follow-up visit found that his clinical symptoms disappeared and the tumor load alleviated obviously via imageological examination.

Primary extragastrointestinal stromal tumor of the prostate: review of the literature and case report

The extragastrointestinal stromal tumor (EGIST) is defined as a mesenchymal neoplasm arising from soft tissues outside the gastrointestinal tract, and the prostate is a rare presentation site.

Case presentation

A 58-year-old man was presented with lower urinary tract symptoms for 6 months. A digital rectal examination revealed a markedly enlarged prostate with a smooth, bulging surface. Prostate-specific antigen density was 0.5 ng/ml. MRI of the prostate showed an enlarged prostatic mass with hemorrhagic necrosis. Transrectal ultrasound-guided prostate biopsy was performed and pathological reports suggested a gastrointestinal stromal tumor. The patient refused radical prostatectomy and received only imatinib treatment.

Clinical discussion

The diagnosis of EGIST of the prostate is extremely rare and depends on the histopathologic features with immunohistochemical results. The treatment is essentially based on radical prostatectomy, but there are other therapeutic modalities associating surgery with adjuvant or neoadjuvant chemotherapy. For patients refusing surgery, treatment with imatinib alone appears to be a therapeutic solution.

Conclusion

Despite the rarity, EGIST of the prostate should be included in the differential diagnosis of patients presenting with lower urinary tract symptoms. There is no consensus regarding the treatment of EGIST, and the patients are treated as per the risk stratification.