Solitary fibrous tumor of the seminal vesicle: A case report

Abstract

Rationale: Solitary fibrous tumor (SFT) is an unusual neoplasm, especially when it originates from the seminal vesicle. Herein, we describe a case of SFT that arises from the seminal vesicle.

Patient concerns: A 66-year-old man presented to our hospital complaining of a huge irregular tumor in his pelvis during a health checkup. He was worried that the tumor could be a malignant tumor and hence wanted to undergo further examination and therapy.

Diagnosis: An inhomogeneous, mixed soft tissue tumor in the pelvis was found during computed tomography (CT) and magnetic resonance imaging. The tumor showed heterogeneous and delayed enhancement during contrast-enhanced CT. The tumor was diagnosed as a cystadenoma originated from the seminal vesicle due to its imaging features. But the pathological diagnosis was SFT that originated from the seminal vesicle.

Interventions: Laparoscopic seminal vesicle tumor resection was performed.

Outcomes: There was no evidence of recurrence at the 6-month follow-up.

Lessons: SFT in the seminal vesicle is extremely rare. It is very difficult to distinguish SFT in the seminal vesicle from the primary tumors as both have similar imaging features. We describe the tumor with SFT being considered as a differential diagnosis when the tumor is found in the seminal vesicle.

Figure 1

Computed tomography images of the pelvis (A. axial image of plain CT scan, B. axial image of the arterial phase, C. axial image of the delayed phase, D. coronal image of the delayed phase) show an irregular solid-cystic tumor with an obvious inhomogeneous enhancement and delayed reinforcement. Coronal image shows the clear boundary between the tumor and the prostate. A calcification is observed in the prostate.

Figure 2

Conventional unenhanced pelvis during an MRI (A. axial T₁WI, B. axial T₂WI, C. coronal T₂WI, D. sagittal T₂WI). An irregular tumor with isointensity on T₁WI and hyperintensity on T₂WI is observed, and the tumor has a much low signal on T₂WI. The prostate is normal in shape and is compressed. MRI = magnetic resonance imaging, T₁WI = T1-weighed imaging, T₂WI = T2-weighed imaging.

Figure 3

Pathological findings A. HE staining reveals the hypercellular areas, the rich blood vessels, and the bunch of collagen separating the cells. B. Tumor cells are positive for CD34.