Objective

To demonstrate a case of a cellular angiofibroma (CAF) located deep in the prostatorectal space and penetrating the prostatic apex, which was treated by robot-assisted laparoscopic surgery by posterior approach towards tumor dissection.

Material and methods

The patient was a 53-year-old man with complaints of nocturia and incomplete bladder emptying with a history of a 3 cm prostatic utricular cyst and two prior negative biopsies for persistently elevated PSA. His current PSA was 9,35 ng/ml. MRI showed a PIRADS 3 lesion in the left peripheral zone alongside a 7 × 7.3 cm mass involving the prostatic apex on the right side, extending caudally to the bulb of the corpus spongiosum, partially encircling the membranous urethra, and projecting cranially between the prostate and the anterior rectal wall.

A transperineal fusion prostate biopsy revealed non-malignant tissues with spindle-cell proliferation and hemangiopericytoma-like vessels and benign prostate tissue.

Robot-assisted laparoscopic exploration by an entirely posterior approach towards tumor dissection was performed (by L.T.) with minimal distortion of the neurovascular tissues and planes supporting the urethra.

Results

Immunohistochemical analysis confirmed CAF, with negative surgical margins. Following surgery, the patient's urinary storage and voiding symptoms were resolved entirely. His erectile function was unaltered, but he had a prolonged complaint of hematospermia. The 1-year follow-up MRI showed no evidence of disease recurrence, and that the utricle cyst remained.

Conclusion

CAF is a rare, benign soft-tissue neoplasm that typically occurs superficially in the inguinoscrotal region or perineum in males (1). It was first described in 1997 and also referred to as male angiomyofibroblastoma-like tumor [1,2] A comprehensive diagnostic work-up is required to exclude other potential diseases such as angiomyxoma, prostate cancer, or tumors of the seminal vesicles. The diagnosis can only be established by appropriate immunohistological staining [3,4]. To date, there have been only three similar reports for the occurrence of CAF in deep pelvic locations, in which an open surgical treatment approach was preferred [[5], [6], [7], [8]]. Our case is unique as being the first reported CAF localized in the prostatorectal space where complete excision is achieved without complications by minimally invasive surgery. The challenging size and site of the tumor entailed an exclusive posterior approach as performed in robotic Retzius-sparing radical prostatectomy with optimal exposure to avoid the neurovascular and sphincteric tissues.