Stromal Tumors in the Prostate

Abstract

Stromal tumors of the prostate are rare mesenchymal tumors of the prostate stroma,
in the form of spindle cell tumors, which are differentiated by cellularity, mitotic index,
cellular atypia, and necrosis. These tumors are classified into two; prostatic stromal
tumors of uncertain malignant potential (STUMP) and prostatic stromal sarcomas (PSS).
The incidence is about 0.1-0.2% of the total incidence of prostate cancer. The
pathogenesis of prostate stromal tumors is based on origin, clonal and chromosomal
abnormalities. Clinical symptoms of complaints lead to lower urinary tract obstruction,
dysuria and pollakiuria as well as abnormalities in the rectal toucher (RT) examination.
Macroscopically, brownish-white masses were found showing a solid or solid-cystic
pattern. Radiological examination can use transrectal ultrasound (TRUS), CT Scan and
MRI. Histopathologically, prostate STUMP has five different patterns, namely the
degenerative atypia pattern, hypercellular stroma pattern, phyllodes-type growth
pattern, myxoid pattern, and epithelioid stromal pattern. Meanwhile, in PSS, there are
histological patterns of storiform, epithelioid, fibrosarcomatous, and patternless growth
patterns. Then PSS was subclassified into two, namely low grade and high grade
tumors. Immunohistochemical examination showed immunoreactivity for CD34, PR,
smooth muscle actin (SMA), desmin, HHF35, smooth muscle actin, vimentin and
androgen receptors and negative for estrogen receptors, CD117 and S-100. The
differential diagnosis is rhabdomyosarcoma, leiomyosarcoma, inflammatory
myofibroblastic tumor, sarcomatoid carcinoma, benign prostate hyperplasia, smooth
muscle tumor, gastrointestinal stromal tumor, and solitary fibrous tumor. Prognosis of
prostate STUMP is better than that of PSS. Treatment of STUMP is currently unknown.
Definitive resection can be performed taking into account the patient's age, treatment
preference, and the size or size of the lesion. Treatment for PSS radical prostatectomy,
cystoprostatectomy, or pelvic exenteration for local aggressive tumors.