Solitary Fibrous Tumor on Needle Biopsy and Transurethral Resection of the Prostate

Department of Pathology, The Johns Hopkins Hospital, Baltimore, MD 21231, USA.
American Journal of Surgical Pathology (Impact Factor: 5.15). 06/2007; 31(6):870-6. DOI: 10.1097/01.pas.0000213416.23256.71
Source: PubMed


One of the least commonly encountered spindle cell tumors seen on prostatic needle biopsy or transurethral resection (TUR) of the prostate is solitary fibrous tumor (SFT). We studied 13 cases of SFTs identified on either prostate needle biopsy (n=9) or TUR of the prostate (n=4). Mean patient age at diagnosis was 63 years (range: 46 to 75 y; median: 65 y). Twelve men presented with urinary tract symptoms and 1 patient was biopsied during work-up of bone metastases. Ten cases were SFTs originating in the prostate, 2 cases arose between the prostate and rectum extending into the prostate (n=2), and 1 case was a pelvic mass without infiltration of the prostate. In 9 cases, a complete tumor resection was attempted by cystoprostatectomy (n=2), radical prostatectomy (n=4), pelvic exenteration (n=2), or pelvic tumor resection (n=1). Enucleation (n=1) and TUR (n=1) were performed in 2 other cases. Tumor sizes ranged from 8.5 to 15 cm in 7 radically resected cases. Mitotic rates were 3 to 5 per 10 high power fields in 5 cases, with the remaining cases having either rare (n=4) or no mitoses (n=4). Seven cases demonstrated areas of necrosis. Based on a combination of increased cellularity, mitotic activity, necrosis, nuclear pleomorphism, and infiltrativeness, 4 prostatic SFTs were malignant, 4 were benign, and 2 were borderline. Of the 3 non-prostatic SFTs, 1 was malignant and 2 were borderline. All tumors but 1 were immunoreactive for CD34 (n=12). Material for additional immunohistochemistry was available for the majority of cases with positive stains for Bcl-2 (11/11), CD99 (7/10), beta-catenin (5/10), and c-kit (0/11). Three SFTs demonstrated >or=10% p53 immunoreactivity including 1 tumor with 50% positivity; and 3 cases had Ki-67 rates of >or=20%. Although all SFTs were initially clinically considered to be of prostatic origin, some of the cases arose in the pelvis with secondary involvement of the prostate. Approximately 50% of prostatic SFTs were malignant. Even in the prostatic and nonprostatic SFTs with no overt malignant features, sometimes it was necessary to remove the prostate and in some instances the adjacent organs because of the large size of the tumors. SFTs must be differentiated from other spindle cell neoplasms of the prostate especially from gastrointestinal stromal tumors that may arise from the rectal wall with invasion of the prostate or from the region between the rectum and the prostate.

17 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A rare case of Solitary fibrous tumor (SFT) of the pelvis is reported. A 76-years-old man presented with a low abdominal pain, acute urine retention and constipation. Imaging studies (US, CT MR) showed an 17 x 10 x 9 ovoid mass in the pelvis, dislocating bladder and rectum. Finally, trans-rectal needle biopsy suggested the diagnosis of SFT. En bloc excision of tumor and rectum (because of strong adhesions) was performed. Histological examination showed spindle and fibroblastic-like cells dispersed in collagenous areas with positive stains for CD34, bcl-2, CD99 and it confirmed diagnosis of SFT. No postoperative complications occurred, only vesico-sphincter dyssynergia was found by urodynamics. After 5 years, patient is disease-free. SFT is, usually, benign tumor with slow growth and excellent prognosis. Complete surgical resection is the only curative treatment. However, 10-15% of SFT are malignant and histological findings cannot always predict clinical behaviour. For this reason, careful and long term follow-up is necessary after surgery.
    Annali italiani di chirurgia 11/2010; 81(6):457-60. · 0.60 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Testicular masses in adults are most likely seminomatous or non-seminomatous germ cell tumours. Paratesticular tumours are far less frequent. Most lesions within this category are variants of fibrous pseudotumours. Solitary fibrous tumours (SFT) with characteristic (hemangiopericytoma-like) vascular structures are rare neoplasms that in the vast majority arise in the pleura, although extrapleural localisations in virtually every organ have been reported. A 64-year-old male nursing case was presented with a testicular swelling on the left side and recurrent testicular pain. Physical examination revealed a distinct mass at the left spermatic cord. The tumour marker levels were normal. The patient's history included an HIV infection as well as neurosyphilis. The sonographic examination showed a heterogeneous and hyperperfused tumour, MRI examination a 3.2 x 4.3 cm measuring heterogeneous tumour above the left epididymis. An inguinal orchiectomy was performed due to the unclear dignity. The histological examination revealed a solitary fibrous tumour. In cases of paratesticular tumours, rare tumours like solitary fibrous tumours have to be considered. Certainty regarding the dignity of the tumour can only be achieved by surgical exposure and excision.
    Aktuelle Urologie 08/2008; 39(4):305-8. DOI:10.1055/s-2008-1038162 · 0.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Prostatic mesenchymal tumors encompass various benign and malignant neoplasms that may derived from the intrinsic prostatic stroma or from associated elements including muscle, connective tissue, blood vessels, and neural structures. The differential diagnosis of these tumors is broad and encompasses prostatic epithelial processes that demonstrate prominent spindle cell morphology, as well as mesenchymal tumors that secondarily involve the prostate. Careful morphologic examination, clinical history, and judicious use of a limited panel of immunohistochemical markers and molecular tests aid in the proper diagnosis of these lesions. This article provides a structured guide for the analysis and diagnosis of both benign and malignant prostatic mesenchymal lesions and highlights key features that distinguish these entities within the differential diagnosis of prostatic spindle cell lesions.
    Surgical Pathology Clinics 12/2008; 1(1):105-128. DOI:10.1016/j.path.2008.07.003
Show more