SOLITARY FIBROUS TUMOR OF PROSTATE – A CASE REPORT

diagnosis of SFT was made. In addition, we review the literature and discuss the challenging issues of misdiagnosis. The case is presented in view of its rarity. ABSTRACT


INTRODUCTION:-
Solitary Fibrous Tumor(SFT) is a spindle cell tumor derived from [1] myobroblasts, most commonly found in pleura.
Prostate SFT is relatively uncommon with less than 20 cases reported [2] in the literature worldwide. It represents a clinical challenge with other spindle cell lesion of prostate regarding both diagnosis and treatment.

Case History.
A 62 year-old male patient was presented with urinary frequency and urgency in Urology out patient department. The digital rectal examination revealed gross enlargement of prostate. The pelvic ultrasound examination also showed enlargement of median lobe of prostate compressing over the base of urinary bladder and there was mild hydronephrosis.
His hematological and biochemical parameters were within normal range and PSA level was also within normal range.
Based on clinical and radiological ndings, the case was subjected to open prostatectomy.
Gross examination of the surgical specimen showed two irregular grey-white nodular masses measuring 7×5×4 cm and 6×5×4cm with focal grey-brown areas. Cut surface showed solid grey-white whorled areas and no necrosis or hemorrhages ( Figure 1) .
Microscopic examination revealed a well circumscribed lesion consisting of proliferating broblasts along with thick, hyalinized blood vessels and few staghorn-like blood vessels. The lesion is enclosing few benign prostate glands. At the periphery of the tumor broblasts are admixed with smooth muscle cells. There is no evidence of abnormal mitosis or necrosis.(gure 2&3).
Two blocks were sent for immunohistochemical study and they showed strong positivity for CD34 in blood vessels.
Based on microscopic ndings and IHC prole, the mass was diagnosed as solitary brous tumor(SFT).

DISCUSSION
Although formerly believed to be restricted to pleura, tumors showing features of classical solitary brous tumors have been increasingly 3 recognized in extrapleural sites (peritoneum, retroperitoneum, mediastinum, nasopharynx, oral cavity, orbit, prostate and breast.) The waning popularity of diagnosis of hemangiopericytoma also coincided with increasing popularity of the diagnosis of SFT, a pleura 4 based lesion rst described by Kleumperer and Rabin. The specic symptoms relate to the location of the tumor. Hypoglycemia has been reported in about 5% of SFTs, most often located in the pelvis and retroperitoneum. It is mediated through the production of insulin-like [1] growth factors by the tumors. SFTs grow in deep soft tissues as a circumscribed mass or as exophytic lesion from serosal surfaces. Most measures 5-10 cms in diameter and have grey-white to red-brown cut section. Hemorrhagic and cystic degeneration may be seen. SFTs are highly variable in appearance depending on the relative proportion of cells and brous stroma. Cellular type of SFT(corresponds to classical hemangiopericytoma) consists of tightly packed round to fusiform cells with indistinct cytoplasmic borders that are arranged around an elaborate vasculature. The vessels form a continuous, ramifying vascular network that exhibit striking variation in caliber. The dividing sinusoidal vessels have stag-horn or antler-like conguration.
Diffuse sclerosing pattern has paucicellular areas with prominent collagen ber deposition and stromal hyalinization. Tangled network of broblast-like cells squeezed between abundant collagen bers(patternless pattern of Stout). The cellular SFTs express CD34(80-90%), CD99(70%), Bcl (30%), EMA(30%), actin(20%) 2 . [1& 5] immuno reactivity Solitary Fibrous Tumor (SFT) of prostate is an unusual mesenchymal neoplasm. We report SFT in a 62 year-old man which was clinically misdiagnosed as benign prostatic hyperplasia (BPH). The specimen of surgically resected two prostate mass, we received were solid grey-white nodular on cut surface. Based on histopathological ndings and IHC assessment, a diagnosis of SFT was made. In addition, we review the literature and discuss the challenging issues of misdiagnosis. The case is presented in view of its rarity.
The differential diagnosis of SFT may include 1. Fibrous histiocytoma -which usually displays a more prominent, more uniform spindle cell pattern with distinct storiform arrangement of tumor cells. 2. Synovial sarcoma -where CD34 expression is not seen.
3. Mesenchymal Chondrosarcoma -shows foci of well differentiated mature cartilage or ill dened foci of immature [6] cartilage.
Majority of SFTs are histologically benign. However a small percentage of cases possess atypical features like large size, increased mitotic activity(more than 4MF/10 HPF), high cellularity with [7] pleomorphic tumor cells and foci of hemorrhagic and necrosis.
Mesenchymal neoplasms of prostate are uncommon and pose a diagnostic difculty because of their overlapping histomorpholgical features and IHC characteristics. SFT is considered as a least common mesenchymal neoplasm of prostate accounting for merely 30 cases [2] globally.
In the present case, the initial clinical examination and laboratory workup(normal PSA level) favoured the diagnosis of nodular hyperplasia of prostate. Based on histopathological and IHC evaluation of the specimen a diagnosis of SFT of prostate was rendered.

CONCLUSION
Solitary brous tumor of prostate can prove to be a diagnostic challenge for pathologist & clinician because it mimics other mesenchymal neoplasms.We report an additional case of prostate SFT which was initially misdiagnosed as BPH and histologically diagnosed as SFT of prostate.