Pathology of Prostatic Stromal Sarcoma 

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Prostatic stromal sarcoma is a rare malignant neoplasm that is believed to originate from specialized stromal prostatic cells. ^{[1, 2, 3, 4, 5]} At present, there is still debate on its specific definition, pathology, and prognosis. ^{[3, 6]}

This tumor was initially named as atypical stromal hyperplasia, cystosarcoma phyllodes, prostatic cystic epithelial-stromal tumor, and mullerian adenosarcomalike tumor; most of these were presented as a few isolated case reports and without distinction from other spindle cell neoplasms of the prostate. ^{[1, 7, 8]} The phyllodes pattern of mesenchymal proliferation has been included with stromal tumors of uncertain malignant potential (STUMP). ^{[9, 10, 11, 12]}

Prostatic stromal sarcoma was formally described by Gaudin et al in 1998. ^[1] The current World Health Organization (WHO) (also known as l’Organisation Mondiale de la Sante [OMS]) classification includes this tumor as a distinctive spindle cell neoplasm. ^[13] (See the related images below.)

The true incidence of prostatic stromal sarcomas has not been established because of the rarity of this tumor. ^{[1, 2, 3, 4, 13, 14, 15, 16, 17, 18, 19]} In the largest series, patients’ ages ranged from 25 to 86 years, and at least one half of these patients were younger than 50 years. ^{[1, 3, 4, 13]} There have also been reported cases in younger adults. ^{[14, 15]}

Sarcomas arising in the prostatic stroma in children are virtually always rhabdomyosarcomas. ^{[20, 21]} Some authors consider stromal tumors of uncertain malignant potential (STUMPs) and stromal sarcoma to be in a spectrum of the same disease, ^{[3, 4]} whereas others favor STUMP as a type of hyperplasia with little to no malignant potential. In contrast to STUMPs, stromal sarcomas tend to affect a slightly younger population. ^[4]

The prostate has a complex stromal-epithelial interaction that responds to hormonal stimulation that is responsible for prostatic epithelial morphogenesis, differentiation, proliferation, and expression of prostate-specific proteins. It is believed anomalous or exaggerated stimulation in these pathways may give origin to stromal sarcoma. ^[22]

Stromal sarcoma may arise de novo or coexist with either preexistent or concurrent STUMP, suggesting a potential for STUMP in dedifferentiate into stromal sarcoma. Indeed, Herawi et al studied 50 stromal tumors of prostate. The investigators found 14 stromal sarcomas, of which 7 were associated with STUMP. ^[2] Due to the relation and coexistence of STUMP and prostatic stromal sarcomas in the same cases as reported by Herawi et al, the term STUMP seems to be acceptable.

There is no specific site of occurrence of stromal sarcoma within the prostate. However, these tumors have been reported to arise more often from the posterior region of the prostate, and some extend to the vasa deferentia and seminal vesicles. ^{[16, 23, 24]} Some large tumors may protrude outside the prostate and mimic gastrointestinal stromal tumors or other neoplasms arising outside the prostate.

Common clinical presentations in men with prostatic stromal sarcoma are urinary retention, abnormal digital rectal examination (DRE), hematuria or hematospermia, and a palpable rectal mass. Although serum prostate-specific antigen (PSA) is usually negative, interestingly, there are also some reported cases with either sole or concurrent elevation in serum PSA. ^{[1, 3, 17, 18, 25]} Although there are some reports of combined stromal sarcoma with prostatic adenocarcinomas, it is likely that these represent sarcomatoid carcinomas (carcinosarcomas) rather than true primary sarcomas colliding with prostatic carcinomas. ^[17] Although there have been reported cases, sarcomatoid carcinomas of the prostate are more likely to occur than 2 separate colliding tumors.

There is no specific gross finding in these tumors. Prostatic stromal sarcomas can be solid or mixed with cystic areas, and they may show a tan to white cut surface and areas of edema and hemorrhage. Necrosis may also be found, especially in high-grade tumors. ^{[4, 25]}

Size is variable and has ranged from 2 to 18 cm in the hitherto reported cases. Interestingly, size has not correlated with the grade or clinical behavior of the tumor in most cases. ^{[2, 3, 4]}

Stromal sarcomas (see the images below) are histologically characterized by stromal overgrowth, variable cellular atypia, mitosis, and increased cellularity. They are further divided into low-grade and high-grade tumors, based on moderate to high cellular atypia and hypercellularity in high-grade tumors. Other findings such as necrosis and high mitotic counts are more commonly found in high-grade neoplasms. ^{[17, 18, 26]}

The stromal component can be solid or interspaced with normal glandular elements (see the images below). The most common patters are the storiform, epithelioid, fibrosarcomatous, or “patternless-type.” ^[4] Leaflike structures, resembling breast phyllodes tumor, are also found. These are more associated with low-grade sarcomas, and on histologic grounds alone, it may be difficult to predict the behavior of such tumors because of their bland appearance. The distinction between low-grade prostatic stromal sarcomas and stromal tumors of uncertain malignant potential (STUMPs) is based on the degree of cytologic atypia, and they are supported by the local aggressive behavior found in low-grade sarcomas. ^{[1, 3]}

As a neoplasm originated from specialized prostatic stroma, stromal sarcomas are progesterone- receptor (PR) positive, normally in a diffuse pattern. Occasional cases have shown estrogen-receptor (ER) positivity. CD34 and vimentin are both expressed diffusely in most cases. Smooth muscle actin is reportedly positive in some stromal tumors of uncertain malignant potential (STUMPs) but not in stromal sarcomas.

Rare desmin positivity is acceptable and is found in a minority of the cases. Beta-catenin and p53 expression are more commonly found in high-grade sarcomas, but sometimes they are also expressed in low-grade neoplasms. ^[4] Cytokeratins are negative in all reported cases. A high Ki-67 index is seen in most high-grade cases, but this finding is of little utility in the diagnosis of these neoplasms.

The current literature provides no data about specific molecular or genetic abnormalities in prostatic stromal sarcoma; neither are there studies that show any specific alteration that could predict the development of a stromal sarcoma from a stromal tumor of uncertain malignant potential (STUMP).

Low-grade sarcomas are locally aggressive neoplasms that can show contiguous involvement of seminal vesicles and extraprostatic extension. They normally do not metastasize or involve the bladder and rectum. ^{[1, 4]} but the true clinical behavior of these neoplasms is not entirely known, as only a few cases have been reported. It has been suggested that even low-grade sarcomas can locally invade, despite having at times a relatively bland cytology. ^[4]

However, high-grade neoplasms are more aggressive, with a higher prevalence of spread to the seminal vesicles, bladder, and rectum. Surgical margins are sometimes difficult to obtain because of involvement of adjacent structures. Vascular invasion has also been shown to be present in high-grade sarcomas, with selected cases demonstrating metastases to the liver and lung. ^{[2, 18, 27]}

Although there is no specific staging system for prostatic stromal sarcoma, pathologists should document the status of margins, distance to the closest margin, involvement of the seminal vesicles, and extraprostatic extension, similar to what is performed in adenocarcinomas. This process will provide clinicians with necessary information.

Because prostatic stromal sarcoma is a rare tumor, there are limited data about its prognosis, mostly in a very few case reports or from series with a small number of cases. Low-grade stromal sarcomas can be locally invasive, but these tumors normally do not metastasize.

The high-grade counterpart is more aggressive and may lead to death mainly because of metastasis or early local invasion. A minority of patients diagnosed with high-grade stromal sarcomas showed poor short-term survival if they were diagnosed early with resection with clear margins. Cases with distant metastasis behaved variably, with some early deaths due to widespread metastases and others showing long-term survival years after their initial presentation. ^{[16, 17]}

Patients are normally treated with radical prostatectomy or cystoprostatectomy. There are no current data to evaluate the effectiveness of chemotherapy or radiotherapy. ^{[1, 2, 18, 23]}

Gaudin PB, Rosai J, Epstein JI. Sarcomas and related proliferative lesions of specialized prostatic stroma: a clinicopathologic study of 22 cases. Am J Surg Pathol. 1998 Feb. 22(2):148-62. [Medline].

Herawi M, Epstein JI. Specialized stromal tumors of the prostate: a clinicopathologic study of 50 cases. Am J Surg Pathol. 2006 Jun. 30(6):694-704. [Medline].

Herawi M, Montgomery EA, Epstein JI. Gastrointestinal stromal tumors (GISTs) on prostate needle biopsy: A clinicopathologic study of 8 cases. Am J Surg Pathol. 2006 Nov. 30(11):1389-95. [Medline].

Hansel DE, Herawi M, Montgomery E, Epstein JI. Spindle cell lesions of the adult prostate. Mod Pathol. 2007 Jan. 20(1):148-58. [Medline]. [Full Text].

Segawa N, Hamada S, Takahara K, Azuma H, Tsuji M, Katsuoka Y. [Prostatic stromal sarcoma: a case report] [Japanese]. Hinyokika Kiyo. 2008 Jan. 54(1):29-34. [Medline].

Pan CC, Epstein JI. Common chromosomal aberrations detected by array comparative genomic hybridization in specialized stromal tumors of the prostate. Mod Pathol. 2013 Jun 14. [Medline].

Young JF, Jensen PE, Wiley CA. Malignant phyllodes tumor of the prostate. A case report with immunohistochemical and ultrastructural studies. Arch Pathol Lab Med. 1992 Mar. 116(3):296-9. [Medline].

Hansel DE, Herawi M, Montgomery E, Epstein JI. Spindle cell lesions of the adult prostate. Mod Pathol. 2007 Jan. 20(1):148-58. [Medline]. [Full Text].

Bostwick DG, Hossain D, Qian J, et al. Phyllodes tumor of the prostate: long-term followup study of 23 cases. J Urol. 2004 Sep. 172(3):894-9. [Medline].

Bannowsky A, Probst A, Dunker H, Loch T. Rare and challenging tumor entity: phyllodes tumor of the prostate. J Oncol. 2009. 2009:241270. [Medline]. [Full Text].

Colombo P, Ceresoli GL, Boiocchi L, Taverna G, Grizzi F, Bertuzzi A, et al. Prostatic stromal tumor with fatal outcome in a young man: histopathological and immunohistochemical case presentation. Rare Tumors. 2010 Dec 31. 2(4):e57. [Medline]. [Full Text].

Michaud S, Moreau A, Braud G, Renaudin K, Branchereau J, Bouchot O, et al. [Prostatic Stromal Tumors of Uncertain Malignant Potential (STUMP): definition, pathology, prognosis and management]. Prog Urol. 2012 Oct. 22(12):688-91. [Medline].

Eble JN, Sauter G, Epstein JI, Sesterhenn IA, eds. The World Health Organization Classification of Tumours: Pathology and Genetics of Tumours of the Urinary System and Male Genital Organs. Lyon, France: IARC; 2004. 209-11. [Full Text].

Lara C, Borrero JJ, Porras V, Giraldez J. [Prostatic stromal sarcoma in a 20-year-old patient] [Spanish]. Arch Esp Urol. 2005 Nov. 58(9):947-9. [Medline].

Chang YS, Chuang CK, Ng KF, Liao SK. Prostatic stromal sarcoma in a young adult: a case report. Arch Androl. 2005 Nov-Dec. 51(6):419-24. [Medline].

Probert JL, O’Rourke JS, Farrow R, Cox P. Stromal sarcoma of the prostate. Eur J Surg Oncol. 2000 Feb. 26(1):100-1. [Medline].

Morikawa T, Goto A, Tomita K, et al. Recurrent prostatic stromal sarcoma with massive high-grade prostatic intraepithelial neoplasia. J Clin Pathol. 2007 Mar. 60(3):330-2. [Medline].

Fraggetta F, Pepe P, Giunta ML, Aragona F. Primary high grade sarcoma of the specialised prostatic stroma: a case report with clinico-pathological considerations. Pathologica. 2008 Dec. 100(6):482-4. [Medline].

Huang YC, Wang JY, Lin PY, Chin CC, Chen CS. Synchronous prostate stromal sarcoma and gastrointestinal stromal tumor of rectum: case report and review of the literature. Urology. 2006 Sep. 68(3):672.e11-3. [Medline].

Janet NL, May AW, Akins RS. Sarcoma of the prostate: a single institutional review. Am J Clin Oncol. 2009 Feb. 32(1):27-9. [Medline].

Raney RB, Anderson JR, Barr FG, et al. Rhabdomyosarcoma and undifferentiated sarcoma in the first two decades of life: a selective review of intergroup rhabdomyosarcoma study group experience and rationale for Intergroup Rhabdomyosarcoma Study V. J Pediatr Hematol Oncol. 2001 May. 23(4):215-20. [Medline].

Cunha GR. Role of mesenchymal-epithelial interactions in normal and abnormal development of the mammary gland and prostate. Cancer. 1994 Aug 1. 74(3 suppl):1030-44. [Medline].

Osaki M, Osaki M, Takahashi C, Miyagawa T, Adachi H, Ito H. Prostatic stromal sarcoma: case report and review of the literature. Pathol Int. 2003 Jun. 53(6):407-11. [Medline].

Malhotra P, Bhatia A, Arora VK, Singh N. Pathologic quiz case: a 70-year-old man with bladder outflow obstruction. Prostatic stromal sarcoma. Arch Pathol Lab Med. 2004 Jun. 128(6):e81-2. [Medline]. [Full Text].

Aguilar B, Villalobos M, Sotomayor M. Phyllodes tumor of the prostate. Urology. 2009 Feb. 73(2):272. [Medline].

Hossain D, Meiers I, Qian J, MacLennan GT, Bostwick DG. Prostatic stromal hyperplasia with atypia: follow-up study of 18 cases. Arch Pathol Lab Med. 2008 Nov. 132(11):1729-33. [Medline]. [Full Text].

Rammeh Rommani S, Zermani R, Sfaxi M, Farah F, Zouari S, Chebil M, et al. [Prostatic stromal sarcoma] [French]. Prog Urol. 2006 Jun. 16(3):381-3. [Medline].

Fabio R Tavora, MD, PhD Associate Medical Director, Argos Laboratory, Visiting Scientist, Paulista Medical School, Universidade Federal de São Paulo (EPM/UNIFESP), Brazil

Fabio R Tavora, MD, PhD is a member of the following medical societies: College of American Pathologists, United States and Canadian Academy of Pathology, International Society of Urological Pathology

Disclosure: Nothing to disclose.

Pablo Furtado, MD Resident Physician in Anatomic Pathology, Department of Pathology, Universidade Federal de São Paulo (EPM/UNIFESP), Brazil

Disclosure: Received travel ticket from Merck Serono for meeting.

Liang Cheng, MD Professor of Pathology and Urology, Department of Pathology and Laboratory Medicine, Indiana University School of Medicine; Chief, Genitourinary Pathology Service, Indiana University Health

Liang Cheng, MD is a member of the following medical societies: American Association for Cancer Research, American Urological Association, College of American Pathologists, United States and Canadian Academy of Pathology, International Society of Urological Pathology, Arthur Purdy Stout Society

Disclosure: Nothing to disclose.

Acknowledgments

The authors wish to thank Dr. Esther Oliva and Dr. Marcello Franco for their encouragement and insights in this review, and Dr. Mathieu Latour, University of Montreal, for providing his expert opinion.

Pathology of Prostatic Stromal Sarcoma 

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