Mesenchymal tumors of the prostate

Primary Prostatic Stromal Sarcoma on 18 F-PSMA PET/CT

ABSTRACT

Primary prostatic stromal sarcoma is extremely rare. Serum PSA is usually normal. Here, we report a case of primary prostatic stromal sarcoma in a 23-year-old man. 18 F-prostate-specific membrane antigen (PSMA) PET/CT showed prostate mass and multiple low-density lesions in the liver with high PSMA expression. However, after chemotherapy, the level of PSMA expression in the prostate mass decreased, and PSMA expression lesions in the liver disappeared.

Analysis of three primary prostatic sarcoma cases and literature review

OBJECTIVE

The objective of this study is to evaluate the clinical presentations, diagnostic approaches, and treatment modalities for primary prostate sarcoma postradical prostatectomy, aiming to enhance its diagnosis and management.

METHODS

We retrospectively reviewed the clinical records of three male patients diagnosed with primary prostate sarcoma at Beijing Chaoyang Hospital, affiliated with Capital Medical University, from February 2014 to February 2024. All patients underwent transrectal prostate biopsies, which informed the decision to proceed with laparoscopic radical prostatectomies. After surgery, one patient received a combination of epirubicin and ifosfamide as immunotherapy, along with external beam radiotherapy. After comprehensive discussions regarding potential benefits and risks, the remaining two patients decided against undergoing radiotherapy and chemotherapy.

RESULTS

Based on the pathological examination results, two patients were diagnosed with stromal sarcoma and one with spindle cell sarcoma, all classified as high-grade sarcomas. Immunohistochemical analysis showed that all three cases were positive for VIMENTIN, but other results did not show significant specificity. During the follow-up period, one patient died within 12 months, and two patients were lost to follow-up after 6 months. However, there were no evident signs of recurrence observed during the follow-up period.

CONCLUSIONS

Primary prostate sarcoma is extremely rare and typically has a poor prognosis once diagnosed. Early diagnosis should be based on pathological and immunohistochemical testing results, followed by prompt surgical treatment and adjuvant radiotherapy and chemotherapy. Despite these measures, recurrence is common, underscoring the need for a detailed and appropriate treatment plan and systematic therapy for affected patients.

Prostatic stromal tumor of uncertain malignant potential: a case report and literature review

Prostatic stromal tumors, encompassing prostatic sarcoma and stromal tumors of uncertain malignant potential (STUMP), represent an exceedingly rare category of prostatic diseases, with a prevalence of less than 1%. We present a rare case involving a man in his early 40s diagnosed with STUMP. Despite presenting with normal prostate-specific antigen (PSA) concentrations, the patient experienced persistent dysuria and gross hematuria for >7 months, leading to an initial misdiagnosis of benign prostatic hyperplasia. Persistent symptoms prompted further investigation, with magnetic resonance imaging (MRI) revealing a suspicious lesion on the left side of the prostate, initially thought to be malignant. Transrectal prostatic biopsy subsequently confirmed the presence of mucinous liposarcoma, with no medical history of diabetes, coronary heart disease, or hypertension. The treatment approach comprised robot-assisted laparoscopic radical prostatectomy, culminating in a postoperative pathological definitive diagnosis of STUMP. This case underscores the indispensable role of early MRI in the diagnostic process, highlighting the necessity of detailed pathological examination for a conclusive diagnosis. Our report aims to illuminate the diagnostic challenges and potential treatment pathways for STUMP, emphasizing its consideration in the differential diagnosis of prostatic tumors to advance clinical outcomes in this rare but important condition.

Prostatic stromal tumour of uncertain malignant potential in a dog

An 11-year-old male Miniature Dachshund dog was presented with dyschezia. Computed tomography examination 35 days after the initial visit revealed a prostate mass (4.0 × 3.5 × 2.7 cm) and prostatectomy and orchiectomy were performed 13 days later. Grossly, the prostate was rubbery and the cut surface of the mass was swollen. The mass was whitish and demarcated from the surrounding tissues. Microscopically, the mass had a capsulate consisting of atypical spindloid stromal cells arranged in a phyllode pattern and also in a fasciculated pattern admixed with acinar ductal cells. Atypical stromal cells contained round-to-oval finely hyperchromatic nuclei that had distinct nuclei and abundant eosinophilic cytoplasm. Immunohistochemically, the atypical stromal cells were positive for vimentin, CD34, desmin, α-smooth muscle actin, progesterone receptor and androgen receptor but negative for cytokeratin AE1/AE3, p63, c-Kit, DOG-1 and SOX10. On the basis of these findings, the tumour was diagnosed as a prostatic stromal tumour of uncertain malignant potential.

Locally advanced solitary fibrous tumour of the prostate

Solitary fibrous tumours (SFTs) are rare mesenchymal neoplasms composed of spindle cells, most often occurring in the pleura. SFTs arising from the prostate are exceptionally rare, with only around 40 cases reported in literature to date. We report a man in his 60s who was referred to our clinic for elevated prostate-specific antigen and presented with mild obstructive lower urinary tract and defecatory symptoms. Prostate needle-core biopsy revealed neoplastic spindle cells that strongly expressed CD34. Cross-sectional imaging demonstrated a 12 cm locally advanced heterogeneous prostate mass with intravesical extension and mass effect on the anterior rectum. Radical cystoprostatectomy with orthotopic neobladder reconstruction was performed, and the diagnosis of primary prostatic SFT was made based on histological characteristics and immunophenotyping. We present diagnostic, clinical management and prognostic considerations in patients with primary prostatic SFT.

Prostatic stromal sarcoma: Report of a rare case in a young male and review of the literature

INTRODUCTION AND IMPORTANCE

Common prostatic neoplasms are diagnosed frequently, whereas rare entities require particular awareness and special clinical management.

CASE PRESENTATION

A 31-year-old man presented with dysuria, hematuria and urinary retention. Histomorphological analysis of material obtained by transurethral resection of the prostate initially favored a sarcomatoid carcinoma, but immunohistochemistry allowed the correct diagnosis of sarcoma of the specialized stroma of the prostate.

CLINICAL DISCUSSION

The patient refused surgical treatment and, despite chemotherapy, he died 8 months after the diagnosis. Herein, we will highlight the diagnostic and therapeutic challenge of prostatic stromal sarcoma by illustrating this case and reviewing the relevant literature.

CONCLUSION

Although rare and shadowed by more common neoplasms that may mimic it, prostatic stromal sarcoma should be considered in the differential diagnosis of bladder and prostate neoplasms because of its dismal prognosis.

A Rare Case of Prostatic Stromal Tumour of Uncertain Malignant Potential Surrounding Ejaculatory Ducts in a Patient With Concurrent Prostate Adenocarcinoma

Stromal tumour of uncertain malignant potential (STUMP) is exceedingly rare. Diagnosis and management of STUMP present a challenge to the urologist due to the absence of specific clinical findings and its unpredictable clinical course. Thus, radical resection is often recommended. Here, we present a case of a 64-year-old male, who presented with mild obstructive voiding symptoms with a raised age-specific prostate-specific antigen (PSA) of 3.1. Magnetic resonance imaging (MRI) showed an area of suspicion, in an area thought to be the left seminal vesicle, containing a malignant lesion within it. Biopsy of this area and the prostate confirmed concurrent prostatic STUMP and Gleason 3+3=6 adenocarcinoma of the prostate, managed with robotic-assisted laparoscopic radical prostatectomy with wide local excision.

Histological patterns, subtypes and aspects of prostate cancer: different aspects, different outcomes

PURPOSE OF REVIEW

The most common prostatic cancers (PCa) are acinary adenocarcinomas. Histological subtypes have been variably defined. The purpose of this review is to discuss unusual histological patterns and subtypes of acinar adenocarcinoma, as well as other types of PCa and their prognostic and therapeutic relevance.

RECENT FINDINGS

The new term 'subtype' for morphologically defined tumor entities replaced the term 'variant' in the new 2022 classification of the WHO to allow for clear terminological distinction from genetic variants. The 2022 WHO classification mentions prostatic intraepithelial neoplasia (PIN)-like carcinoma, signet-cell-like adenocarcinoma, sarcomatoid carcinoma and pleomorphic-giant-cell adenocarcinoma of the prostate as true subtypes of acinary PCa. Other forms of acinary PCa are termed unusual histological patterns and include atrophic, foamy-cell, microcystic, pseudohyperplastic and mucinous patterns. Nonacinar forms of prostate cancer include other glandular PCa, the ductal adenocarcinoma and the treatment-associated neuroendocrine carcinoma, and nonglandular PCa, the adenosquamous carcinoma, the squamous cell carcinoma and the adenoid cystic (basal cell) carcinoma of the prostate.

SUMMARY

True subtypes of acinary PCa and other forms of glandular and nonglandular PCa show relevant differences in prognosis and treatment approach compared with classic acinary PCa. The relevance of unusual histological patterns mainly lies in their deceptive benign appearance and the need for pathologists to know about these entities for accurate and timely diagnosis.

Magnetic resonance imaging features of prostatic stromal tumour of uncertain malignant potential

INTRODUCTION

Prostatic stromal tumours of uncertain malignant potential (STUMPs) are rare prostate tumours. The purpose of this study was to investigate the magnetic resonance imaging features of STUMPs.

METHODS

A total of 12 patients with STUMP confirmed with pathology who underwent MRI from 2012 to 2020 were retrospectively reviewed. Pathological characteristics including histopathology and immunohistochemistry were also recorded.

RESULTS

Among 12 STUMPs, the tumours were detected in the peripheral zone (41.7%[n = 5]) and transitional zone (58.3% [n = 7]) of the prostate. 8 cases (66.7%) were round shape. All lesions were well-defined and compressed the adjacent structures but without signs of an invasion. Homogeneous T1WI and heterogeneous T2WI signals were observed in the STUMPs. The tumours were mainly composed of solid components, while intratumoral cystic change (58.3%[n = 7]) and haemorrhage (8.3%[n = 1]) were seen. 10 cases(83.3%) were seen as relatively high DWI signal, while 2 cases(16.7%) with no increase in DWI. The mean ADC value was 1.084 ± 0.193 (range: 0.864-1.489 × 10^-3  mm² /s). STUMPs had heterogeneous enhancement, with persistent or gradual enhancement. In immunohistochemical staining, Vim, CD34, PR and SMA were positive in the majority of STUMPs.

CONCLUSION

MRI features of STUMP are presented as regular, well-defined and isolated prostatic mass with intact pseudocapsule. The presence of heterogeneous T2WI signal, intratumoral cystic change, slightly low mean ADC value and persistent or gradual enhancement may help predict the STUMPs.

Mesenchymal Neoplasms of the Prostate and Seminal Vesicles: Spectrum of Disease with Radiologic-Pathologic Correlation

There is a wide spectrum of benign and malignant mesenchymal neoplasms of the prostate, which account for less than 1% of all prostatic tumors. These include distinctive tumors that arise from the specialized prostatic stroma and site-agnostic neoplasms such as smooth muscle tumors, fibrous or myofibroblastic neoplasms, neurogenic tumors, vascular tumors, and a plethora of sarcomas. Select tumors show classic sites of origin within the prostate. While stromal tumors of uncertain malignant potential (STUMPs) commonly involve the peripheral zone at the prostate base, leiomyomas typically originate from the central prostate toward the apex. Some "prostatic" neoplasms such as gastrointestinal stromal tumors, solitary fibrous tumor (SFT), paragangliomas, and neurogenic tumors arise primarily from periprostatic soft tissues. Most mesenchymal tumors of the prostate and seminal vesicles manifest as large tumors that cause nonspecific symptoms; prostate-specific antigen level is not typically elevated. Diverse mesenchymal neoplasms demonstrate characteristic histopathologic and immunocytochemical features and variable cross-sectional imaging findings. While leiomyoma and SFT typically display low signal intensity on T2-weighted images, synovial sarcomas commonly show hemorrhage. Diagnosis is difficult because of the rarity and lack of awareness of the tumors and the significant overlap in histopathologic features. Select tumors show characteristic genetic abnormalities that allow the diagnosis to be established. For example, more than 90% of SFTs are characterized by a unique NAB2-STAT6 gene fusion, and more than 95% of synovial sarcomas are associated with a distinctive SYT-SSX chimeric transcript. Accurate diagnosis is imperative for optimal management owing to markedly different tumor biology as well as attendant therapeutic and prognostic implications. While STUMPs commonly recur, sarcomas typically charter an aggressive course with poor prognosis. Online supplemental material is available for this article. ^©RSNA, 2022.

Focal PSMA-Positive Pleural Lesion in a Patient With Stage II Prostate Carcinoma

ABSTRACT

A 70-year-old man with histopathologically proven prostate carcinoma (Gleason, 5 + 5; prostate-specific antigen level, 6.2 μg/mL) was referred for an 18F-PSMA-1007 PET/CT scan. The scan revealed bilateral PSMA uptake in the prostate, representing the primary tumor, but no evidence of PSMA-positive lymph nodes. However, a left-sided ventral pleural thickening showed focal PSMA uptake. Lesion biopsy showed no signs of malignancy, and prostatectomy was performed. The 1-year follow-up CT thorax showed growth of approximately 20% of the pleural lesion. Subsequently, video-assisted thoracic surgery of the lesion was performed. Histopathology showed a solitary fibrous tumor, a rare mesenchymal tumor.

A case of incidental STUMP discovery in a patient with concurrent prostatic adenocarcinoma

Stromal tumours of the prostate are exceedingly rare, often presenting in patients in their fifth decade of life. They are classified as either stromal sarcomas, or stromal tumours of uncertain malignant potential (STUMP), the latter of which is known to have diverse clinical behaviour and thus surgical excision is often warranted. We present a case of a 71-year-old male, initially worked up by his family doctor due to mild obstructive voiding symptoms. Following a more thorough urologic workup, including a prostate biopsy, he was found to have a markedly elevated prostate specific antigen and positive cores on prostate biopsy demonstrating prostatic adenocarcinoma. The decision was made to treat with retropubic radical prostatectomy and bilateral pelvic lymph node dissection. Resulting pathology showed concurrent prostatic adenocarcinoma in addition to STUMP. The patient continues to be followed by oncology as well as a sarcoma specialist due to the unique nature of his case.

Solitary Fibrous Tumor of the Prostate: A Case Report and Literature Review

Solitary fibrous tumors (SFTs) usually occur in the pleura and account for two-thirds of all cases; however, SFTs occurring in the prostate are extremely rare. Approximately 25 cases have been reported in the literature to date. This study reports the case of a 43-year-old man referred to our hospital with the chief complaint of a pelvic tumor after careful examination. The tumor marker levels were within normal limits. T2-weighted magnetic resonance imaging revealed a tumor, demonstrating primarily low signal intensity. It showed a capsule-like rim at the left lobe of the prostate, suggesting that the tumor was partially invading the rectal wall. Histopathological examination of needle-core biopsies showed spindle cell neoplasm with small and fusiform cells, strongly expressing signal transducer and activator of transcription 6 (STAT6) with a ramifying vascular network. Therefore, the clinical diagnosis of the patient was SFT of the prostate and robot-assisted radical prostatectomy was performed. Histopathological examination revealed that the tumor was composed of spindle cells with patternless and staghorn patterns. Immunohistochemical analysis showed a strong expression of STAT6. Furthermore, the tumor was partially positive for CD34. Therefore, the patient was diagnosed with SFT of the prostate. Two years after the initial diagnosis, the patient was alive with normal erectile function, continence status, and no evidence of the disease.

The pancancer landscape of Wnt family expression reveals potential biomarkers in urinary system tumors

Immunotherapy and targeted therapy have been particularly effective in treating tumors of the urinary system; however, the mechanisms of the Wnt family of proteins in the tumorigenesis, development, and immune response of urinary system tumors are not fully understood. Here, we show that the Wnt family was extensively upregulated in and impacted the prognosis of patients with prostate adenocarcinoma (PRAD) and bladder urothelial carcinoma (BLCA). Moreover, the Wnt family correlated with the levels of infiltrating immune cells, including B cells, CD4 + T cells, CD8 + T cells, neutrophils, macrophages, and dendritic cells. The expression levels of Wnt family members were closely related to neoantigens, the mismatch repair system (MMRS) and DNA methyltransferases, and the mutation rate was generally low. Wnt family members are potential biomarkers for precision immunotherapy of urinary system tumors.

Sarcomatoid carcinoma of the prostate with bladder invasion shortly after androgen deprivation: Two case reports

BACKGROUND

To summarize the imaging, morphological and biological characteristics of sarcomatoid carcinoma (SC) of the prostate with bladder invasion not long after castration.

CASE SUMMARY

Our two cases were initially diagnosed with adenocarcinoma of the prostate due to dysuria. However, prostate SC was diagnosed after transurethral resection of the prostate (TURP) and castration after only 5 and 10 mo, respectively. Distinctive liver-like tissues appeared in the second TURP procedure in case 1, while a white, fish flesh-like, narrow pedicled soft globe protruded from the prostate to the bladder in case 2.

CONCLUSION

The sarcomatoid component of SC may arise from one of the specific groups of cancer cells that are resistant to hormonal therapy. Morphological characteristics of SCs can present as “red hepatization” and “fish flesh”. SCs grow rapidly and have a poor prognosis, and thus, extensive TURP plus radiation may be the treatment of choice.

Imaging of non-epithelial neoplasms of the prostate

The purpose of this article is to review the spectrum of rare non-epithelial tumors of the prostate. This focused article will help the readers to understand the imaging findings of such rare entities attributed to their clinicopathological features. Radiologists must be familiar with the spectrum of non-epithelial tumors of the prostate, which helps to suggest alternate diagnosis other than adenocarcinoma, when imaging features are atypical. This is important because these tumors have different management approaches and prognoses when compared to adenocarcinoma of the prostate.

Uncommon Prostate Malignant Neoplasms

Prostate adenocarcinoma is the most common prostate cancer; however, there are several other malignant neoplasms that radiologists should be familiar with. The histological classification of malignant prostate neoplasms includes epithelial tumors, mesenchymal tumors, neuroendocrine tumors, hematolymphoid tumors, and stromal tumors. Knowledge of the main clinical and prostate magnetic resonance imaging features of uncommon tumors beyond adenocarcinoma is important for radiologists to enlarge their diagnostic ability and guide referring physician regarding the appropriate patient workup.The aim of this review article is to (1) review the main anatomical and histological concepts of the prostate gland and (2) provide an overview of uncommon prostate malignant neoplasms, emphasizing the key clinical, pathological, and imaging findings that may help radiologists in their daily interpretation of prostate magnetic resonance imaging.

Adult primary prostate sarcoma: A multi-center cohort study and comparison between Chinese and American cases

BACKGROUND/OBJECTIVES

To assess the effects of clinical factors and treatments on the overall survival (OS) of patients with prostate sarcomas.

METHODS

We reported 41 cases diagnosed with prostate sarcomas from eight hospitals in China and retrospectively analyzed the prognostic factors by combining our data with cases from five previously published cohorts, including one extra Chinese cohort and four cohorts from US cohorts. Additionally, we investigated the differences in treatment regimens between China (n = 66) and the USA (n = 74).

RESULTS

The median survival time of the 41 cases was 18.6 months (95% confidence interval [CI]: 13.9-23.2). The status of negative distant metastasis (P = 0.004) and radical tumor resection with negative margin (P = 0.001) were significantly associated with better overall survival, whereas age, tumor size, duration of initial symptoms, and chemo/radiotherapy were not significantly related to OS. The survival time was longer in patients with rhabdomyosarcoma than in those with leiomyosarcoma (P = 0.049). Combined analysis of the current and 5 prior cohorts showed that more patients in the US cohorts underwent radical surgery (P = 0.005), and the overall survival was better among those with radical cystoprostatectomy compared to those with radical prostatectomy alone (P = 0.008).

CONCLUSION

Radical resection to achieve a negative margin contributes to better survival for patients with prostate sarcoma.

Solitary Fibrous Tumor of the Prostate: A Diagnostic Challenge: A Case Report

Solitary fibrous tumor (SFT) of prostate is an unusual type of mesenchymal neoplasm that can elicit a benign or malignant phenotype. It represents a diagnostic challenge as it can simulate poorly differentiated adenocarcinoma and various mesenchymal neoplasms of prostate. We report a case of prostate SFT in a 54-year-old patient, which was clinically misdiagnosed as nodular hyperplasia of prostate with cystitis. However, on follow-up, he was not relieved by the designated treatment. Furthermore, he complained of exacerbation of symptoms and consequently, had to undergo open prostatectomy. Based on histopathological and immunohistochemical (IHC) assessment, a diagnosis of SFT of the prostate was rendered. Additionally, we have discussed the histological mimics of SFT and the diagnostic and prognostic importance of IHC while evaluating such lesions.

Solitary fibrous tumor of the seminal vesicle: A case report

RATIONALE

Solitary fibrous tumor (SFT) is an unusual neoplasm, especially when it originates from the seminal vesicle. Herein, we describe a case of SFT that arises from the seminal vesicle.

PATIENT CONCERNS

A 66-year-old man presented to our hospital complaining of a huge irregular tumor in his pelvis during a health checkup. He was worried that the tumor could be a malignant tumor and hence wanted to undergo further examination and therapy.

DIAGNOSIS

An inhomogeneous, mixed soft tissue tumor in the pelvis was found during computed tomography (CT) and magnetic resonance imaging. The tumor showed heterogeneous and delayed enhancement during contrast-enhanced CT. The tumor was diagnosed as a cystadenoma originated from the seminal vesicle due to its imaging features. But the pathological diagnosis was SFT that originated from the seminal vesicle.

INTERVENTIONS

Laparoscopic seminal vesicle tumor resection was performed.

OUTCOMES

There was no evidence of recurrence at the 6-month follow-up.

LESSONS

SFT in the seminal vesicle is extremely rare. It is very difficult to distinguish SFT in the seminal vesicle from the primary tumors as both have similar imaging features. We describe the tumor with SFT being considered as a differential diagnosis when the tumor is found in the seminal vesicle.

Complete resection of adult prostatic rhabdomyosarcoma with 3D video and printing model: A case report and literature review

Prostatic rhabdomyosarcoma (RMS) is a subtype of prostate sarcoma which is rarely reported in adults and usually huge in size. Although there is no consensus on the standard therapy to prostatic RMS, complete resection with negative margin is identified as the best way for maximum survival time. However, to remove a much enlarged prostate completely from a RMS patient is still a very difficult task for a skilled urologist so far. As three-dimension (3D) technology becomes more widely used in medicine, surgeons have the opportunity to challenge previously impossible surgery. In this paper, we reported a 36-year-old male patient with a 9.6*5.3*7.6 cm prostatic RMS. With the aid of 3D reconstructed video and printing model, the giant tumor was entirely removed without surgery complications and adjacent organs injury. The patient was alive and had no recurrence after 18 months from surgery. This case revealed that 3D reconstruction technology could help in the preoperative assessment and gave benefits to both patients and surgeons.