Spindle cell lesions of the adult prostate

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.

Leiomyosarcoma of the prostate: a novel approach to treatment-case report and review of the literature

Leiomyosarcoma of the prostate is a rare and aggressive tumor, with a quarter of the patients harboring metastatic disease, commonly in the lung. It usually presents with urinary obstruction in a relatively younger patient group. A 29-year-old male presented with lower urinary tract symptoms to the urologist. Computed tomography scan revealed a large pelvic mass involving the prostate. Biopsy on two occasions yielded leiomyoma. Instead of conventional radical surgery, en-bloc resection of the mass was done while preserving the remaining portion of the prostate, seminal vesicles, and ejaculatory duct. Histopathology revealed a high-grade leiomyosarcoma with negative margins. The patient had excellent recovery of defecation, erectile, and ejaculatory functions within 2 months after adjuvant radiotherapy. At the 24-month follow-up there was no evidence of disease. En-bloc resection of the tumor can be considered in select cases to improve functional outcomes and sustain a higher quality of life in patients.

Leiomyosarcoma of the Prostate: Report of Two Cases and Review of the Literature

Introduction

Leiomyosarcoma (LMS) of the prostate is an extremely rare and aggressive tumor that presents with nonspecific signs and symptoms. Treatment guidelines are not yet established.

Case Presentation

We report two cases of LMS of the prostate. The presenting symptom was hematuria, and diagnosis was ascertained through a transurethral resection of the prostate for the 2 patients. The treatment course consisted of three courses of chemotherapy with gemcitabine and docetaxel, radical prostatectomy, and postoperative radiation therapy for the first patient and three courses of gemcitabine and radiation therapy of the prostate and the whole pelvis for the second patient. The follow-up of our 2 patients was 9 and 12 months, respectively. Recurrence occurred 10 months after treatment completion for the second case. No recurrence was noticed in the first case.

Conclusion

These two cases highlight the importance of a multimodal approach to yield the best outcomes.

The Application and Pitfalls of Immunohistochemical Markers in Challenging Diagnosis of Genitourinary Pathology

CONTEXT.—

The morphologic features of different entities in genitourinary pathology overlap, presenting a diagnostic challenge, especially when diagnostic materials are limited. Immunohistochemical markers are valuable when morphologic features alone are insufficient for definitive diagnosis. The World Health Organization classification of urinary and male genital tumors has been updated for 2022. An updated review of immunohistochemical markers for newly classified genitourinary neoplasms and their differential diagnosis is needed.

OBJECTIVE.—

To review immunohistochemical markers used in the diagnosis of genitourinary lesions in the kidney, bladder, prostate, and testis. We particularly emphasized difficult differential diagnosis and pitfalls in immunohistochemistry application and interpretation. New markers and new entities in the 2022 World Health Organization classifications of genitourinary tumors are reviewed. Recommended staining panels for commonly encountered difficult differential diagnoses and potential pitfalls are discussed.

DATA SOURCES.—

Review of current literature and our own experience.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool in the diagnosis of problematic lesions of the genitourinary tract. However, the immunostains must be carefully interpreted in the context of morphologic findings with a thorough knowledge of pitfalls and limitations.

Seminal Vesicle Stromal Lipofuscinosis: A Rare Incidental Finding with Potential for Misdiagnosis

We report a patient with isolated stromal lipofuscinosis of the seminal vesicle, a rare entity characterized by intracytoplasmic pigmented granules within stromal cells intimately surrounding seminal vesicle epithelium. Only 4 patients with this unusual phenomenon have been previously reported in the literature. Recognizing this incidental and presumably non-pathologic finding is important to prevent misclassification as a more concerning lesion.

Leiomyoma of the Prostate Treated via Holmium Laser Enucleation: A Case Report and Literature Review

Leiomyoma is a rare tumor that arises from mesenchymal cells, with few reported cases of treatment using holmium laser enucleation of the prostate. A 74-year-old man with dysuria had a mass near the bladder neck in magnetic resonance imaging; this entity was suspected to be a leiomyoma. The patient underwent holmium laser enucleation of the prostate and one lobe was removed. However, the mass was firm and morcellation was difficult to break into small pieces. Therefore, it was fragmented via trans-urethral resection and removed with a curette. The postoperative course was favorable, with a positive clinical outcome. This case highlights the efficacy of holmium laser enucleation of the prostate in the management of prostatic leiomyoma and emphasizes its importance as a viable treatment option.

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.

Prostate sclerosing adenopathy: A clinicopathological and immunohistochemical study of twelve patients

BACKGROUND

Although sclerosing adenopathy of the prostate is a very rare benign disease, an effective differential diagnosis is required. Here, we report the clinicopathological and immunohistochemical morphological features of 12 cases of sclerosing adenopathy of the prostate to improve understanding of the disease.

AIM

To investigate the clinicopathological features, diagnosis, and immunohistochemical phenotypes that distinguish prostate sclerosing adenopathy from other conditions.

METHODS

The clinical data, laboratory tests, pathological morphology, and immunohistochemical phenotypes of 12 cases of prostatic sclerosing adenopathy were retrospectively analyzed, and the relevant literature was reviewed.

RESULTS

All patients were elderly men (mean age, 71.7 years; 62–83 years). Eleven of them had hematuria, urinary frequency, urinary urgency, difficulty in urination, and serum total prostate-specific antigen values within the normal range. One patient had increased blood pressure. Enlarged prostates with single to multiple calcifying foci were observed. Moreover, prostate tissue hyperplastic changes were observed in all patients. Small follicular hyperplastic nodules without an obvious envelope, with a growth pattern mimicking the infiltration pattern of "prostate adenocarcinoma" were noted. Basal cells expressed AR, CKH, P63, and CK5/6, and myoepithelial markers, such as calponin, S100, and smooth muscle actin. No recurrence or exacerbation of the lesions was observed, except for one case of death due to bladder cancer.

CONCLUSION

Prostatic sclerosing adenopathy is highly misdiagnosed as prostate adenocarcinoma or other tumor-like lesions. Therefore, it should attract the attention of clinicopathologic researchers.

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.

[Solitary fibrous tumor of the prostate: case report]

La tumeur fibreuse solitaire est une tumeur mésenchymateuse souvent bénigne et rare décrite pour la première fois dans la plèvre, la localisation prostatique est exceptionnelle. Nous rapportons le cas d´un patient de 77 ans qui a consulté pour symptômes du bas appareil urinaire à type de dysurie et pollakiurie. Le scanner et l´imagerie par résonance magnétique (IRM) ont montré l´origine prostatique de la lésion et précisé les rapports de cette masse avec les structures adjacentes saines, élément important pour la résécabilité de la tumeur. La biopsie transrectale avec une étude immunohistochimie ont confirmés le diagnostic, les cellules tumorales exprimaient le CD34, Bcl2 et CD 99. Le traitement était chirurgical par prostatectomie radicale.

Undifferentiated and dedifferentiated urological carcinomas: lessons learned from the recent developments

Loss of the morphological and immunophenotypic characteristics of a neoplasm is a well-known phenomenon in surgical pathology and occurs across different tumor types in almost all organs. This process may be either partial, characterized by transition from well differentiated to undifferentiated tumor component (=dedifferentiated carcinomas) or complete (=undifferentiated carcinomas). Diagnosis of undifferentiated carcinoma is significantly influenced by the extent of sampling. Although the concept of undifferentiated and dedifferentiated carcinoma has been well established for other organs (e.g. endometrium), it still has not been fully defined for urological carcinomas. Accordingly, undifferentiated/ dedifferentiated genitourinary carcinomas are typically lumped into the spectrum of poorly differentiated, sarcomatoid, or unclassified (NOS) carcinomas. In the kidney, dedifferentiation occurs across all subtypes of renal cell carcinoma (RCC), but certain genetically defined RCC types (SDH-, FH- and PBRM1- deficient RCC) seem to have inherent tendency to dedifferentiate. Histologically, the undifferentiated component displays variable combination of four patterns: spindle cells, pleomorphic giant cells, rhabdoid cells, and undifferentiated monomorphic cells with/without prominent osteoclastic giant cells. Any of these may occasionally be associated with heterologous mesenchymal component/s. Their immunophenotype is often simple with expression of vimentin and variably pankeratin or EMA. Precise subtyping of undifferentiated (urothelial versus RCC and the exact underlying RCC subtype) is best done by thorough sampling supplemented as necessary by immunohistochemistry (e.g. FH, SDHB, ALK) and/ or molecular studies. This review discusses the morphological and molecular genetic spectrum and the recent develoments on the topic of dedifferentiated and undifferentiated genitourinary carcinomas.

Differential diagnosis of uncommon prostate diseases: combining mpMRI and clinical information

The differential diagnosis of abnormalities in the prostate is broad, covering common (acinar adenocarcinoma, benign prostatic hyperplasia, chronic prostatitis, hemorrhage, cysts, calcifications, atrophy and fibrosis) and less common conditions (tumors other than acinar adenocarcinoma, granulomatous prostatitis containing tuberculosis, abscesses and other conditions, and idiopathic disorders such as amyloidosis and exophytic benign prostatic hyperplasia). Recent advances in magnetic resonance imaging (MRI) of the prostate gland and imaging guidelines, such as the Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1), have dramatically improved the ability to distinguish common abnormalities, especially the ability to detect clinically significant prostate cancer (csPCa). Overlap can exist in the clinical history and imaging features associated with various common/uncommon prostate abnormalities, and biopsy is often required but is invasive. Prostate abnormalities can be divided into two categories: category 1, diseases for which PI-RADS scores are suitable for use, and category 2, diseases for which PI-RADS scores are unsuitable for use. Radiologists must have an intimate knowledge of other diseases, especially uncommon conditions. Past relevant history, symptoms, age, serum prostate-specific antigen (PSA) levels, MRI manifestations, and the applicability of the PI-RADS assessment should be considered when diagnosing prostate abnormalities.

Prostate stromal tumor with prostatic cysts after transurethral resection of the prostate: A case report

BACKGROUND

A prostatic stromal tumor is deemed to be a rare oncology condition. Based on the retrospective analysis of clinical data and scientific literature review, a case of prostatic stromal tumor was reported in this article to explore the diagnosis, treatment and prognosis of this rare disease.

CASE SUMMARY

The present case involved an older male patient who was admitted to our department for a medical consultation of dysuria. Serum prostate-specific antigen was 8.30 ng/mL, Ultrasound and magnetic resonance imaging suggested evident enlargement of the prostate and multiple cystic developments internally. Considering that the patient was an elderly male with a poor health status, transurethral resection of the prostate was performed to improve the symptoms of urinary tract obstruction. Furthermore, based on histopathologic examination and immunohistochemical staining, the patient was pathologically diagnosed with prostatic stromal tumor. The patient did not receive any further adjuvant therapy following surgery leading to a clinical recommendation that the patient should be followed up on a long-term basis. However, during the recent follow-up assessment, the patient demonstrated recurrence of lower urinary tract symptoms and gross hematuria.

CONCLUSION

Referring to scientific literature review, we believe that the management of these lesions requires a thorough assessment of the patient. Furthermore, the treatment of prostate stromal tumors should be based on the imaging examination and pathological classification. Active surgical treatment is of great significance to the prognosis of patients, and subsequent surveillance after the treatment is warranted.

Prostatic stromal proliferations: a review

Prostatic stromal proliferations account for the majority of benign tumour-like lesions in the prostate. The most common is nodular hyperplasia, seen in a majority of elderly men. Diagnostic difficulty is encountered with some variants, including stromal hyperplasia with atypia, characterised by degenerative changes of myofibroblasts. In contrast with benign stromal tumours, malignant stromal tumours of the prostate are rare, accounting for less than 0.1% of all prostatic malignancies. The most common are rhabdomyosarcoma (paediatric) and leiomyosarcoma (adults); others include phyllodes tumour and stromal sarcoma. Some authors lump malignant tumours with poor outcome (e.g., phyllodes tumour and stromal sarcoma) with benign stromal tumours (e.g., stromal hyperplasia with atypia, leiomyoma), considering them collectively to be of uncertain malignant potential, but this approach is discouraged. This review presents a contemporary approach to classification and diagnosis of prostatic stromal tumours.

Case of prostate stromal tumour of uncertain malignant potential where positron emission tomography with 18F-fluorodeoxyglucose was useful for surgical planning

Stromal tumour of uncertain malignant potential of the prostate is a rare tumour with a variable clinical behaviour ranging from incidentally detected indolent tumours that never progress, to aggressive diseases almost identical to sarcomas that may invade surrounding organs or develop metastases. Surgical excision is generally recommended for local diseases; however, owing to its diverse clinical outcomes, optimal management may vary from surgery alone to wide excision combined with chemotherapy and/or radiotherapy. Therefore, preoperative evaluation of the malignant potential of the disease is essential to decide the treatment strategy. Herein, we report a case of stromal tumour of uncertain malignant potential successfully treated with minimally invasive robot-assisted radical prostatectomy alone under the diagnosis of the disease with low malignant potential based on the findings of positron emission tomography with 18F-fluorodeoxyglucose.

Primary Gastrointestinal Stromal Tumor of the Prostate: Unexpected Guest

Primary mesenchymal lesions of the prostate are exceptionally rare. They comprise 1% of all prostatic neoplasms. Despite its rare location, the diagnosis of primary gastrointestinal stromal tumors (GISTs) of the prostate gland should never be missed. Such a diagnosis can be made after the rolling out of direct extension from adjacent organs, especially the rectum. GIST diagnosis has a clinical impact on patient treatment and clinical outcomes. They harbor a certain KIT activation mutation that responds to pharmacologic therapy inhibitors.

The objective of the current study was to provide a thorough review of GIST arising primarily in the prostate gland along with a comprehensive study of GIST pathogenesis, histologic morphology, immunohistochemistry, and molecular studies’ findings, and their importance in differentiating GIST from other prostate mesenchymal tumors. This will emphasize the role of careful spindle cell lesion diagnosis in the prostate gland that can influence the prognostic stratification of clinical management, future follow-up, and disease outcome.

Thirteen cases were collected after an extensive and detailed review of the English literature through PubMed, Medknow, Google Scholar, as well as personal experience.

The anatomic location of this lesion plays a significant role in the differential diagnosis. It is difficult to establish the accurate primary origin of GIST on core needle tissue biopsy. Thus, clinical, and radiological examinations play a crucial role in rolling out the possibility of rectal GIST secondarily invading and involving the prostate gland.

To conclude, primary prostatic GIST is a rare diagnosis. Extraintestinal, particularly rectal, GIST can clinically and radiologically mimic the impression of the prostatic lesion. Before diagnosing primary prostatic spindle cell lesions, such as solitary fibrous tumor (SFT), inflammatory myofibroblastic tumor (IMT), leiomyoma, leiomyosarcoma, or prostatic stromal tumors, one should include CD117/c-Kit in the workup of a prostatic spindle cell lesion. GIST has distinct pathogenesis, and its diagnosis can have a clinical impact on the patient's management plan and clinical outcome.

Prostate preserving resection of a rare giant peri-prostatic solitary fibrous tumor

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms that have been infrequently documented in the prostate. In this case, a 78 year old man experiencing constipation and lower abdominal pain presented with a SFT arising from the prostatic fascia encompassing the dorsal vein complex and left neurovascular bundle. To our knowledge this is the first documented case of an SFT limited to the prostatic fascia and neurovascular tissues of the prostate. Using a prostate sparring approach we have been able to achieve favourable oncological and functional outcome.

Clinicopathological features to distinguish malignant solitary fibrous tumors of the prostate from prostatic stromal tumors

Mesenchymal tumors of the prostate are rare but encompass a wide differential diagnosis. In our study, we aimed to investigate the clinicopathological features that can be used to differentiate malignant solitary fibrous tumors (mSFTs) occurring in the prostate from prostatic stromal tumors. A total of 15 patients with mesenchymal tumors of the prostate were identified in Nanjing Drum Tower Hospital from 2009 to 2019, including 3 mSFTs, 9 stromal tumors of uncertain malignant potential (STUMPs), and 3 prostatic stromal sarcomas (PSSs). Immunohistochemical stains for signal transducer and activator of transcription 6 (STAT6), aldehyde dehydrogenase 1 (ALDH1), CD34, desmin, smooth muscle actin (SMA), progesterone receptor (PR), CD117, and cytokeratin (CK) were performed on representative sections from each tumor, and the clinical features, histology, and immunophenotype of these three groups were analyzed. There was no significant difference in mean patient age of patients diagnosed with mSFTs, STUMPs, and PSSs. mSFTs and PSSs showed significantly increased tumor size (p < 0.05), Ki-67 proliferation index (p < 0.0001), and mitotic activity (p < 0.05) when compared with STUMPs. mSFTs showed significantly higher expression of STAT6 compared with both PSSs and STUMPs (p < 0.0001, p < 0.0001). PR showed significantly more expression in STUMPs than in mSFTs or PSSs (p < 0.0001, p < 0.0001). Desmin and SMA showed significantly more expression in STUMPs than in mSFTs (p < 0.05). ALDH1, CD117, CK, and CD34 showed no significant difference in staining between mSFTs, STUMPs, and PSSs. Therefore, a limited panel of STAT6, PR, and Ki-67 may be useful in distinguishing between mSFTs, STUMPs, and PSSs.

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.

Iatrogenic Disease of the Genitourinary Tract

Iatrogenic disease is defined as illness caused by diagnostic procedures or treatment given by health care professionals. More recently described treatment complications involving the genitourinary tract include newly recognized variants of renal carcinoma in the setting of dialysis/end-stage renal disease, treatment effect in genitourinary carcinomas, and medical renal disease caused by drug therapies, including immunotherapy. The objective of this review is to cover iatrogenic inflammatory diseases, pseudotumors and tumors of the kidney, bladder, prostate, testis and paratestis of most interest to surgical pathologists. For this reason, disease caused by the following will not be covered: iatrogenic glomerulonephritis, self-inflicted injury including the introduction of foreign bodies, surgical error, drugs of abuse and herbal medications, and iatrogenic disease in the transplant setting including ischemia/reperfusion injury. Emphasis is placed upon commonly encountered diseases in order to ensure that the review is of utility to practicing pathologists. The clinical context, pathophysiology and histopathology of each disease entity are covered.

Targeting phenotypic heterogeneity in benign prostatic hyperplasia

Benign prostatic hyperplasia and associated lower urinary tract symptoms remain difficult to treat medically, resulting in hundreds of thousands of surgeries performed annually in elderly males. New therapies have not improved clinical outcomes since alpha blockers and 5 alpha reductase inhibitors were introduced in the 1990s. An underappreciated confounder to identifying novel targets is pathological heterogeneity. Individual patients display unique phenotypes, composed of distinct cell types. We have yet to develop a cellular or molecular understanding of these unique phenotypes, which has led to failure in developing targeted therapies for personalized medicine. This review covers the strategic experimental approach to unraveling the cellular pathogenesis of discrete BPH phenotypes and discusses how to incorporate these findings into the clinic to improve outcomes.

Multiparametric magnetic resonance imaging findings of prostatic pure leiomyomas

OBJECTIVE:

To describe the imaging findings of prostatic tumors nonadenocarcinoma on multiparametric magnetic resonance imaging.

METHODS:

A total of 200 patients underwented multiparametric magnetic resonance imaging of the prostate for screening for prostate cancer, from August 2013 to September 2014, followed by biopsy with ultrasound/magnetic resonance imaging fusion.

RESULTS:

We found three pathologic proved cases of prostatic pure leiomyomas (0.02%) in our series and described the multiparametric magnetic resonance imaging features of these prostatic leiomyomas. The imaging findings had similar features to lesions with moderate or high suspicion for significant cancer (Likert 4 or 5) when localized both in the transitional zone or in the peripheral zone of the gland.

CONCLUSION:

Pure prostatic leiomyomas had imaging findings on multiparametric magnetic resonance imaging that mimicked usual adenocarcinomas on this test. Radiologists, urologists and pathologists must be aware of this entity and its imaging features.

OBJETIVO:

Descrever os achados de imagem de tumores prostáticos não adenocarcinoma na ressonância magnética multiparamétrica.

MÉTODOS:

Realizaram ressonância magnética multiparamétrica da próstata para detecção de câncer de próstata 200 pacientes de agosto de 2013 a setembro de 2014, seguida por biópsia com fusão de imagens de ultrassonografia/ressonância magnética.

RESULTADOS:

Encontramos três casos confirmados histologicamente de leiomiomas prostáticos puros (0,02%) em nossa casuística e descrevemos os achados da ressonância magnética multiparamétrica destes casos de leiomiomas. Os achados de imagem foram semelhantes aos de lesões com moderada ou alta suspeição para neoplasia clinicamente significante (Likert 4 ou 5) quando localizados na zona de transição ou zona periférica da próstata.

CONCLUSÃO:

Leiomiomas puros da próstata tiveram achados de imagem na ressonância magnética multiparamétrica que mimetizaram adenocarcinomas. Radiologistas, urologistas e patologistas devem estar cientes destas entidades e seus achados de imagem.

Leiomyosarcoma of the prostate-an unexpected histopathological outcome

Prostate leiomyosarcoma is an extremely rare and highly aggressive neoplasm that accounts for >0.1% of all primary prostate malignancies. We report a case of a patient, presenting with recurrent episodes of dysuria, who had been diagnosed and operated for benign prostatic hyperplasia 1 month earlier, and now presented with similar symptoms postoperatively. Trans-rectal biopsy of the prostate was carried out and histopathology revealed leiomyosarcoma of the prostate.

Long term follow-up of surgery management of prostate leiomyosarcoma metastasized to the rib: A case report and literature review

Prostate sarcoma, particularly the pathological type of leiomyosarcoma, is a rare carcinoma, which originated from the interstitial tissue of the prostate. This sarcoma type has a poor prognosis. This disease accounts for ~0.1% of all prostate cancer and it usually occurrs in patients aged between 40 and 78-years-old. Although prostate leiomyosarcoma has a poor prognosis, early treatment of post-operative recurrence and metastases via a whole-body examination and closer follow-up was possible. These measurements may significantly prolong the survival time and improve the quality of life. The present study reported a successful case of surgical management for prostate leiomyosarcoma in the Zigong No. 4 People's Hospital (Sichuan, China) during 1995 until 2015, with post-operative follow-up for 20 years.

Is it really an abscess? An unusual case of metastatic stromal cell sarcoma of the prostate

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Prostatic stromal sarcomas account for about 0.1% of all prostatic malignancies.

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The preferred treatment is surgery by radical prostatectomy or cystoprostatectomy.

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Local recurrence occurs in to bladder, seminal vesicles and rectum.

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Distal metastasis, has so far only been reported in lung and bone.

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Subcutaneous metastasis of a prostatic stromal cell sarcoma has not been reported before.

Introduction

Prostatic stromal sarcomas account for about 0.1% of all prostatic malignancies. Local recurrence into bladder, seminal vesicles and rectum has been documented. Distal metastasis, has so far only been reported in lung and bone.

Presentation of case

We report the case of a 42 year old man with a subcutaneous metastatic deposit of a prostatic stromal cell sarcoma 5 years after radical prostatectomy. Additional staging with CT- and PET-scan showed lymph node involvement in the neck and left axilla. A core biopsy of the skin lesion was undertaken, of which the histology revealed a low grade spindle cell tumour that was morphologically identical to a previously diagnosed prostatic stromal sarcoma.

Discussion

In literature distant metastases to the lung and bone have been documented before. This is the first documented case of a subcutaneous metastasis of prostatic stromal cell sarcoma.

Conclusion

The preferred treatment for prostatic stromal cell sarcoma is surgery by radical prostatectomy or cystoprostatectomy. There is currently not enough literature on the topic to elucidate the role of chemo- or radiotherapy in loco-regional or distant spread.

A Review of the Literature on Primary Leiomyosarcoma of the Prostate Gland

Primary leiomyosarcoma of the prostate (PLSOP) is rare, with less than 200 cases reported so far. PLSOPs present with lower urinary tract symptoms, haematuria, and perineal pain; may or may not be associated with a history of previous treatment for adenocarcinoma of prostate by means of radiotherapy and or hormonal treatment; may afflict children and adult male. Examination may reveal benign enlarged prostate and hard enlarged mass. PLSOPs may be diagnosed by histological examination findings of spindle-shaped carcinoma cells in prostate specimens. Immunohistochemical staining tends to be positive for vimentin, CD44, smooth muscle actin, and calponin, focally positive for desmin, and at times positive for keratin. They stain negatively for PSA, S-100, CD34, CD117, and cytokeratin. Cytogenetic study on primary leiomyosarcoma of the prostate gland may show clonal chromosomal rearrangement involving Chromosomes 2, 3, 9, 11, and 19. On the whole the prognosis is poor. Surgery with or without chemotherapy would appear to be the mainstay of treatment for PLSOPs that are operable, but generally there is no consensus opinion on the best therapeutic approach. Most cases of PLSOPs are diagnosed in an advanced stage of the disease. A global multicenter trial is required to find therapies that would improve the prognosis.

Pseudohyperplastic variant of adenocarcinoma as a component of α-methyl-CoA-racemase (AMACR negative) carcinosarcoma of the prostate

Carcinosarcoma (CS) or Sarcomatoid carcinoma (SC) of the prostate is a very rare malignant tumor of the prostate having an aggressive clinical course and dismal prognosis. The adenocarcinomatous element is usually of the acinar type and closely admixed with a sarcomatous component. We report a case of α-methyl–CoA-racemase (AMACR)-negative pseudohyperplastic variant of adenocarcinoma in CS. To the best of our knowledge, there have been no published case reports of this variant in CS till date. An accurate diagnosis is essential as this uncommon, aggressive cancer has limited therapeutic options

Stromal tumor of uncertain malignant potential of the prostate

Stromal tumor of uncertain malignant potential (STUMP) of the prostate is a rare tumor with a variable and unpredictable clinical course. Many STUMPs are diagnosed incidentally and never progress, while others may invade locally and rapidly recur after surgical intervention, and yet others may lead to distant metastasis and death. A wide array of histologic patterns is encompassed by STUMP, and distinguishing these tumors from prostatic stromal sarcoma or other causes of stromal expansion often proves difficult. Owing to the rarity of this tumor, there is not yet a consensus on appropriate management. However, owing to the possibility of aggressive behavior, close management and consideration of definitive resection is warranted.

Diagnosis of a gastrointestinal stromal tumor presenting as a prostatic mass: a case report

Gastrointestinal stromal tumors (GISTs) are an unusual and heterogeneous group of spindle cell tumors that can also appear on the exterior of the gastrointestinal tract (extra-GISTs). Despite the fact that extra-GISTs or large rectal GISTs can lead to the clinical impression of a prostatic mass, these tumors are, in general, excluded in the differential diagnosis of spindle cell tumors observed on prostate needle biopsy. Here, we present, in detail, a case of an extra-GIST identified on prostatic biopsy; the tumor was previously believed to be a primary prostatic stromal sarcoma in the differential diagnosis. Every investigator should check for KIT (CD117) in immunohistochemical staining to rule out an extra-GIST prior to diagnosing a solitary prostatic tumor, specialized prostatic stromal tumor, or leiomyosarcoma on prostate needle biopsy.

The history of calculus mendax and the following surgery on the prostate

In this paper we would like to present probably the first surgery performed on the prostate gland followed by microscopic analysis of the obtained tumor tissue sample. We based on the existing correspondence between Ludwig von Hammen and Johann N. Pechlin, and their successors in this field as well. Von Hammen seems to be a pioneer in the area of not only urological surgery but in directing this part of medical practice from "lithotomists" to physicians, much better educated than barbers in physiology but first of all in anatomy. This 17th century physician from Gdansk tried to set new standards both for surgical medical practice but histopathological examination of the excised material as well. Due to the change of the operational skills and procedures von Hammen's work got almost forgotten, but remains remembered due to the work of historians of the medicine from following centuries.

Primary gastrointestinal stromal tumor of the prostate: A case report and literature review

Extragastrointestinal stromal tumors (EGISTs) are relatively rare soft tissue neoplasms arising from the extra gastrointestinal tract. The current study presents a case of primary EGIST of the prostate observed in a 55-year-old male. Imaging studies showed a 10×10.5×9.5-cm prostate mass. On histological observation, the mass was separated from the rectum serosa and exhibited a high mitotic count (8/50 high-power fields). The results of immunohistochemical staining showed positive immunoreactivity for cluster of differentiation (CD)117 (c-kit), CD34 and DOG1 in the tumor. On mutation analysis, loss of heterozygosity of the c-kit gene was observed in the prostatic EGIST; however, the platelet-derived growth factor receptor-α (PDGFRA) gene was considered to be normal. Therefore, as EGIST of the prostate is rare, there is a requirement for the confirmation of the diagnosis to be based on immunohistochemistry and mutation analysis (of c-kit and PDGFRA).

Complex cellular composition of solitary fibrous tumor of the prostate

Solitary fibrous tumors (SFTs) of the prostate are a rare type of spindle cell neoplasm that can demonstrate either a benign or malignant phenotype. SFTs represent a clinical challenge along with other spindle cell lesions of the prostate in terms of both diagnosis and treatment. The present study shows, for the first time, that SFTs of the prostate and other organs can comprise a mixed population of fibroblast, myofibroblast, and smooth muscle cell types. The highly proliferative component demonstrated a fibroblastic phenotype that readily underwent myofibroblast differentiation on exposure to profibrotic stimuli. Consistent with other recent studies, the prostatic SFTs demonstrated NAB2-STAT6 gene fusions that were also present in the fibroblast, myofibroblast, and smooth muscle cell types of the SFT. The results of these studies suggest that benign and malignant prostatic tumors of mesenchymal origin may be distinguished at the molecular and cellular levels, and that delineation of such defining characteristics may help elucidate the etiology and prognosis of such tumors.

Sarcomatoid carcinoma of prostate involving the whole lower urinary tract and rectum

Sarcomatoid carcinoma of prostate is an extremely rare but aggressive neoplasm. It is generally associated with a poor prognosis. About 100 cases have so far been reported in the English literature. We report the case of a 64-year-old male with a very rapidly progressive disease that ultimately involved the whole lower urinary tract and rectum. The management of this case along with etio-pathogenesis and literature review is discussed.

Prostatic carcinosarcoma with lung metastases

Carcinosarcoma of the prostate is an uncommon malignancy with poor long-term prognosis. The cancer is typically discovered at an advanced stage, and with less than 100 reported cases, there is limited literature concerning treatment options. Our patient presented with a history of benign prostatic hypertrophy, erectile dysfunction, and nocturia. Biopsy of his prostate indicated that the patient had prostatic adenocarcinoma, but histopathology after prostatectomy revealed carcinosarcoma. It has been over six years since this patient's diagnosis of carcinosarcoma. Over this span of time, he has received a radical prostatectomy, radiotherapy, and androgen ablative therapy. The patient also developed multiple lung metastases that have been treated with video-assisted thoracic surgery and stereotactic body radiosurgery. Overall, he has remained unimpaired and in good condition despite his aggressive form of cancer.