Diagnostic dilemmas of squamous differentiation in prostate carcinoma case report and review of the literature

Mixed Adenosquamous Cell Carcinoma of the Prostate with Paired Sequencing on the Primary and Liver Metastasis

This report aims to shed light on the intricate challenges encountered during the diagnosis and treatment of an uncommon variant of prostate cancer-mixed adenosquamous cell carcinoma of the prostate. Prostate cancers of this nature pose distinctive diagnostic and therapeutic dilemmas due to their rarity and complex histological composition. We present a case of a 63-year-old man with metastatic prostate cancer, featuring adenocarcinoma with squamous cell differentiation, who underwent a multimodal treatment approach. The patient responded to first-line carboplatin, docetaxel, and androgen deprivation therapy, followed by androgen receptor pathway inhibitor (ARPI) maintenance. However, disease progression led to radiation therapy and a subsequent switch to Lutetium (177Lu) vipivotide tetraxetan after chemotherapy challenges. Comprehensive genetic profiling revealed shared mutations in the prostate and liver lesions, emphasizing the role of targeted therapies. Prostate-specific membrane antigen (PSMA)-targeted therapy resulted in a notable PSA decline. This case highlights the evolving treatment landscape for rare prostate cancers, integrating genetic insights for tailored interventions. In conclusion, squamous cell carcinoma (SCC) of the prostate is rare, emphasizing the imperative for enhanced comprehension in diagnosis and management. Our case suggests the potential efficacy of ARPI and PSMA-targeted therapies. Our findings advocate for a more nuanced approach to the management of this rare prostate cancer variant, leveraging genomic insights for personalized treatment strategies. This exploration serves as a foundation for further research and clinical considerations in addressing the challenges posed by mixed adenosquamous cell carcinoma of the prostate.

Post-therapeutic squamous cell transformation of a metastatic prostate adenocarcinoma with comparison of molecular profiles: a case report and review of the literature

Transformation of primary prostate adenocarcinoma to squamous cell carcinoma after initial treatment with chemotherapy and hormonal therapy is extremely rare and typically results in rapid treatment-refractory disease progression and death. Here, we present a case of a 64-year-old man who was initially diagnosed with metastatic prostate adenocarcinoma (positive PSA and NKX3.1 stains, total PSA 747.2 ng/ml) to the thoracic spine (T8) in 2019. The patient received androgen deprivation therapy and chemotherapy with good response (PSA 2.53 ng/ml). In 2022, the patient had a tumor resection from the left humerus with a consequent fracture. Pathology showed pure squamous carcinoma without any adenocarcinoma component (PSA and NKX3.1 stains negative and weak p504s stain, PSA 19.82 ng/ml). Given the patient's history of metastatic prostate adenocarcinoma and no history of any other malignancies, a diagnosis of squamous carcinoma transformed from prostate adenocarcinoma was rendered. The patient passed away in 2023. Molecular profiling identified the same TP53 mutation and two variants of uncertain significance in both specimens, suggesting the same primary. However, there was CCND3 amplification and absence of the TMPRSS2::ETV4 fusion in the 2022 specimen, which may be associated with squamous transformation and poor prognosis. A microarray might be beneficial to confirm loss of the TMPRSS2::ETV4 fusion. This case illustrates the rare occurrence of squamous transformation in prostate adenocarcinoma and the aggressive clinical course, and need for more therapy guidance and prognostic studies. It also highlights the importance of molecular profiling to provide insights into the pathogenesis of histologic transformation.

Primary Adenosquamous Carcinoma of the Prostate With Multiple Heterogenic Metastases Demonstrated on 68 Ga-PSMA and 18 F-FDG PET/CT Imaging

ABSTRACT

A 54-year-old man presented with a 2-month history of urination disturbances. Serum prostate-specific antigen level was 4.96 ng/mL, and a possibility of benign prostate hyperplasia was raised by outside medical CT. Histopathology revealed adenosquamous carcinoma. Staging workup showed large areas of high PSMA uptake and focal intense hypermetabolism in the prostate, multiple lymphatics, bone, and pulmonary heterogenic metastases on 68 Ga-PSMA and 18 F-FDG PET/CT imaging.

Beyond the norm: exploring the uncommon squamous cell carcinoma of the prostate using a Saudi tumor registry

Background

Squamous cell carcinoma (SCC) of the prostate has limited treatment choices and portends a dismal prognosis with an average survival time of ~14-months. This study provides a descriptive overview of SCC of the prostate in Saudi Arabia.

Materials and Methods

A retrospective cohort study of patients diagnosed with prostatic SCC between 1 January 2008 and 31 December 2017. Information on demographic and tumor characteristics and the survival of patients was collected from the Saudi Cancer Registry. Survival was depicted through Kaplan-Meier plots. Fisher's exact test was used to assess the association between categorical variables and death, while a Wilcoxon rank sum test was applied for numerical variables.

Results

Out of a larger subset of 3607 patients, 16 patients were diagnosed with prostatic SCC, of which half resided in the Central region (50.0%) and most (81.2%) were aged greater than or equal to 60 years. Most patients (62.6%) had poorly differentiated (grade III, 43.8%) lesions, and 50% of cases were metastatic at diagnosis. 62.5% of patients died, all residing in the Eastern and Central regions. Regional extension (75.0%) and distant metastasis (87.5%) were significantly associated with death compared to localized lesions (0.0%) (P=0.022). The 5-year survival rate in our study was 33%.

Conclusion

The present study is the first to describe the characteristics of prostatic SCC in Saudi Arabia. Our results are consistent with prior studies showing that prostatic SCC is often high-grade and metastatic at diagnosis, conferring a poor prognosis.

Oligometastatic Squamous Cell Transformation From Metastatic Prostate Adenocarcinoma Treated With Systemic and Focal Therapy: A Case Report

Transformation to squamous cell carcinoma (SCC) after initial treatment of a primary prostate adenocarcinoma is rare and typically results in rapid treatment-refractory disease progression and death. Here, we present a case of a 70-year-old man who was initially treated with prostatectomy and radiotherapy, and later developed bone metastases. After commencing systemic therapy with androgen deprivation therapy (ADT) and apalutamide, his prostate-specific antigen (PSA) declined to undetectable levels, yet short-interval imaging demonstrated oligo-progression at T4, with biopsy specimen demonstrating pure SCC. Molecular profiling of both the primary prostate tumor and T4 demonstrated alterations in TMPRSS2-ERG, TP53, and FOXA1 confirming site of origin, with loss of RNF43 in the squamous metastasis. He was treated with stereotactic body radiation therapy to the SCC metastasis and continued on ADT and apalutamide with stable disease for a year post-radiation. This case highlights the importance of imaging to detect non–PSA-producing metastatic disease, the utility of radiation therapy in oligo-progression, and use of molecular profiling to provide insights into the pathogenesis of histologic transformation.

Challenge and Outcome for the Prostate Squamous Cell Carcinoma Which Developed 8 Years after Low-Dose-Rate Brachytherapy Approached by a Combined Multimodal Treatment with High-Dose-Rate Interstitial Brachytherapy, External Beam Radiation Therapy, and Chemotherapy

Prostate squamous cell carcinoma (pSCC) rarely develops as a secondary cancer after treatment with low-dose-rate brachytherapy (LDR-BT). There is no established effective treatment for the disease condition. Herein, we present a 78-year-old man who developed pSCC 8 years after LDR-BT. He was subsequently selected to receive a combined multimodal treatment with high-dose-rate interstitial brachytherapy (HDR-ISBT), external beam radiation therapy, and chemotherapy for his pSCC. Eleven months later, he displayed no biochemical failure nor clinical radiographic recurrence. However, MRI detected a newly developed prostatic-rectal fistula (grade 4), and a colostomy was performed to relieve pain and inflammation. To our knowledge, this is the first report to perform a combined multimodal treatment with HDR-ISBT for pSCC suspected as a secondary cancer due to LDR-BT.

Histological and immunohistochemical investigation of canine prostate carcinoma with identification of common intraductal carcinoma component

A limited number of species, including men and dogs, spontaneously develop prostate cancer (PC). The histological and molecular relevance of canine PC as a model for the disease in men remains controversial. To address this challenge, this study aimed to assess the histomorphology and expression of basal cell, urothelial and neuroendocrine markers [p63, high molecular weight cytokeratin (HMWCK), Uroplakin 3 (UPIII), neuron‐specific enolase (NSE)] in canine PC (n = 41). Based on histomorphology, 10/41 (24%), 21/41 (51%) and 9/41 (22%) were classified as adenocarcinoma (AC), urothelial carcinoma (UC), and mixed carcinoma, respectively. Tumour inflammation was common, frequently severe [20/41 (49%)], and associated with neutering (p < .02) and urothelial differentiation (p < .02). Most (36/40, 90%) cancers contained only rare cells with basal cell marker expression or were negative. The expression of UPIII was absent or weak in the majority (33/38, 87%) of tumours, with moderate to strong staining in the remaining cases. NSE expression in PC was rare and limited to 2/14 (14%) cases. Tumour extension into benign ducts and glands was a common finding with presence in 17/39 (44%) of carcinomas with and without urothelial differentiation. In conclusion, we confirm that canine PC is characterized by absent or weak expression of basal cell and urothelial markers. Although rare, NSE expression, potentially indicating neuroendocrine differentiation, is reported for the first time in canine PCa. Intraductal carcinoma of the prostate with concurrent invasive PCa (IDCP‐inv) is a frequent, not previously described, finding in dogs with PC.

Patterns of Care and Treatment Outcomes in Locoregional Squamous Cell Carcinoma of the Prostate

Primary squamous cell carcinoma is a rare, aggressive disease with historically poor outcomes and no established treatment guidelines. Case reports are limited but describe multiple treatment approaches. Seeking to identify practice patterns and treatment outcomes, we used the US National Cancer Data Base to identify 66 males with locoregional primary squamous cell carcinoma of the prostate treated with surgery, chemotherapy, and/or radiotherapy between 2004 and 2015. Patients were stratified into treatment groups consisting of local therapy alone (n = 40; 61%), local therapy and chemotherapy (n = 13; 20%), chemotherapy alone (n = 7; 11%), and observation (n = 6; 9%). Patients with clinical stage T3–T4 disease were significantly more likely to receive combined chemotherapy and local therapy on multivariable analysis. Median survival was 20 mo for patients treated with local therapy alone, 37 mo with local therapy and chemotherapy, and 11 mo with chemotherapy alone. Overall survival was not significantly different between treatment groups. Despite limitations in sample size, these data suggest that addition of chemotherapy to local therapy is a reasonable treatment approach for select patients.

Patient summary

Squamous cell carcinoma of the prostate is an extremely rare disease. Our review of patterns of care using data from the National Cancer Data Base shows inconsistent use of combined local and systemic therapy. The small sample size for this rare disease limits any conclusions regarding survival differences, but the data suggest that a combination approach using chemotherapy in addition to surgery or radiation is a reasonable treatment option for disease confined to the prostate.

Primary prostatic squamous cell carcinoma

Primary prostate squamous cell malignancies are rare and very aggressive. A 65-year-old man presented to our institution with clinical and radiographic findings concerning for advanced prostatic malignancy. Surgical pathology of the tumor revealed poorly differentiated carcinoma with squamous differentiation, and histopathological markers were positive for markers of squamous differentiation negative for all urothelial and prostatic markers.

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.

Metastatic squamous cell carcinoma transformed from prostatic adenocarcinoma following androgen deprivation therapy: A case report with clinicopathologic and molecular findings

Squamous cell carcinoma (SCC) of the prostate is a rare and clinically aggressive entity that may arise de novo or through transformation of prostatic adenocarcinoma, typically following hormonal or radiation therapy. Confirmation of prostatic origin, especially when evaluating a metastatic focus, often requires correlation with clinical and imaging findings, as the morphologic and immunohistochemical features of SCC are not organ-specific. Comprehensive genomic profiling (CGP) may provide additional information useful for confirming the primary site and for identifying potential targeted therapy options. CGP data may also contribute to our understanding of the molecular basis of squamous differentiation in prostatic malignancies. However, these data are limited, and to our knowledge, there are only three previously published cases of prostatic SCC with reported CGP findings. Herein, we report a case of metastatic keratinizing SCC diagnosed by core needle biopsy in a 68-year-old man with a history of prostatic adenocarcinoma status post radical prostatectomy and androgen deprivation therapy (ADT). NKX3.1 immunohistochemistry was negative. CGP was performed, and a TMPRSS2-ERG fusion, among other genetic alterations, was detected, supporting a diagnosis of metastatic SCC transformed from prostatic adenocarcinoma following ADT. This case supports the use of CGP or other molecular techniques not only to query potential targeted therapy options but also to refine the diagnosis and confirm the primary site of disease in cases with non-specific morphologic and immunophenotypic features, such as SCC.

Prostate squamous cell carcinoma developing 11 years after external radiotherapy for prostate adenocarcinoma

INTRODUCTION

Secondary bladder, colon, and rectal cancers are relatively common after prostate radiotherapy. However, secondary squamous cell carcinoma of the prostate is rare.

CASE PRESENTATION

An 85-year-old man presented with dysuria and low-serum prostate-specific antigen levels. His medical history included localized prostate adenocarcinoma (Gleason score of 4 + 5) treated with combined three-dimensional conformal radiotherapy and androgen deprivation therapy, 11 years ago. Urethroscopy and magnetic resonance imaging showed a bulging mass around the prostatic urethra. Transurethral resection of the prostate performed for histopathological diagnosis revealed squamous cell carcinoma.

CONCLUSION

Hereby, a rare case of secondary squamous cell carcinoma of the prostate after radiotherapy for adenocarcinoma was reported, which was found after 11 years of radiotherapy with symptom of dysuria including urinary hesitancy, difficulty, pain during urination, and low-serum prostate-specific antigen levels.

European Association of Urology Guidelines on Primary Urethral Carcinoma-2020 Update

CONTEXT

Primary urethral carcinoma (PUC) is a rare cancer accounting for <1% of all genitourinary malignancies.

OBJECTIVE

To provide updated practical recommendations for the diagnosis and management of PUC.

EVIDENCE ACQUISITION

A systematic search interrogating Ovid (Medline), EMBASE, and the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews was performed.

EVIDENCE SYNTHESIS

Urothelial carcinoma of the urethra is the predominant histological type of PUC (54-65%), followed by squamous cell carcinoma (16-22%) and adenocarcinoma (10-16%). Diagnosis of PUC depends on urethrocystoscopy with biopsy and urinary cytology. Pathological staging and grading are based on the tumour, node, metastasis (TNM) classification and the 2016 World Health Organization grading systems. Local tumour extent and regional lymph nodes are assessed by magnetic resonance imaging, and the presence of distant metastases is assessed by computed tomography of the thorax/abdomen and pelvis. For all patients with localised distal tumours (≤T2N0M0), partial urethrectomy or urethra-sparing surgery is a valid treatment option, provided that negative intraoperative surgical margins can be achieved. Prostatic Ta-Tis-T1 PUC can be treated with repeat transurethral resection of the prostate and bacillus Calmette-Guérin. In prostatic or proximal ≥ T2N0 disease, neoadjuvant cisplatin-based chemotherapy should be considered prior to radical surgery. All patients with locally advanced disease (≥T3N0-2M0) should be discussed within a multidisciplinary team. In men with locally advanced squamous cell carcinoma, curative radiotherapy combined with radiosensitising chemotherapy can be offered for definitive treatment and genital preservation. In patients with local urethral recurrence, salvage surgery or radiotherapy can be offered. For patients with distant metastatic disease, systemic therapy based on tumour characteristics can be evaluated.

CONCLUSIONS

These updated European Association of Urology guidelines provide up-to-date guidance for the contemporary diagnosis and management of patients with suspected PUC.

PATIENT SUMMARY

Primary urethral carcinoma (PUC) is a very rare, but aggressive disease. These updated European Association of Urology guidelines provide evidence-based guidance for clinicians treating patients with PUC.

Competence against insufficiency: Why are men mostly safe from a rare and deadly prostate cancer?

Prostate cancer is a slow-growing disease, but not always. A highly rare and lethal form of the disease shows survival rates of less than a year. It is called squamous cell prostate carcinoma. In this issue of JEM, Hermanova et al. (https://doi.org/10.1084/jem.20191787) provide new findings in mouse demonstrating a strong genetic handle on both the reasons behind the rarity and the aggressiveness.

Post-Brachytherapy Transformation of Prostatic Adenocarcinoma to Squamous Cell Carcinoma: A Cadaver Anatomy Case Report

Prostatic squamous cell carcinoma comprises less than 1% of reported prostate cancers. This form of cancer has a poor prognosis with a low survival time following diagnosis and no definitive form of treatment. A Caucasian male cadaver presented with primary pure squamous cell carcinoma of the prostate with metastasis to the liver and local invasion of the bladder, ureter, and rectum. Post-mortem examination showed evidence of brachytherapy radiation seeds in the prostate. Histological analysis and clinical intuition suggest that these seeds were used in an attempt to treat a previous low-grade adenocarcinoma of the prostate. The lack of patient history complicates determining a definitive cause of death, but the pathological presentation strongly suggests that the cause of death was a pure squamous cell carcinoma of the prostate following brachytherapy treatment for a previous prostatic adenocarcinoma. This case report further aids in establishing the relationship between the use of brachytherapy for prostatic adenocarcinoma and the subsequent development of prostatic squamous cell carcinoma.

Transformation of a prostatic adenocarcinoma into squamous cell carcinoma after luteinizing hormone-releasing hormone (LHRH) agonist and radiotherapy treatment

Squamous cell carcinoma of the prostate is rare and represents 0.5% to 1% of prostatic carcinomas. Transformation of prostatic adenocarcinoma into squamous cell carcinoma after LH-RH agonist intake has been reported in only 8 cases in the literature. To our knowledge, our case is the second pure squamous cell carcinoma observed after hormonotherapy and radiotherapy. We reported a case of a patient with prostatic adenocarcinoma treated by radical prostatectomy followed by radiotherapy. Eleven years later, he had a vesical recurrence of prostatic adenocarcinoma. Our patient had an endoscopic resection followed by injections of Triptorelin. Six months later, he developed a local recurrence of a squamous cell carcinoma.

Transformation of adenocarcinoma of prostate to squamous cell carcinoma following hormonal treatment: A case report and review of the literature

Squamous cell carcinoma (SCC) of the prostate is a rare tumor with aggressive nature. This type of tumor has a poor response to conventional treatment and results in poor prognosis. Squamous differentiation or metaplasia may arise subsequent to endocrine or radiation treatment, but it is very rare. To date, a few cases have been reported in the literature. Due to its rarity, the radiologic findings of SCC of the prostate are not well established. We describe a case of SCC of the prostate developing in a patient with adenocarcinoma of the prostate following hormonal therapy. Furthermore, we review the imaging features of this rare disease across multiple imaging modalities.

Primary Adenocarcinoma of the Urethra: A Case Report and Review of the Literature

Primary adenocarcinoma of the urethra is rarely reported. We report a case of a 47-year-old male with symptoms of urinary obstruction started 2 years before diagnosis. Video-assisted urethrocystoscopy revealed a papillary mass almost obstructing the entire lumen with bleeding. Pathology report was consistent with primary adenocarcinoma of the urethra.

Primary squamous cell carcinoma of the prostate: a case report of a rare clinical entity

Primary squamous cell carcinoma of the prostate is a unique and rare clinicopathological entity with fewer than 100 cases reported in the literature. Because of its rarity, the optimal management is not well known. Here, we report a case of primary squamous cell carcinoma of the prostate which was treated with definitive concurrent chemo-radiotherapy with excellent outcome along with a brief review of the literature.

This is a case report about a rare form of prostate cancer called squamous cell cancer. It behaves more aggressively compared with more common types of prostate cancer. The treatment is controversial due to its rarity, but is different than that of the common variety of prostate cancer. From available limited information, it can be treated either with combined chemotherapy and radiotherapy or radical surgery for early stage disease.

Squamous cell carcinoma of the prostate following treatment with an LHRH-agonist: a rare case of transformation of adenocarcinoma of the prostate

Squamous cell carcinoma (SCC) is a rare variant of prostate cancer. We report a case of a patient who was diagnosed with metastatic adenocarcinoma of the prostate, treated with leuprorelin and subsequently found to have SCC 18 months later. We have found one case in the literature with a similar scenario of possible transformation of adenocarcinoma to SCC secondary to luteinizing hormone-releasing hormone (LHRH) treatment. We found interesting similarities between the two cases, which raise the possibility of the transformation of tumour type and highlights the importance of the clinical picture in the follow-up, even with low prostate specific antigen (PSA) value.

An extraordinary T/NK lymphoma, nasal type, occurring primarily in the prostate gland with unusual CD30 positivity: case report and review of the literature

Extranodal NK/T cell lymphoma(NKTCL), nasal type, occurring primarily in the prostate gland, is extremely rare. We present a case of primarily prostatic NKTCL in a 59-year-old man suffering from dysuria. Histological examinations revealed that diffused, large-sized, pleomorphic lymphocytes were arranged in an angiocentric distribution with large areas of geographic necroses. Additionally, the prostatic glands were diffusely infiltrated by heteromorphous lymphocytes forming lymphoepithelial lesions. The tumor cells were strongly expressed CD3ϵ, CD56, TIA-1, granzyme B and EBV-encoded RNAs. And interestingly, the lymphoid cells were also strongly immunoreactive with CD30. A rearrangement study showed T-cell receptor γ-chain gene rearrangement with monoclonal appearance. Though postoperative combination of chemotherapy was given, the patient died four months later. Our observation and other literatures indicate that extremely rare NKTCLs unusually express CD30. TCR gene rearrangement existed in some NKTCL, suggesting that a subset of NKTCL may be a mixed NK/T-cell differentiation.

EAU guidelines on primary urethral carcinoma

CONTEXT

The European Association of Urology (EAU) Guidelines Group on Muscle-Invasive and Metastatic Bladder Cancer prepared these guidelines to deliver current evidence-based information on the diagnosis and treatment of patients with primary urethral carcinoma (UC).

OBJECTIVE

To review the current literature on the diagnosis and treatment of patients with primary UC and assess its level of scientific evidence.

EVIDENCE ACQUISITION

A systematic literature search was performed to identify studies reporting urethral malignancies. Medline was searched using the controlled vocabulary of the Medical Subject Headings database, along with a free-text protocol.

EVIDENCE SYNTHESIS

Primary UC is considered a rare cancer, accounting for <1% of all malignancies. Risk factors for survival include age, tumour stage and grade, nodal stage, presence of distant metastasis, histologic type, tumour size, tumour location, and modality of treatment. Pelvic magnetic resonance imaging is the preferred method to assess the local extent of urethral tumour; computed tomography of the thorax and abdomen should be used to assess distant metastasis. In localised anterior UC, urethra-sparing surgery is an alternative to primary urethrectomy in both sexes, provided negative surgical margins can be achieved. Patients with locally advanced UC should be discussed by a multidisciplinary team of urologists, radiation oncologists, and oncologists. Patients with noninvasive UC or carcinoma in situ of the prostatic urethra and prostatic ducts can be treated with a urethra-sparing approach with transurethral resection and bacillus Calmette-Guérin (BCG). Cystoprostatectomy with extended pelvic lymphadenectomy should be reserved for patients not responding to BCG or as a primary treatment option in patients with extensive ductal or stromal involvement.

CONCLUSIONS

The 2013 guidelines document on primary UC is the first publication on this topic by the EAU. It aims to increase awareness in the urologic community and provide scientific transparency to improve outcomes of this rare urogenital malignancy.

Prostatic stromal sarcoma with neuroectodermal differentiation

Abstract

Prostatic stromal sarcoma is a fairly rare tumor that constitutes approximately 0.1–0.2% of all prostatic cancers. Detailed characteristics of the tumor are still unclear due to its rarity.

We describe a case of prostatic stromal sarcoma in a 63 year-old man who suffered from urinary obstructive symptoms. Palliative transuterine resection was performed and the preliminary histopathological diagnosis was neuroendocrine carcinoma. After chemotherapy, total pelvic exenteration was performed. Histopathologically, the tumor was composed of monotonously proliferating small to medium-sized round cells, which existed in compact islands with loose or dense fibrovascular networks. Immunohistochemically, the tumor cells were widely positive for vimentin, CD56, CD99 and focally positive for synaptophysin, CD10, progesterone receptor, desmin and CD34, but negative for EMA, cytokeratin, estrogen receptor, S-100 and myoglobin. Most of the previously reported tumors exhibited positive stainability for CD10 and progesterone receptor. In addition to these markers, expressions of CD56, CD99 and synaptophysin were characteristically detected in our case. To the best of our knowledge, we present the first case of prostatic stromal sarcoma with characteristic immunohistochemical staining properties. Although the biological characteristics of this rare tumor have not yet been elucidated, these findings suggest prostatic stromal sarcoma can potentially show neuroectodermal differentiation.

Virtual slide

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7291874028051262