Sarcomatoid carcinoma of the prostate: a study of 42 cases

Case report: Two cases of prostate adenocarcinoma progressing to rare sarcomatoid carcinoma with normal PSA levels following endocrine therapy

Background

Patients with prostate adenocarcinoma undergoing regular endocrine therapy may maintain normal PSA levels during follow-up, yet still progress to the highly malignant and rare prostatic sarcomatoid carcinoma, which is seldom reported. This article presents two case studies of prostatic sarcomatoid carcinoma. To date, only a few publications have described prostatic sarcomatoid carcinoma, and the clinical, morphological, and molecular dimensions of prostate adenocarcinoma warrant further investigation.

Case description

Patient A was admitted two years ago due to difficulty urinating, with a PSA level of 6.35 ng/ml. A prostate needle biopsy was performed, and the postoperative pathology diagnosed prostate adenocarcinoma with a Gleason score of 9 (5 + 4, grade group 5). Citing personal reasons, the patient declined a radical prostatectomy and instead received ongoing androgen deprivation therapy (ADT), comprising goserelin, abiraterone, and prednisone. During follow-up, regular PSA tests showed no abnormalities. One year ago, the patient was admitted again due to difficulty urinating and hematuria, choosing to address only the urethral obstruction. Transurethral resection of the prostate was performed, and the postoperative pathology diagnosed sarcomatoid carcinoma of the prostate. Patient B was admitted three years ago due to difficulty urinating accompanied by hematuria. A prostate MRI and a whole-body radionuclide bone scan suggested prostate cancer with bone metastasis. Prostate needle biopsy confirmed the diagnosis. The patient was then regularly treated with androgen deprivation therapy, using goserelin. Throughout the follow-up period, the PSA levels consistently remained within normal limits. One year ago, the patient was admitted due to rectal bleeding. It was speculated that the symptoms of rectal bleeding might have been caused by the prostate cancer invading the rectal wall. A prostate needle biopsy was performed, and the pathology diagnosed sarcomatoid carcinoma of the prostate.

Conclusions

This case underscores the inadequacy of relying solely on PSA levels to monitor high-grade prostate adenocarcinoma during endocrine therapy, as patients may progress to highly malignant atypical variants despite normal PSA levels. We propose that for high-grade prostate cancer patients who are unable to undergo radical prostatectomy, regular and frequent MRI screenings or repeat biopsies should be integral during endocrine therapy and follow-up. Furthermore, a detailed review of the patient's treatment history and clinical data, including immunohistochemical findings, might offer deeper clinical insights into prostatic sarcomatoid carcinoma.

Primary Paraganglioma of the Prostate: A Systematic Review of the Literature for A Rare Entity

BACKGROUND

Paragangliomas of the urinary tract are exceptionally uncommon, and sporadic case reports of primary paraganglioma of the prostate have been reported in the literature.

METHODS

Systematic research in PubMed/Medline and Scopus databases concerning primary prostatic paraganglioma was performed by two independent investigators.

RESULTS

This analysis included 25 adult males, with a mean age of 49.8 ± 22.4 years. 32% of included patients had a history of hypertension. Problems during urination (52%), blood loss (44%), either as hematuria or hemospermia, and catecholamine-related symptoms (36%) comprised the most frequently reported clinical manifestations. Digital rectal examination found a palpable nodule in 36% of patients, while prostatic specific antigen (PSA) was normal in all tested patients. Abdominal ultrasound (44%), computed tomography (44%) and magnetic resonance imaging (28%) helped to identify the primary lesion. 24-hour urine epinephrine, norepinephrine and vanillylmandelic acid (VMA) levels were elevated in 90%, 80% and 90% of included patients. Open surgical excision of the mass was performed in 40%, transurethral resection in 8%, open radical prostatectomy in 24%, transurethral resection of the prostate in 16% and robot-assisted radical prostatectomy in 4% of included patients.

CONCLUSION

Due to atypical clinical manifestation and scarcity of prostatic paraganglioma, urologists should be aware of this extremely rare entity.

Uncovering the Secrets of Prostate Cancer's Radiotherapy Resistance: Advances in Mechanism Research

Prostate cancer (PCa) is a critical global public health issue with its incidence on the rise. Radiation therapy holds a primary role in PCa treatment; however, radiation resistance has become increasingly challenging as we uncover more about PCa's pathogenesis. Our review aims to investigate the multifaceted mechanisms underlying radiation therapy resistance in PCa. Specifically, we will examine how various factors, such as cell cycle regulation, DNA damage repair, hypoxic conditions, oxidative stress, testosterone levels, epithelial-mesenchymal transition, and tumor stem cells, contribute to radiation therapy resistance. By exploring these mechanisms, we hope to offer new insights and directions towards overcoming the challenges of radiation therapy resistance in PCa. This can also provide a theoretical basis for the clinical application of novel ultra-high-dose-rate (FLASH) radiotherapy in the era of PCa.

The 2022 World Health Organization Classification of Tumors of the Urinary System and Male Genital Organs-Part B: Prostate and Urinary Tract Tumors

The 2022 World Health Organization (WHO) classification of the urinary and male genital tumors was recently published by the International Agency for Research on Cancer. This fifth edition of the WHO "Blue Book" offers a comprehensive update on the terminology, epidemiology, pathogenesis, histopathology, diagnostic molecular pathology, and prognostic and predictive progress in genitourinary tumors. In this review, the editors of the fifth series volume on urologic and male genital neoplasms present a summary of the salient changes introduced to the classification of tumors of the prostate and the urinary tract.

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.

Patient with prostatic adenocarcinoma with plasmacytoid features and an aberrant immunohistochemical phenotype diagnosed by biopsy and a mini-review of plasmacytoid features in the genitourinary system: A case report

Prostate cancer is one of the most commonly diagnosed malignancies in men. Most of these tumors are adenocarcinomas. Plasmacytoid is a rare variant of adenocarcinoma described by previous studies in the genitourinary system and is characterized by the plasmacytoid appearance of tumor cells with abundant cytoplasm and abnormally placed hyperchromatic nuclei. However, to the best of our knowledge, plasmacytoid adenocarcinoma has rarely been described in the prostate. This report describes a new case of plasmacytoid adenocarcinoma of the prostate diagnosed by biopsy and summarizes the known literature on plasmacytoid features in the genitourinary system. A 62-year-old male patient presented to the hospital with urinary retention, hematuria, weakness and weight loss. The digital rectal examination revealed an irregular enlargement. Laboratory findings showed elevated levels of prostate specific antigen (PSA; 43.6 ng/ml). Transrectal ultrasound showed invasion of the right seminal vesicle. Prostate tumor core biopsies were collected and sent for diagnosis. Histological examination revealed a high-grade prostatic adenocarcinoma Gleason score of 5+5 (total score 10). The tumor cells had a plasmacytoid appearance with abundant cytoplasm and abnormally placed hyperchromatic nuclei. The immunohistochemical phenotype was characterized by abundant positivity for cytokeratin (CK)AE1/AE3 and PSA. By contrast, tumor cells were negative for p63, CK 34BE12 and GATA binding protein 3 (urothelial markers), synaptophysin (neuroendocrine marker). Tumor cells were also negative for E-cadherin, which is particularly indicative of CDH1 alterations. To the best of our knowledge, this is the first description of a plasmacytoid adenocarcinoma of the prostate diagnosed by biopsy, showing an irregular immunophenotype that may indicate somatic CDH1 alterations. The presentation of a novel rare variant of prostatic carcinoma that differs from other neoplasms of the genitourinary system may contribute to an improved understanding of this uncommonly found histological pattern that may also be mandatory due to the clinical and prognostic implications of this diagnosis.

ARID1A deficient undifferentiated spindle cell and rhabdoid sarcoma of the prostate: report of a unique case with emphasis on diagnostic implications

Background

SWItch Sucrose Non-Fermentable (SWI/SNF) chromatin-remodeling complex functions collectively as a tumor suppressor and the inactivation of any of its constituent components is frequently associated with tumor initiation and/or progression. Most SWI/SNF deficient tumors share common rhabdoid morphology. ARID1A is the most frequently dysregulated SWI/SNF subunit in human cancer and inactivation of ARID1A is frequent across carcinomatous types while very rarely drives the tumorigenesis of sarcomas. Herein, we report a rare case of primary prostatic undifferentiated spindle cell sarcoma with focal rhabdoid morphology, harboring biallelic inactivation of ARID1A detected by next-generation sequencing with complete loss of ARID1A expression by immunohistochemistry.

Case presentation

The patient is a 58-year-old man who presented with dysuria and obstructive voiding symptoms for 3 month and was found to have a large, ill-defined, prostatic mass lesion with circumferential extension into the rectal wall on imaging studies. A needle biopsy showed a spindle cell undifferentiated sarcoma of the prostate and the patient was treated by chemotherapy of combined etoposide and cisplatin for 2 months. A subsequent imaging study showed that the tumor was significantly enlarged, and the patient underwent laparoscopically radical prostatectomy. Gross examination showed a disrupted, 10 × 7 × 5 cm, solid and cystic mass involving almost the entire prostate and sparing the seminal vesicle glands. Histologic examination showed that tumor was composed mainly of mildly atypical, oval to spindle-shaped cells, arranged in sheets and fascicles or herringbone-like patterns within a small amount of edematous to myxoid, vascularized stroma. Notably, groups of discohesive rhabdoid tumor cells with eccentric nuclei, prominent nucleoli, and abundant globular cytoplasm were observed. There were prominent mitotic figures, multifocal geographic necroses, and foci of lymphovascular invasion. Immunohistochemistry showed that the tumor cells were diffusely positive for TLE-1 and vimentin and focally positive for epithelial membrane antigen, AE1/3, Cam5.2, SATB2, and CD34 (all in less than 10% tumor cells). Next-generation sequencing showed biallelic inactivation mutation of ARID1A; the predicted inactivating effect of ARID1A deletion was confirmed by immunohistochemical staining. After the surgery, the patient received an alternative combined chemotherapy of doxorubicin and ifosfamide for 5 months. The patient died 9 months after initial presentation due to extensive abdominal metastases.

Conclusions

We report an ARID1A deficient undifferentiated spindle cell and rhabdoid sarcoma of the prostate, adding to the growing spectrum of SWI/SNF driven undifferentiated sarcoma. Rhabdoid cells can be a helpful morphological clue for promoting molecular and immunohistochemical analyses for deficiency of SWI/SNF subunits, in the diagnostic workup of undifferentiated neoplasms featuring epithelioid or rhabdoid morphology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-022-01198-4.

Sarcomatous Change of Cerebellopontine Angle Ependymoma Following Radiosurgery: A Case Report

Sarcomatous change in ependymal tumors is rare and has been poorly described. We report on a cerebellopontine angle lesion that demonstrated rapid progression two years after radiosurgery in a 73-year-old female patient. Histopathological diagnosis at clinical progression showed an ependymoma with sarcomatous change (“ependymosarcoma”) that was believed to be due to radiation. The patient underwent a complex tumor resection without complications using an exhaustive multi-modal neuromonitoring paradigm throughout the dissection and resection of the tumor. Given the limited available data on these rare tumors, we review their presentation, imaging, and histopathology in the context of the previous literature, and also discuss the management of these lesions in the cerebellopontine angle.

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.

Prostatic carcinosarcoma seven years after radical prostatectomy and hormonal therapy for prostatic adenocarcinoma: A case report

BACKGROUND

Prostatic carcinosarcoma is a very rare and highly aggressive tumor. It may occur after androgen deprivation therapy (ADT) for adenocarcinoma even after a 7-year interval.

CASE SUMMARY

A 66-year-old man presented with recurrent symptoms of gross hematuria and urinary retention. The patient had a previous history of combined radical prostatectomy and ADT for prostate cancer 7 years prior. He received total pelvic exenteration for a recurrent pelvic carcinosarcoma. Pathology and immunostaining revealed a carcinosarcoma of prostatic origin with focal spindled cells and bizarre giant cells. The patient subsequently underwent transverse colostomy for carcinosarcoma recurrence and bowel obstruction 3 mo later. Five months after the diagnosis of prostatic carcinosarcoma, the patient died of multiple organ metastases.

CONCLUSION

Prostatic carcinosarcoma after adenocarcinoma is exceedingly rare. ADT mediated transformation and dedifferentiation of the epithelial components may be the origin of this malignancy.

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.

Exploration on Gleason score variation trend of patients with prostate carcinoma from 1996 to 2019: a retrospective single center study

Background

Gleason score (GS) is one of the stronger prognostic factors and is integral to the management of prostate carcinoma. Subsequent modifications, recommended by the International Society of Urological Pathology in 2005 and 2014, enabled accurate prediction of prognosis. The present study investigated GS variation trend of patients with prostate carcinoma from 1996 to 2019 and offered an overview of GS changes with age, specimen type, histopathological type and serum prostate specific antigen (PSA).

Methods

One thousand three hundred and seventy-six patients, admitted to Peking University People's Hospital in 1996 to 2019, were divided into 1996 to 2006, 2007 to 2015 and 2016 to 2019 groups. Data, including demographic characteristics, GS, primary and secondary grade and percentage of primary and secondary grade of each group, were collected and analyzed. The population distribution and average of GS was evaluated, after segmented and stratified by age, type of specimen, histopathological type and PSA.

Results

The average of age and PSA of each cohort had no obvious change. The average of total GS fluctuated among three cohorts with statistically significant differences. The distribution of age and PSA did not differ among cohorts. The distribution of total and primary GS shifted, with more patients detected as total GS higher than 6 (86.1%), and more primary grade higher than 3 (56.7%) in 2016-2019. After segmented and stratified by age, specimen type, histological type and PSA, the population percentage of GS over 6 was significantly higher in 2016-2019 than 1996-2006 and 2007-2015 in patients aged younger than 80 years (age <60, 89.6%, age 60-69, 82.0%, age 70-79, 87.7%). Patients, aged below 80 years in 2016-2019, were detected with higher total GS.

Conclusions

In the present study, GS in patients with prostate carcinoma showed a upward trend. Primary grade, age, serum PSA and specimen type were the main reasons for GS changing while secondary grade, tissue types and diagnostic criteria influenced less.

Locally invasive, castrate-resistant prostate cancer in a Pten/Trp53 double knockout mouse model of prostate cancer monitored with non-invasive bioluminescent imaging

Here we have improved an existing mouse model of prostate cancer based on prostate-specific deletion of Pten and Trp53 by incorporating a Cre-activatable luciferase reporter. By coupling the deletion of those genes to the activation of a luciferase reporter, we were able to monitor tumor burden non-invasively over time. We show that, consistent with previous reports, deletion of both Pten and Trp53 on a C57BL/6 background accelerates tumor growth and results in both the loss of androgen receptor expression and castrate resistant tumors as compared with loss of Pten alone. Loss of Trp53 results in the development of sarcomatoid histology and the expression of markers of epithelial-to-mesenchymal transition Zeb1 and vimentin, with kinetics and penetrance dependent on whether one or both alleles of Trp53 were deleted. Homozygous deletion of Trp53 and Pten resulted in uniformly lethal disease by 25 weeks. While we were able to detect locally invasive disease in the peritoneal cavity in aggressive tumors from the double knockout mice, we were unable to detect lymphatic or hematogenous metastatic disease in lymph nodes or at distant sites.

Malignant solitary fibrous tumour of the prostate: four cases emphasising significant histological and immunophenotypical overlap with sarcomatoid carcinoma

Solitary fibrous tumour (SFT) is well-described in the urinary tract, but malignant examples are rare. We studied our experience with high grade malignant SFT of the prostate to address the degree of histological and immunophenotypical overlap with sarcomatoid carcinoma and prostatic stromal sarcoma. Four cases were identified from the surgical pathology consultation archives. All available H&E stained sections were reviewed. Immunostains for STAT6, CAM5.2, NKX3.1, PAX-8, GATA3, high molecular weight cytokeratin (34BE12), p40, and p63 were performed on available material. Each case was evaluated by three separate SFT prognostic risk models based on clinicopathological features, and for features of 'dedifferentiated SFT'. The patient's ages were 49, 55, 69, and 73 years. Three presented with symptoms of benign prostatic hyperplasia and one with haematuria. Tumour sizes were 5, 9, 13, and 13 cm. Mitotic rate ranged from 6 to 20 mitoses per 10 high power fields, and two cases showed abrupt transition from conventional SFT to areas with marked nuclear pleomorphism/anaplasia (i.e., 'de-differentiation'). Immunophenotypically, all four cases had strong and diffuse nuclear reactivity for STAT6. For other markers, three of three had both focal PR and GATA3 nuclear expression (up to 30% of cells). One case with 'dedifferentiated' features showed expression of multiple epithelial markers, including EMA (focal), high molecular weight cytokeratin (focal), p63, and p40. In summary, malignant SFT may rarely occur in the prostate and may closely mimic sarcomatoid carcinoma or prostatic stromal sarcoma, both histologically and immunophenotypically. Consideration of the diagnostic possibility of malignant SFT, recognition of unexpected GATA3 and PR expression, and utilisation of monoclonal STAT6 immunohistochemistry facilitate appropriate diagnosis at this unusual anatomical site.

Metastatic castration resistant prostate cancer with squamous cell, small cell, and sarcomatoid elements-a clinicopathologic and genomic sequencing-based discussion

Histologic variants are uncommon but well reported amongst cases of prostatic adenocarcinoma, including those in the setting of hormonal and/or chemoradiation therapy and castration resistance. However, the spectrum of morphologic phenotypes and molecular alterations present in such histologic variants are still incompletely understood. Herein, we describe a case of metastatic prostatic adenocarcinoma with hormonal and chemoradiation therapy-associated differentiation, displaying a combination of squamous cell, small cell, and sarcomatoid elements. The morphologic, immunohistochemical, and molecular observations are discussed with attention given to the gene alterations present, including in TP53, NF1, AR, PTEN, and RB1. Finally, we will compare our findings with those observed in uncommonly reported similar cases so as to detail the molecular underpinnings of such processes which may carry therapeutic implications.

Deletion of the p16INK4a tumor suppressor and expression of the androgen receptor induce sarcomatoid carcinomas with signet ring cells in the mouse prostate

The tumor suppressor p16^Ink4a, encoded by the INK4a gene, is an inhibitor of cyclin D-dependent kinases 4 and 6, CDK4 and CDK6. This inhibition prevents the phosphorylation of the retinoblastoma protein (pRb), resulting in cellular senescence through inhibition of E2F-mediated transcription of S phase genes required for cell proliferation. The p16^Ink4a plays an important role in tumor suppression, whereby its deletion, mutation, or epigenetic silencing is a frequently observed genetic alteration in prostate cancer. To assess its roles and related molecular mechanisms in prostate cancer initiation and progression, we generated a mouse model with conditional deletion of p16^Ink4a in prostatic luminal epithelium. The mice underwent oncogenic transformation and developed prostatic intraepithelial neoplasia (PIN) from eight months of age, but failed to develop prostatic tumors. Given the prevalence of aberrant androgen signaling pathways in prostate cancer initiation and progression, we then generated R26hAR^L/wt:p16^L/L: PB-Cre4 compound mice, in which conditional expression of the human AR transgene and deletion of p16^Ink4a co-occur in prostatic luminal epithelial cells. While R26hAR^L/wt:PB-Cre4 mice showed no visible pathological changes, R26hAR^L/wt:p16^L/L: PB-Cre4 compound mice displayed an early onset of high-grade PIN (HGPIN), prostatic carcinoma, and metastatic lesions. Strikingly, we observed tumors resembling human sarcomatoid carcinoma with intermixed focal regions of signet ring cell carcinoma (SRCC) in the prostates of the compound mice. Further characterization of these tumors showed they were of luminal epithelial cell origin, and featured characteristics of epithelial to mesenchymal transition (EMT) with enhanced proliferative and invasive capabilities. Our results not only implicate a biological role for AR expression and p16^Ink4a deletion in the pathogenesis of prostatic SRCC, but also provide a new and unique genetically engineered mouse (GEM) model for investigating the molecular mechanisms for SRCC development.

MicroRNAs and epithelial-mesenchymal transition in prostate cancer

Prostate cancer (PCa) is a leading cause of male cancer-related deaths. A significant fraction of prostate tumors are very aggressive, often metastasizing to bone, causing significant morbidity and mortality. Also, PCa is associated with high rates of recurrence, often attributed to the existence of cancer stem cells. Epithelial-mesenchymal transition (EMT), a process characterized by decreased expression of epithelial genes and increased expression of mesenchymal genes, plays a critical role in tumor invasion, metastasis and recurrence. In PCa, EMT has been implicated particularly in the context of metastatic disease and microRNAs have emerged as critical post-transcriptional regulators of PCa EMT. In this review, we summarize the role of miRNAs in PCa EMT that play a role in progression, metastasis and recurrence. Studies till date suggest that microRNAs mediate efficient and reversible control of PCa EMT via multiple mechanisms including either by (i) directly repressing single or multiple EMT-TFs or regulating cytoskeletal components (epithelial/mesenchymal genes) or (ii) regulating key signaling pathways involved in EMT. Oncogenic microRNAs often act as EMT promoters by repressing epithelial characteristics and tumor suppressive miRNAs act by inhibiting mesenchymal progression. Further, EMT is mechanistically linked to stem cell signatures in PCa and several miRNAs implicated in EMT have been reported to influence PCa stem cells. Loss of EMT-inhibiting miRNAs and/or gain of EMT promoting miRNAs lead to induction of PCa EMT, leading to tumor progression, metastasis and recurrence. Restoring expression of tumor suppressive miRNAs and inhibiting oncogenic miRNAs represent potential therapeutic opportunities to prevent disease metastasis and recurrence.

Mesenchymal tumors of the prostate

Mesenchymal tumors of the prostate are rare but often cause considerable diagnostic difficulty when encountered. These may be either benign or malignant and can arise within the prostate gland or in adjacent tissues. This review covers prostatic stromal proliferations (prostatic stromal tumor of uncertain malignant potential and stromal sarcoma), solitary fibrous tumor, myofibroblastic proliferations, smooth muscle neoplasms (leiomyoma and leiomyosarcoma), gastrointestinal stromal tumor, schwannoma, rhabdomyosarcoma, sarcomatoid carcinoma, postradiation sarcoma, and mixed epithelial stromal tumor of the seminal vesicle. Differential diagnostic considerations are emphasized, including descriptions of helpful histological and/or clinical clues and the use of adjuvant diagnostic techniques.

Histopathology of Prostate Cancer

This review focuses on histopathological aspects of carcinoma of the prostate. A tissue diagnosis of adenocarcinoma is often essential for establishing a diagnosis of prostate cancer, and the foundation for a tissue diagnosis is currently light microscopic examination of hematoxylin and eosin (H&E)-stained tissue sections. Markers detected by immunohistochemistry on tissue sections can support a diagnosis of adenocarcinoma that is primary in the prostate gland or metastatic. Histological variants of carcinoma of the prostate are important for diagnostic recognition of cancer or as clinicopathologic entities that have prognostic and/or therapeutic significance. Histological grading of adenocarcinoma of the prostate, including use of the 2014 International Society of Urological Pathology (ISUP) modified Gleason grades and the new grade groups, is one of the most powerful prognostic indicators for clinically localized prostate cancer, and is one of the most critical factors in determination of management of these patients.

Carcinosarcoma of the Tunica Vaginalis Following Radiation Therapy for Localized Prostate Cancer

Spermatic cord tumors (SCTs) are rare neoplasms with 80% exhibiting benign pathology. Of the malignant SCTs, 90% are sarcomas. To date there has only been one documented case of primary CS of the spermatic cord which occurred in a 40 year old with no reported medical history. A 76-year-old male with a history of biopsy proven Gleason score 7 (3 + 4) prostatic adenocarcinoma underwent external beam radiation therapy (7920 cGy) in 44 fractions in 2004. He presented with a 3 year history of an asymptomatic right hydrocele. Several scrotal ultrasounds had been performed confirming a hydrocele, with the most recent revealing a hydrocele measuring 10 × 14 cm and several epididymal cysts. During the hydrocelectomy a firm suspicious mass was noted inside the tunica vaginalis and involving the spermatic cord. Given the intraoperative findings, decision was made to proceed with radical orchiectomy. Final pathologic examination revealed the tumor to have a biphasic pattern composed of spindled cells and also cells with an epithelioid morphology. Five months following orchiectomy he patient presented with a painful, enlarging right upper scrotal mass. A CT scan revealed new soft tissue lesions suspicious for necrotic lymph nodes within the right inguinal canal. Additional metastatic evaluation revealed multiple new pleural and parenchymal lung nodules. CT guided needle biopsy of a left lung nodule demonstrated spindle cells with high cellularity and areas of necrosis which were histomorphologically similar to the previous scrotal CS. Gemcitabine therapy was subsequently started. Four months following the diagnosis of metastatic CS, the patient expired. Dedifferentiation of prostatic adenocarcinoma to prostatic CS should be considered as a treatment outcome after localized radiation therapy to the prostate due to the highly aggressive nature of metastatic CS.

A novel microRNA regulator of prostate cancer epithelial-mesenchymal transition

The most frequent alteration in the prostate oncogenome is loss of chromosome (chr) 8p21 that has been associated with loss of NKX3.1 homeobox gene. Chr8p21 deletions increase significantly with tumor grade and are associated with poor prognosis in prostate cancer (PCa), suggesting critical involvement of this region in tumor progression. Recent studies suggest that apart from NKX3.1, this region harbors alternative tumor suppressors that are yet undefined. We proposed a novel, paradigm shifting hypothesis that this locus is associated with a miRNA gene cluster-miR-3622a/b- that plays a crucial suppressive role in PCa. Here we demonstrate the crucial role of miR-3622a in prostate cancer epithelial-to-mesenchymal transition (EMT). MicroRNA expression profiling in microdissected human PCa clinical tissues showed that miR-3622a expression is widely downregulated and is significantly correlated with poor survival outcome and tumor progression. To understand the functional significance of miR-3622a, knockdown and overexpression was performed using non-transformed prostate epithelial and PCa cell lines, respectively, followed by functional assays. Our data demonstrate that endogenous miR-3622a expression is vital to maintain the epithelial state of normal and untransformed prostate cells. miR-3622a expression inhibits EMT, progression and metastasis of PCa in vitro and in vivo. Further, we found that miR-3622a directly targets EMT effectors ZEB1 and SNAI2. In view of these data, we propose that frequent loss of miR-3622a at chr8p21 region leads to induction of EMT states that in turn, promotes PCa progression and metastasis. This study has potentially significant implications in the field of prostate cancer as it identifies an important miRNA component of a frequently lost chromosomal region with critical roles in prostate carcinogenesis which is a highly significant step towards understanding the mechanistic involvement of this locus. Also, our study indicates that miR-3622a is a novel PCa biomarker and potential drug target for developing therapeutic regimens against advanced PCa.

Surgical Management of Primary Spindle Cell Sarcoma of Prostate

Primary spindle cell sarcoma of prostate is an extremely rare malignancy and very few cases of it have been reported Ozturk and Sivrikoz, 2013; Hansel and Epstein, 2006. We searched the literature through MEDLINE database using PubMed and Scopus for the articles published between January 1988 and September 2016. Our search was limited to the following keywords: "spindle cell sarcoma," "prostate," and "surgical management." Most of the papers focused on histopathology of the tumor, and very few discussed surgical management. We present a case of localized primary spindle cell sarcoma of the prostate operated at our institute with the difficulties we faced and their management.

[Primary prostatic sarcoma - a rare malignancy]

Primary prostatic sarcomas are rare, reportedly comprising less than 1% of all prostate malignancies. Most patients present with lower urinary tract symptoms due to bladder outlet obstruction. Prostate-specific antigen (PSA) is typically normal. Histological confirmation and staging by a computed tomography (CT) or magnetic resonance imaging (MRI) scan of the pelvis and abdomen are essential for diagnosis and treatment planning. The differential diagnosis includes sarcomatoid prostate cancer or benign spindle cell tumors. Primary prostatic sarcomas are often aggressive and require multimodal treatment with surgery and (neo)adjuvant radiation and/or chemotherapy. The risk of local recurrence is high and the long-term prognosis is poor.

Optimal management of prostate cancer with lethal biology--state-of-the-art local therapy

Defining prostate cancer with lethal biology based upon clinical criteria is challenging. Locally advanced/High-Grade prostate cancer can be downstaged or even downgraded with cure in up to 60% of patients with primary therapy.12345 However, what is known is that high-grade prostate cancers have a greater potential for recurrence and progression to metastatic disease, which can ultimately result in a patient's death. Patients with clinical features of “high-risk” prostate cancer (cT2c, PSA >20, ≥ Gl 8 on biopsy) are more likely to harbor more aggressive pathologic findings. The optimal management of high-risk prostate cancer is not known as there are not prospective studies comparing surgery to radiation therapy (RT). Retrospective and population-based studies are subject to many biases and attempts to compare surgery and radiation have demonstrated mixed results. Some show equivalent survival outcomes6 while others showing an advantage of surgery over RT.7891011 Local therapy for high-risk disease does appear to be beneficial. Improved outcomes realized with local therapy have been clearly demonstrated by several prospective studies evaluating androgen deprivation therapy (ADT) alone versus ADT plus RT. The combination of local with systemic treatment showed improved disease-specific and overall survival outcomes.121314 Unfortunately, primary ADT for N0M0 prostate cancer is still inappropriately applied in general practice.11 While the surgical literature is largely retrospective, it too demonstrates that surgery in the setting of high-risk prostate cancer is effective in providing durable disease-specific and overall survivals.2315

The pathology of unusual subtypes of prostate cancer

There are some current literatures describing the morphologic change of prostate carcinoma variants. Some subtypes do not respond to hormone deprivation therapy, for example adenosquamous and squamous cell carcinoma (SQCC), basaloid and adenoid cystic carcinoma (ACC), small cell carcinoma (SmCC), sarcomatoid carcinoma, urothelial carcinoma; some are defined in special Gleason grade, some develop different prognosis. So, it is very important to identify these rare subtypes to avoid misdiagnosis. In this review, we aim to describe the typical clinicopathological features of the rare variants of prostate cancer, including prostate acinar adenocarcinoma morphologic variants.

Sarcomatoid Urothelial Carcinoma of the Bladder: Analysis of 28 Cases With Emphasis on Clinicopathologic Features and Markers of Epithelial-to-Mesenchymal Transition

Context.—Sarcomatoid urothelial carcinoma (UCa) is a rare but aggressive variant of bladder cancer that can show diagnostic challenges even using ancillary techniques.

Objective.—To examine immunohistochemical markers in the context of sarcomatoid UCa, including those associated with epithelial-to-mesenchymal transition.

Design.—Twenty-eight cases of sarcomatoid UCa were rereviewed. Clinical outcomes were obtained through database search. Immunohistochemistry for clinical and epithelial-to-mesenchymal transition markers was performed.

Results.—All patients had biopsy-proven invasive UCa; 61% (17 of 28) had sarcomatoid UCa at initial diagnosis. A recognizable epithelial component(s) was present in 17 lesions. The sarcomatoid component accounted for 65% of the lesion (average), with heterologous elements present in 3 of 28 cases (11%). The morphologic spectrum of the sarcomatoid element included spindled not otherwise specified, myxoid, pseudoangiosarcomatous, and malignant fibrous histiocytoma–like undifferentiated features. The sarcomatoid component was immunoreactive for pancytokeratin (22 of 26; 85%), p63 (20 of 26; 77%), cytokeratin 903 (17 of 26; 65%), cytokeratin 7 (16 of 26; 62%), GATA3 (16 of 26; 62%), and cytokeratin 5/6 (16 of 26; 62%). STAT-6, CD31, CD34, and HMB45 were all nonreactive, whereas smooth muscle actin often showed at least focal immunoreactivity (22 of 26; 85%). Epithelial-to-mesenchymal transition markers were frequently expressed, including vimentin (26 of 26; 100%), FoxC2 (26 of 26; 100%), SNAIL (23 of 26; 88.5%), and ZEB1 (18 of 26; 69.2%). Follow-up was available for 24 patients (median, 7 months). Sixteen of 28 patients (57%) died of disease (overall mean survival, 9.1 months). The presence of myxoid or chordoid features was associated with reduced survival (P &lt; .05).

Conclusions.—Sarcomatoid UCa is an aggressive form of UCa that frequently expresses epithelial-to-mesenchymal transition markers, suggesting a possible mechanism associated with aggressive tumor behavior.

A CASE OF A CARCINOSARCOMA OF THE PROSTATE

Carcinosarcoma of the prostate is a rare but aggressive tumor characterized by combination of malignant epithelial and mesenchymal cells. We encountered a case of carcinosarcoma of the prostate. A 78-year-old man with urinary retention was diagnosed with benign prostatic hyperplasia on the basis of the ultrasonography and rectal examination findings, negative result of prostate biopsy. Transurethral resection of the prostate was performed, and the pathological diagnosis was carcinosarcoma of the prostate with squamous cell carcinoma. The patient died of disease 5 months after the diagnosis of carcinosarcoma. A total of 17 cases of carcinosarcoma of the prostate including the present case, have been reported in the Japanese literature to date. Herein we review the 17 cases and discuss the clinical features.

Primary sarcomatoid carcinoma of the mandibular gingiva: clinicopathological and radiological findings

Sarcomatoid carcinoma is a rare, malignant biphasic neoplasm with an epithelial and a spindle cell component. Primary sarcomatoid carcinomas arising from mandibular gingiva are known to be extremely rare, with only one case reported to date. Herein, we discuss the radiographic and computed tomographic appearances and pathological features of primary mandibular sarcomatoid carcinoma, which was confirmed by clinicopathology, in a 72-year-old man. In addition, we present a brief review of the relevant literature.

Sarcomatoid Carcinoma of the Prostate: Retrospective Review of a Case Series From the Johns Hopkins Hospital

OBJECTIVE

To identify survival differences in patients with sarcomatoid prostate cancer based on initial staging and treatment regimens.

METHODS

We retrospectively reviewed the clinical outcomes of patients with a pathologically confirmed diagnosis of sarcomatoid prostate cancer. The primary statistical objective was to estimate overall survival (OS) and to assess the survival of patients at different stages treated with local and/or systemic approaches.

RESULTS

We identified 70 transurethral resections, needle biopsies, or prostatectomy specimens that were reviewed by the Department of Pathology at the Johns Hopkins Hospital from 2002-2012 and given the diagnosis of sarcomatoid prostate cancer. Of the 45 patients with available survival data, complete medical histories were obtained for 27 patients who were stratified based on a modified staging system (local disease, local disease with bladder invasion, and metastatic disease). After a median follow-up of 106 months, the median OS of patients in the local disease group was not reached. Notably, 5 of the 9 patients diagnosed with local disease survived >5 years and were treated with surgery and/or external beam radiation therapy. The OS hazard was significantly increased in patients with either clinical evidence of bladder invasion (HR: 20.46 [95% CI: 2.43,172]; P = 0.005) or metastatic disease (HR: 43.34 [95% CI: 4.39,427.4]; P = 0.001), which both demonstrated poor outcomes (median OS: local disease with bladder invasion-9 months; metastatic disease-7.1 months).

CONCLUSION

This retrospective analysis suggests that local sarcomatoid prostate cancer can be effectively treated with definitive therapy leading to favorable outcomes.

Mouse models of prostate cancer: picking the best model for the question

When the National Institutes of Health Mouse Models of Human Cancer Consortium initiated the Prostate Steering Committee 15 years ago, there were no genetically engineered mouse (GEM) models of prostate cancer (PCa). Today, a PubMed search for "prostate cancer mouse model" yields 3,200 publications and this list continues to grow. The first generation of GEM utilized the newly discovered and characterized probasin promoter driving viral oncogenes such as Simian virus 40 large T antigen to yield the LADY and TRAMP models. As the PCa research field has matured, the second generation of models has incorporated the single and multiple molecular changes observed in human disease, such as loss of PTEN and overexpression of Myc. Application of these models has revealed that mice are particularly resistant to developing invasive PCa, and once they achieve invasive disease, the PCa rarely resembles human disease. Nevertheless, these models and their application have provided vital information on human PCa progression. The aim of this review is to provide a brief primer on mouse and human prostate histology and pathology, provide descriptions of mouse models, as well as attempt to answer the age old question: Which GEM model of PCa is the best for my research question?

Primary spindle cell sarcoma of the prostate and (18)F-fluorodeoxyglucose-positron-emission tomography/computed tomography findings

Background:

Primary sarcoma of the prostate is extremely rare and accounts for 0.1% of all prostate cancers. This type of cancer is associated with poor prognosis due to aggressive biological behavior. The World Health Organization histologically classified prostate sarcomas as stromal tumor of unknown malignant potential (STUMP) and stromal sarcoma.

Patients and Methods:

A 39-year-old patient presented with lower urinary tract symptoms over the last few months. On digital rectal examination, the right lobe of the prostate was diffusely hard on palpation. Prostate-specific antigen was 0.5 ng/ml. A biopsy specimen was obtained with the guidance of transrectal ultrasonography. Immunohistochemical examination revealed positive staining for vimentin, actin, and desmin.

Results:

¹⁸F-fluorodeoxyglucose-positron-emission tomography/computed tomography scans obtained for staging purposes with the diagnosis of primary spindle cell carcinoma of the prostate revealed widespread lung and liver metastases. A doxorubicin-based systemic chemotherapy (CTx) was initiated.

Conclusion:

Spindle sarcomas of the prostate have quite aggressive nature and they have high potential to metastase. Average life expectancy is <1 year and the prognosis is poor. CTx and radiation therapy can’t yield curative effects due to poor differentiation.

Mixed adenocarcinoma, sarcomatoid carcinoma and adenosquamous carcinoma of the prostate: A case report

Adenosquamous carcinoma (ASC) and sarcomatoid carcinoma (SC) of the prostate are rare, but highly aggressive tumors. The occurrence of mixed carcinomas in the prostate is even more rarely reported. The present study reports the case of a 62-year-old male who was diagnosed with prostatic adenocarcinoma accompanied by multiple bone metastases, as shown by a needle biopsy and skeletal computed tomography scan. The patient was treated with hormonal therapy, but thereafter, specimens from a transurethral resection of the prostate (TURP) were found to be composed of three histologically distinct elements: ASC, SC and adenocarcinoma. The level of p53 was evaluated by immunohistochemistry in detail, and it was found that this was significantly increased in the TURP samples compared with the needle biopsy samples. The abnormal level of p53 was likely associated with the prognosis of the patient; the patient succumbed to prostate carcinoma two months after the confirmation of the diagnosis.

Sarcoma-like tumor of head and neck skin

A group of tumors referred to as atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) predominantly occur in sun-damaged skin of the elderly, particularly in the head and neck region. Although this group of tumors is often regarded as of mesenchymal phenotype, the matter of histogenesis has not been entirely resolved. Evans H and Smith JL reported in 1980 that prognosis was not significantly different irrespective of whether there was a definite squamous cell carcinoma component or not, supporting a view that these are all carcinomata in nature (sarcomatoid carcinoma [SC]). There are a number of clinicopathologic studies of AFX in the literature but information on morphologically similar sarcoma-like tumors with immunohistochemical evidence of epithelial differentiation is sparse. One hundred sarcoma-like tumors (SLTs) of head and neck skin of the elderly, treated by surgical excision, were studied. Clinical information was obtained, and pathology reports and hematoxylin and eosin sections were reviewed to document size (maximum dimension), extent of invasion, mitotic count, vascular and perineural invasion, margin status, ulceration, necrosis, and the presence of actinic keratosis in adjacent/overlying skin. Immunostains examined included: pan-cytokeratins (CKs) (AE1/AE3, MNF116), high-molecular weight CKs (34βE12, CK5/6, CK14), p63, and melanocytic (S100, Melan A, HMB-45, MITF), vascular (CD31, CD34), and muscle markers (SMA, desmin, h-caldesmon) to exclude melanoma and definite sarcoma entities. The tumors were divided into AFX/PDS (G1), the SC group, which was subdivided into SLT with only p63 positivity (G2a) and SLT with CK positivity regardless of p63 status (G2b), and SLT with a minor morphologic squamous cell carcinoma component (G3). Clinicopathologic findings of each group were compared, in relation to outcomes. Age at diagnosis ranged from 51 to 96 years (median, 79 y), with M:F=11.5:1. There were 53 tumors in G1 (19AFX, 34PDS), 37 in G2 (25 in G2a, 12 in G2b), and 10 in G3. There was no statistically significant difference in clinical and pathologic parameters or survival among all 3 groups. CKs and p63 expression, size, extent of invasion, vascular invasion, perineural invasion, mitotic count, and ulcer did not affect outcome, whereas margin status and necrosis did by both univariate and multivariate analysis and by only univariate analysis, respectively. Sixty patients had multiple nonmelanomatous skin cancers. Actinic keratosis was observed in overlying/adjacent epidermis in 51 cases. Eight patients had prior radiotherapy to head skin cancers; 1 patient developed 2 separate tumors (G1 and G3) after radiotherapy. Four patients died of tumor (1 G1, 2 G2b, and 1 G3); of these, 3 cases had positive margin, and 1 had narrow margin. Our results have shown similarities of various clinicopathologic parameters between AFX/PDS and SC, raising the possibility that both entities are related, and some of the former entities may represent complete dedifferentiation (complete loss of epithelial phenotype) with a gain of mesenchymal phenotype. In addition, the difference between AFX and PDS appears to be the extent of invasiveness (stage) rather than a different histogenesis. Further investigations are needed. However, from a practical point of view, efforts should be made to excise this group of tumors with clear margins, as margin status appears to be the most important prognostic factor regardless of the presence or absence of epithelial differentiation.

Carbon ion irradiation of the human prostate cancer cell line PC3: a whole genome microarray study

Hadrontherapy is a form of external radiation therapy, which uses beams of charged particles such as carbon ions. Compared to conventional radiotherapy with photons, the main advantage of carbon ion therapy is the precise dose localization along with an increased biological effectiveness. The first results obtained from prostate cancer patients treated with carbon ion therapy showed good local tumor control and survival rates. In view of this advanced treatment modality we investigated the effects of irradiation with different beam qualities on gene expression changes in the PC3 prostate adenocarcinoma cell line. For this purpose, PC3 cells were irradiated with various doses (0.0, 0.5 and 2.0 Gy) of carbon ions (LET=33.7 keV/μm) at the beam of the Grand Accélérateur National d’Ions Lourds (Caen, France). Comparative experiments with X-rays were performed at the Belgian Nuclear Research Centre. Genome-wide gene expression was analyzed using microarrays. Our results show a downregulation in many genes involved in cell cycle and cell organization processes after 2.0 Gy irradiation. This effect was more pronounced after carbon ion irradiation compared with X-rays. Furthermore, we found a significant downregulation of many genes related to cell motility. Several of these changes were confirmed using qPCR. In addition, recurrence-free survival analysis of prostate cancer patients based on one of these motility genes (FN1) revealed that patients with low expression levels had a prolonged recurrence-free survival time, indicating that this gene may be a potential prognostic biomarker for prostate cancer. Understanding how different radiation qualities affect the cellular behavior of prostate cancer cells is important to improve the clinical outcome of cancer radiation therapy.

High-Grade Primary Spindle Cell Sarcoma of the Prostate: A Case Report and Review of the Literature

Evaluation of the primary spindle cell sarcoma prostate, which is seen extremely rare, is aimed. Literature search was made through a search in the MedLine database using PubMed and Scopus for the articles published between January 1988 and September 2013. Electronic search was limited to the following keywords: “spindle cell sarcoma”, “primary prostate sarcoma”. Primary prosatate sarcoma was reported as 100 patients in literature. High-grade primary spindle cell sarcoma of the prostate was encountered as 16 patients in literature. This patients was reported as the 17th case. It is a difficult cancer due to diagnosis and treatment because of the short average life expectancy, high potential of asymptomatic aggressive and metastatic. Histopatogenesis is not exactly known. In 50% of composed of patients who are previously diagnosed with prostate adenocarcinom. The case was reported as high-grade primary prosatate sarcoma at an early age. The case is different from other cases because of not being adenocarcinom component.

Prostatic stromal neoplasms: differential diagnosis of cystic and solid prostatic and periprostatic masses

OBJECTIVE

The objectives of this article are to illustrate the radiologic-pathologic correlation of prostate stromal neoplasms and to review the imaging appearances of cystic and solid prostatic and periprostatic masses that may mimic prostatic stromal neoplasms.

CONCLUSION

The differential diagnosis for cystic and solid masses in the prostate is broad, and masses arising from periprostatic structures may mimic the appearance of primary prostatic diseases. Attention to clinical and imaging features is helpful in narrowing the differential diagnosis.

Sarcomatoid carcinoma of the prostate

Sarcomatoid carcinoma of the prostate is among the rarest malignant neoplasm types and has been well known for its aggressive clinical course. Patient was admitted with the symptoms of lower urinary tract. Transurethral resection of prostate (TUR-P) was carried out. Revealing Gleason 5 + 3 = 8 prostate adenocarcinoma in TUR-P material. Thereby, a Radical Prostatectomy procedure was planned. In operation, frozen examination revealed adenocarcinoma metastasis to the obturator lymph node. The operation was terminated. In the postoperative 3rd month, the patient was re-admitted with acute urinary system symptoms. A cystoscopy performed and complete resection of the mass was performed. The pathological examination reported that the tumor was compatible with undifferentiated adenocarcinoma owing to presence of poorly differentiated tumoral cells and detection of adenocarcinoma in a relatively small (<1%) focus. 4 month after the operation, the patient underwent another cyctoscopic examination which revealed the prostatic lounge and most of the bladder lumen to be filled with tumoral tissue. The tumoral tissues was resected incompletely. This material was diagnosed to be "Sarcomatoid Malignant Tumor" upon the new evidences of progressive dedifferentiation and predominant sarcomatoid appearance, compared with the former TUR-P materials. Subsequent PET-CT scan depicted multiple metastasis. The patient was referred to oncology department. In conclusion, sarcomatoid carcinoma is a malignant variant that brings along diagnostic and treatment difficulties.

Spindle cell carcinoma of the larynx with rhabdomyoblastic heterologous element: a rare form of divergent differentiation

Spindle cell (sarcomatoid) carcinoma of the larynx is a rare subtype of squamous cell carcinoma that shows a prominent spindle cell component with a mesenchymal phenotype. Heterologous elements may be seen in these spindled areas and usually consist of osteosarcomatous or chondrosarcomatous differentiation. We describe an unusual spindle cell carcinoma of the vocal cord in a 68-year-old male which demonstrated rhabdomyosarcomatous differentiation as confirmed by desmin and myogenin immunoreactivity. Thus rhabdomyosarcomatous differentiation adds to the phenotypic spectrum of spindle cell carcinomas of the larynx and should be considered before invoking a diagnosis of true rhabdomyosarcoma of the larynx.