Carcinosarcoma of the prostate. Report of 21 cases

Carcinosarcoma of the Prostate Masquerading as Benign Prostatic Enlargement: Lesson Learned

Primary carcinosarcoma of the prostate is an extremely rare and aggressive malignancy. We report a patient who presented with obstructive symptoms and without a history of radiation, prior adenocarcinoma, or androgen deprivation therapy. Transurethral resection of the prostate was performed. Histopathology and immunohistochemistry revealed a confirmatory diagnosis of de novo carcinosarcoma of the prostate. The case is described for its rarity and masquerading nature.

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.

An aortic body carcinoma with sarcomatoid morphology and chondroid metaplasia in a French Bulldog

An 11-year-old female French Bulldog was presented with a mass at the base of the heart, detected by X-ray and echocardiography. Clinical abnormality included abdominal retention by ascites. Radiation therapy was performed for 5 weeks. The mass volume didn’t change during the radiotherapy. The condition became worse and the dog died 6 months after the initial presentation and necropsy was performed. Grossly, the mass, 12.5 × 6.5 × 6.0 cm in size, was found at the base of the heart. Histopathological examination revealed that cardiac mass was composed of alveolar, bundle and diffuse proliferation of neoplastic cells. Most of the neoplastic cells showed a spindle morphology; in some areas small round or polyhedral neoplastic cells were observed. Occasional cartilage metaplasia was seen multifocal in the mass, and it was surrounded by the sarcomatoid proliferation. Electron microscopy revealed a few neuroendocrine granules in the cytoplasm of spindle and polyhedral neoplastic cells. Metastatic cells in the lungs which had not irradiated demonstrated typical morphology of aortic body tumors. Based on these findings, the case was diagnosed as an aortic body carcinoma with sarcomatoid morphology and chondroid metaplasia.

Carcinosarcoma prostate with osteosarcomatous differentiation: a rare de novo presentation

Carcinosarcoma is a rare histological event in the history of prostatic malignancies. Historically aggressive tumours with dismal outcomes reported in scarce literature available so far. Very few recent studies suggest good outcomes with modern era surgery and radiotherapy techniques in localised disease. The case presented here had no history of known risk factors like prior adenocarcinoma or prior radiation therapy. This case presented with obstructive urinary symptoms with no prostate-specific antigen elevation, diagnosed with imaging, managed aggressively with robotic surgery. Detailed immunohistochemistry and pathological review suggested diagnosis as carcinosarcoma with osteosarcomatous differentiation. Very rare such cases were reported in the past with complete clinical, radiological, pathological details and managed aggressively with good outcomes. The patient is disease free after 6 months of follow-up.

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.

Rare Pelvic Malignant Tumors in Adults: Treatment Features and Clinical Outcome in Nonmetastatic Disease (Single Institution Experience)

BACKGROUND

Nearly 200 cancers repertories are rare, and more than 20% are pelvic neoplasia. Diagnosis and treatment are challenging, even in reference centers, and survival is influenced by the aggressiveness of certain histologies and absence of a standard of care.

PATIENTS AND METHODS

The authors report the results of a retrospective analysis of patients that attended the Institute of Oncology, Bucharest, between 2004 and 2015, for nonmetastatic pelvic malignant tumor treatment and follow-up. The outcomes are compared between the rare and common histology groups.

RESULTS

Of the 60 cases analyzed, 17 patients (28.33%) bore a rare tumor, 33 (55%) were women, and the median age was 59 years. The majority was concerned by bladder (41.66%, 25 patients) and cervix (23.33%, 14 patients) neoplasms. For a median follow-up of 27.5 months, relapse was registered in 27 patients (45%), of whom 9 (33.33%) were from the rare group (53% of this subpopulation). The highest relapse rates were recorded in patients with rare bladder tumors (66.7%, 4 patients) compared with 42.1% (8 patients) in the common group (p = 0.294) and in prostate localization (66.7%, 2 patients) compared with 16.7% (1 patient) (p = 0.134). Estimated median relapse-free survival (RFS) was 60, 12 months in the rare group and 67 months for common tumors.

CONCLUSIONS

In nonmetastatic rare pelvic tumor patients, the outcome was found to be poorer than in those concerned by common histologies stratified by organ. A higher rate of relapse and the lowest median RFS were observed in bladder and prostatic cancers.

Carcinosarcoma of the prostate: case report with molecular and histological characterization

Background:

We report a case of prostatic carcinosarcoma, a rare variant of prostatic cancer, which is composed of a mixture of epithelial and mesenchymal components with a generally poor outcome.

Aims and methods:

We aim to identify molecular alterations, in particular copy number variations of AR and c -MYC genes, methylation and expression of glutathione S-transferase P1 (GSTP1), programmed death-ligand 1 (PD-L1), AR, and phosphorylated AR expression.

Results:

We found a distinct molecular pattern between adenocarcinoma and carcinosarcoma, which was characterized by high AR copy number variation gain; positive expression of PD-L1, AR, and phosphorylated AR; low espression of GSTP1 in epithelial component. The sarcomatoid component had a lower gain of the AR gene, and no expression of PD-L1, AR, phosphorylated AR, or GSTP1. Both components had a gain of c-MYC copy number variation.

Conclusions:

Our findings suggest that carcinosarcoma has specific molecular characteristics that could be indicative for early diagnosis and treatment selection.

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.

Beyond Prostate Adenocarcinoma: Expanding the Differential Diagnosis in Prostate Pathologic Conditions

Recent advances in magnetic resonance (MR) imaging of the prostate gland have dramatically improved the ability to detect and stage adenocarcinoma of the prostate, one of the most frequently diagnosed cancers in men and one of the most frequently diagnosed pathologic conditions of the prostate gland. A wide variety of nonadenocarcinoma diseases can also be seen with MR imaging, ranging from benign to malignant diseases, as well as infectious and inflammatory manifestations. Many of these diseases have distinctive imaging features that allow differentiation from prostate acinar adenocarcinoma. Early recognition of these entities produces a more accurate differential diagnosis and may enable more expeditious clinical workup. Benign neoplasms of the prostate include plexiform neurofibroma and cystadenoma, both of which demonstrate distinctive imaging features. Stromal neoplasms of uncertain malignant potential are rare tumors of uncertain malignant potential that are often difficult to distinguish at imaging from more-malignant prostate sarcomas. Other malignant neoplasms of the prostate include urothelial carcinoma, primary prostatic carcinoid, carcinosarcoma, endometrioid or ductal adenocarcinoma, and mucinous adenocarcinoma. Prostatic infections can lead to abscesses of pyogenic, tuberculous, or fungal origins. Finally, miscellaneous idiopathic disorders of the prostate include amyloidosis, exophytic benign prostatic hyperplasia, and various congenital cysts. Considerable overlap can exist in the clinical history and imaging findings associated with these prostate pathologic conditions, and biopsy is often required for ultimate confirmation of the diagnosis. However, many diagnoses, including cystadenoma, mucinous adenocarcinoma, sarcoma, and abscesses, have distinct imaging features, which can enable the informed radiologist to identify the diagnosis and recommend appropriate clinical workup and management. (©)RSNA, 2016.

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.

Contrast-enhanced ultrasound aids in the detection of prostate rhabdomyosarcoma: A case report and literature review

Prostate sarcoma is a rare malignancy with an extremely poor prognosis. The extremely low morbidity and atypical clinical symptoms contribute to a missed diagnosis. The typical features of prostate sarcoma in transrectal ultrasound (US) and magnetic resonance imaging, such as a markedly enlarged volume and irregular prostatic contours, cannot usually be found until dysuria or even uroschesis occurs, and may then be too late to treat. However, there appears to no specific tumor marker for the disease in the serum. The present study reports a case of a young male patient who was diagnosed with prostate rhabdomyosarcoma. This was, to the best of our knowledge, the first case of this diagnosis using contrast-enhanced US (CEUS) when the symptoms were not severe. In this case, the intralesional non-enhancement areas and rim-like hyper-enhancement around the lesion were considered to be the main CEUS features of prostate rhabdomyosarcoma. The present study also reviews the associated literature.

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.

Sarcomatous Carcinoma of the Orbit: A Case Report and Review of the Literature

Sarcomatous carcinomas (SCs) are rare tumours that contain malignant cells with epithelial and mesenchymal characteristics. SC rarely presents in the head and neck, and occurs even less often in the orbit. Only 8 cases of SCs located in the orbit or affecting the globe function have been described in the English literature. Here, we report a case of SC affecting the right orbit. SC is associated with a poor prognosis and advanced disease at presentation. Diagnosis is difficult, as histology often fails to definitively identify SC, necessitating a wide panel of molecular/immunological markers. Treatment options are generally aggressive but risky, and frequently yield poor results. Due to the rarity of SC, there has been little focus on the development of improved treatment options.

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.

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.

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.

Variants and unusual patterns of prostate cancer: clinicopathologic and differential diagnostic considerations

Beyond the typical acinar morphology observed in the majority of prostatic adenocarcinomas, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be classified as: (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features and/or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details a number of variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Spindle-cell carcinoma of the prostate

Sarcoma of the prostate and sarcomatoid carcinoma of the prostate are rare conditions, both characterized by a poor prognosis. Sarcomatoid carcinoma of the prostate typically arises from the evolution of an underlying adenocarcinoma, occasionally featuring heterologous elements, bulky disease being possible but rare. In contrast, sarcoma of the prostate derives from non-epithelial mesenchymal components of the prostatic stroma, shows rapid growth, and frequently presents as massive pelvic tumors obstructing the urinary tract at the time of diagnosis. We report the case of a 55-year-old patient with a two-month history of symptoms of urinary obstruction. The patient presented with an extremely enlarged heterogeneous prostate, although his prostate-specific antigen level was low. The lack of a history of prostatic neoplasia led us to suspect sarcoma, and a transrectal prostate biopsy was carried out. An immunohistochemical study of the biopsy specimen did not confirm the clinical suspicion. However, in view of the clinical features, we believe that sarcoma of the prostate was the most likely diagnosis. The patient received neoadjuvant chemotherapy followed by radiation therapy. At this writing, surgical resection had yet to be scheduled.

Sarcomatoid carcinoma of the prostate: ductal adenocarcinoma and stromal sarcoma-like appearance: a rare association

Sarcomatoid carcinoma (SC) of prostate gland is a rare biphasic tumour. In about half of cases, initial diagnosis is acinar adenocarcinoma, followed by nonsurgical therapy, with a subsequent diagnosis of SC. The survival rate is lower. We report a case of an 59-years-old man with unusual histopathologic finding of prostate sarcomatoid carcinoma, showing characteristics of ductal prostatic adenocarcinoma and prostatic stromal sarcoma-like appearance. Ductal adenocarcinoma was characterized by tall columnar cells with abundant amphophilic to eosinophil cytoplasm. Pleomorphic sarcoma was characterized to have overall glandular growth pattern, simulating a malignant phyllodes tumour. Estrogen and progesterone receptors showed nuclear immunostaining in mesenchymal multinucleated giant cells. In conclusion, SC of the prostate is an exceedingly rare tumour. Retrospective analyses render prostate SC as one of the most aggressive prostate malignancies. The prognosis is dismal regardless of other histologic or clinical findings.

[Appearance of carcinosarcoma after radiotherapy for local recurrence after radical prostatectomy. Case report and review of the literature]

Carcinosarcoma of the prostate is an extremely rare tumor. In the case of rapid tumor progression, especially after radiation therapy to the pelvis or after hormone deprivation therapy because of prostate cancer, this tumor entity should be considered, and immediate histological confirmation is required. The only curative therapy is immediate radical surgical excision. We report about the first case of a carcinosarcoma after salvage radiation therapy for local recurrence of adenocarcinoma of the prostate years after radical prostatectomy.

Carcinosarcoma of the prostate replacing the entire lower genitourinary tract

Less than 100 cases of prostate carcinosarcoma have been described in published studies. Most of these cases describe symptoms due to bladder outlet obstruction that typically results in transurethral resection of the prostate. Our patient presented with tenesmus and stranguria due to prostate carcinosarcoma that developed years after being treated with external radiation and androgen deprivation for prostate adenocarcinoma. Because of the patient's escalating symptoms, a pelvic exenteration with creation of urinary and fecal diversions was performed. Despite the dismal survival associated with prostate carcinosarcoma, palliative surgical extirpation can be successful in patients with debilitating pain.

Sarcoma of the prostate: a single institutional review

OBJECTIVE

We report the management and outcome of prostate sarcoma at 1 institution and analyze factors that may determine prognosis.

MATERIALS AND METHODS

The medical records of 10 patients with prostate sarcoma were reviewed to identify symptoms at presentation, diagnostic procedures, and staging methods. Histology, grade, tumor size, stage, and treatment modality were analyzed. Overall survival was assessed.

RESULTS

Five patients had rhabdomyosarcoma (RMS) and five had other subtypes, including two with carcinosarcoma, two with high-grade sarcoma not-otherwise-specified, and one with leiyomyosarcoma. Eight patients presented with locally advanced disease and two with metastatic disease.The two metastatic patients received chemotherapy, and one also had hormonal ablation therapy. Of the eight with local disease, two had neoadjuvant chemotherapy and surgery, one had surgery alone, one had surgery and postoperative radiation, one had radiation alone, and three had chemoradiation.Chemotherapy consisted of vincristine, adriamycin, and cyclophosphomide for rhabdomyosarcoma and of cisplatin, adriamycin, and ifosphamide for the other subtypes. Radiation dose ranged from 40 Gy to 55.8 Gy.The median survival follow-up of the study is 46.5 months. The median survival for the rhabdomyosarcoma subgroup and nonrhabdomyosarcoma subroup is 142 months and 24 months, respectively. There were three deaths, of which two had metastatic disease at presentation and one later developed distant metastases after having surgery alone. One patient developed a local recurrence 47 months after chemoradiation and was successfully salvaged with surgery.

CONCLUSIONS

In terms of tumor-related factors, the histologic subtype of prostate sarcoma appears to have prognostic significance. The overall survival for adults with non-RMS histologies is poor with a median survival of only 2 years. Pediatric patients with RMS faired much better with a median survival of over 10 years. We did not find any difference in outcome with regard to grade or tumor size. The presence of metastatic disease at diagnosis, however, is a poor predictor of outcome.In terms of treatment-related factors, surgery alone is inadequate treatment. One patient treated with surgery alone developed distant metastases 38 months later, then received chemotherapy and hormonal therapy, and died at 58 months. Patients who received combined modality treatment appear to fare better.Finally, these patients need long term follow-up. One patient developed a local recurrence 47 months after chemoradiation. This patient was successfully salvaged with surgery and is currently alive at 170 months.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Leiomyosarcoma of the prostate: case report and review of 54 previously published cases

Prostate leiomyosarcoma is an extremely rare and highly aggressive neoplasm that accounts for less than 0.1% of primary prostate malignancies. We present a patient with primary leiomyosarcoma of the prostate and review 54 cases reported in the literature to discuss the clinical, diagnostic and therapeutic aspects of this uncommon tumor. Median survival was estimated at 17 months (95% C.I. 20.7–43.7 months) and the 1-, 3-, and 5-year actuarial survival rates were 68%, 34%, and 26%, respectively. The only factors predictive of long-term survival were negative surgical margins and absence of metastatic disease at presentation. A multidisciplinary approach is necessary for appropriate management of this dire entity.

Nonepithelial Tumors and Tumor-Like Lesions of the Prostate Gland

Many significant benign and malignant nonepithelial tumors and stromal tumor-like lesions arise in the prostate gland. Although such lesions are rare, their recognition by the pathologist is essential because their treatment and prognosis are quite variable. In this review, lesions of the specialized prostatic stroma, that is, lesions that can be seen in the stroma of the prostate but not in that of other organs, except for the phyllodes type of lesions, are discussed. Benign and malignant lesions of the soft tissues that occur in the stroma of other organs and are seen with some frequency in the prostate are also discussed. Few of the rarer soft tissue lesions are mentioned. Lesions and tumors with melanocytic differentiation, hematopoietic derivation, and germ cell tumors are described. It is hoped that this review will serve as a useful reference when encountering some of these lesions, all of which are referenced to their original and subsequent reports. Some non-English language references are also cited to reflect the international recognition of these lesions or to give credit to the author who first described the entity.

Rare and unusual histological variants of prostatic carcinoma: clinical significance

We review the clinicopathological features of the following unusual histological variants of prostatic carcinoma: small cell carcinoma, ductal adenocarcinoma, sarcomatoid (carcinosarcoma), basal cell, squamous cell and adenosquamous, and urothelial carcinoma. These variants are rare and account for 5-10% of carcinomas that originate in the prostate. Some develop from acinar adenocarcinoma after hormonal or radiation therapy. They are usually aggressive tumours that often present with secondary deposits. The outcome is generally poor. Only basal cell carcinoma is seen as a low-grade carcinoma.

Sarcomatoid carcinoma after radiation treatment of prostatic adenocarcinoma

We report 2 patients with conventional prostatic adenocarcinoma who developed sarcomatoid carcinoma of probable prostatic origin 6 and 2.5 years after radiation treatment (seed implantation and external beam). Our cases had histologic features consistent with those cases previously reported in the literature. The tumors consisted of spindle cells with large hyperchromatic nuclei and a pattern mimicking a sarcoma. Immunohistochemical studies showed the tumors to be weakly positive for EMA, CK7, and vimentin. Ki67 staining showed positivity in more than 50% of tumor cells. The tumors also stained diffusely positive for p53 and p63. PSA and PAP were negative. Clinically, the sarcomatoid carcinomas appeared to be of prostatic origin. The pathogenesis of the tumors is still uncertain but most likely represent a radiation-induced dedifferentiation of prostatic adenocarcinoma.

Spindle cell lesions of the adult prostate

Prostatic spindle cell lesions are diagnostically challenging and encompass a broad array of benign and malignant processes. A subset of these lesions arises only within the prostate and generally represents entities that originate from the prostate epithelium or stroma, such as sclerosing adenosis, sarcomatoid carcinoma, stromal tumors of uncertain malignant potential (STUMP), and stromal sarcoma. Another subset of spindle cell tumors that involve the prostate are also found at other sites and include solitary fibrous tumor, leiomyosarcoma, and neural lesions among others. Finally, tumors may secondarily involve the prostate yet present as primary prostatic processes, as is evident with several cases of gastrointestinal stromal tumors (GIST). The utility of ancillary studies, including immunohistochemistry, is often limited and the main criteria for diagnosis are the morphologic findings by routine H&E stain. This review addresses the various entities that may present as spindle cell tumors within the adult prostate and discusses the functional aspects of the differential diagnosis of these lesions.

Sarcomatoid carcinoma of the prostate: a study of 42 cases

Sarcomatoid carcinoma of the prostate is a rare type of prostatic cancer. With the exception of 1 study, the morphologic features and patient outcomes have been reported only in relatively small case series and individual reports. We examined transurethral resection, needle biopsy, and radical prostatectomy specimens from 42 patients with sarcomatoid carcinoma of the prostate, all of which were received in consultation. Clinical information on 32 patients was obtainable. Five patients were lost to follow-up and information on the 5 remaining patients could not be obtained. Prior prostatic adenocarcinoma: The majority of patients (n=21; 66%) had a prior history of acinar adenocarcinoma of the prostate. Of the 14 men with available data, reported Gleason scores were 6 (n=7), 8 (n=4), and 10 (n=3). Of the remaining patients for whom this information was known, 11 patients presented with de novo sarcomatoid carcinoma. The time between the original diagnosis of acinar adenocarcinoma and diagnosis of sarcomatoid carcinoma ranged from 6 months to 16 years (mean 6.8 y). Concurrent adenocarcinoma: The majority of patients demonstrated a concurrent high grade acinar carcinoma of Gleason score 7 (n=3), 8 (n=9), 9 (n=10), and 10 (n=10). A subset of patients contained an admixed ductal adenocarcinoma (n=4), small cell carcinoma (n=3), squamous cell carcinoma (n=3), or other unusual pattern of prostate carcinoma (n=3). In 1 case, the diagnosis was based on immunohistochemical evidence of epithelial differentiation along with the history of prior adenocarcinoma. Morphology of the sarcomatoid component: The percentage of sarcomatoid growth ranged from 5% to 99% (mean 65%). Bizarre atypia with giant cells was present in 55% of cases. Admixed heterologous elements were identified in 10 cases (29%), including osteosarcomatous (n=7), chondrosarcomatous (n=5), and rhabdomyosarcomatous (n=2) elements. Of the 12 cases with received immunostains of the sarcomatoid component, 5/7 cases were at least focally positive for cytokeratin, 1/1 case was focally positive for Cam5.2, and 3/6 cases were focally positive for prostate acid phosphatase. The sarcomatoid component did not demonstrate immunoreactivity for prostate-specific antigen in 8 cases.

PROGNOSIS

approximately half of all patients developed metastatic disease either at time of presentation or subsequently. Of patients with meaningful follow-up, 6/7 died within 1 year of the diagnosis of sarcomatoid carcinoma; 20 were alive yet with very short follow-up (median 1 y; mean 2.3 y). Kaplan-Meier analysis revealed that the actuarial risk of death at 1 year after diagnosis of sarcomatoid carcinoma was 20%. No correlation was identified between patient survival and morphologic features, before radiation or hormone therapy, or concurrent high-grade prostate cancer. Sarcomatoid carcinoma demonstrates diverse spindle and epithelial cell morphologies. The sarcomatoid component often has heterologous elements and, in 1 case, no epithelial component was seen on hematoxylin and eosin-stained sections. The epithelial component is typically high-grade acinar adenocarcinoma, yet other aggressive tumor subtypes such as ductal adenocarcinoma and small cell carcinoma may also be seen. Sarcomatoid carcinoma is an aggressive form of prostate cancer, the prognosis of which is dismal regardless of other histologic or clinical findings.

Prostatic carcinosarcoma 15 years after combined external beam radiation and brachytherapy for prostatic adenocarcinoma: a case report

A 65-year-old man with a history of combined pelvic external beam radiation therapy (EBRT) and brachytherapy for prostatic adenocarcinoma 15 years prior underwent total pelvic exenteration for presumed rectal sarcoma with prostatic invasion. Pathology revealed carcinosarcoma of prostatic origin. This patient exhibited the longest reported interval between initial presentation with prostatic adenocarcinoma and development of carcinosarcoma. This case is also the first reported case of prostatic carcinosarcoma occurring after combined EBRT and brachytherapy. The increasing use of such combination high-dose radiation therapy may potentially lead to an increased incidence of secondary malignancies such as prostatic carcinosarcoma in the future.

Carcinosarcoma of the prostate. Report of a case with unusual histological findings

We report the case of a 66-year-old man who was diagnosed as having prostatic adenocarcinoma with widespread skeletal metastases. After treatment with a luteinizing hormone-releasing hormone analog for one year, a second biopsy revealed transformation of the tumour into a carcinosarcoma with heterogeneous and unusual findings in the carcinomatous as well as the sarcomatous component. Among others, these included a papillary growth pattern and a liposarcomatous differentiation. The patient died 5 months after the diagnosis of carcinosarcoma.

Clonality of sarcomatous and carcinomatous elements in sarcomatoid carcinoma of the prostate

Sarcomatoid carcinomas of the prostate are rare malignancies composed of carcinomatous and sarcomatous elements. Their etiology is uncertain and may represent a single malignant process or a mixture of two distinct malignancies. We report a clinical case of a patient who presented with locally advanced disease and was treated with hormonal and cytotoxic chemotherapy, but ultimately developed distant metastasis and died of the disease. A loss-of-heterozygosity analysis of the primary and metastatic tissues provided compelling evidence that the carcinomatous and sarcomatous elements are clonally related, supporting the hypothesis that a single malignant process underlies the etiology of sarcomatoid carcinoma of the prostate.

Case of uterine cervical carcinosarcoma

Carcinosarcoma (CS) is a rare neoplasm that is called a mixed epithelial and mesenchymal malignancy. CS of the uterine cervix is much less common than its counterparts in the uterine corpus. A 61-year-old, gravida 2, para 2 woman, who had undergone menopause 16 years prior to the presentation, was diagnosed with CS of the uterine cervix. A semiradical hysterectomy was carried out on the diagnosis of stage Ib1 cervical cancer. The patient underwent whole pelvic 45 Gy radiation as a postoperative additional treatment, but she died from multiple organ failure by metastasis 17 months after the operation. The tumor protruded from the cervix to the vagina and measured 4.5 x 3.0 cm. Histologically, the tumor was characterized as a squamous cell carcinoma and mesenchymal malignancy, represented by osteosarcomatous components. The stroma was largely composed of atypical spindle-shaped cells, which were immunohistochemically demonstrated to be of epithelial origin. Uterine cervical CS is one of the aggressive malignancies, and squamous cell carcinomas are common epithelial counterparts of cervical CS as well as adenocarcinomas.

Inflammatory Sarcomatoid Carcinoma: A Case Report and Discussion of a Malignant Tumor With Benign Appearance

Inflammatory sarcomatoid carcinoma is an aggressive tumor with an unusually benign appearance. We report the case of a 65-year-old man with a history of inoperable poorly differentiated carcinoma of the right lung, for which he had received chemoradiotherapy. A new solitary mass was discovered 4 years later in the left lung on surveillance computed tomography. The patient underwent thoracotomy with a wedge biopsy on which frozen section was performed. The nodule was vaguely granulomatous and associated with a mixed inflammatory infiltrate and a deceptively bland spindle cell proliferation. Results of immunoperoxidase studies, however, showed that the nodule contained neoplastic cells with an epithelial phenotype that were invading the pulmonary vessels. These are features of the rare inflammatory sarcomatoid carcinoma. In contrast to sarcomatoid carcinomas, this case highlights the deceptively benign appearance of inflammatory sarcomatoid carcinoma. This leads us to concur with the recommendation to exercise caution when attempting the diagnosis of apparently benign lesions on intraoperative frozen section in patients with high clinical suspicion of malignancy.

Carcinosarcoma of the prostate with multiple metastases: case report and review of the literature

A case of carcinosarcoma of the prostate in a previously healthy 65-year-old man is reported. The tumor was initially diagnosed as adenocarcinoma, but the prostatectomy specimen showed a 717-g prostate, with evidence of adenocarcinoma and carcinosarcoma without heterologous structures. By 3-month follow-up, local recurrence, and liver, lung, and bone metastases had developed in the patient. He died of disease 10 months postoperatively. Carcinosarcoma of the prostate is a very rare but highly aggressive cancer with limited therapeutic options that should be treated with surgery and managed symptomatically. We believe this article is the forty-second case reported in the literature.

Carcinosarcoma of the prostate: two cases with distinctive morphologic and immunohistochemical findings

Carcinosarcomas (CS) of the prostate are very uncommon neoplasms defined by the admixture of malignant epithelial and mesenchymal components. We describe here two new examples of CS in two patients aged 66 and 77 years, the first without previous history of prostate adenocarcinoma and the second with a 5-year history of acinar type prostate adenocarcinoma. The diagnosis of CS was made on the cystoprostatectomy specimen in the first case and transurethral resection in the second case. Both biphasic tumours exhibited papillary areas of ductal differentiation and conventional adenocarcinoma in the epithelial component, as well as malignant fibrous histiocytoma and angiosarcomatous areas in the first case and solid, poorly differentiated epithelial areas with neuroendocrine features in the second case. Immunohistochemistry revealed over-expression of c-erb B2 in the papillary epithelial component of both cases, whereas the solid undifferentiated epithelial areas in the second patient expressed c-kit, CD10 and synaptophysin, thus conforming a very undifferentiated cell population. The angiosarcomatous component of the first case expressed CD31 and CD10. The clinical course of the cases was divergent; the first patient is free of disease after radical surgery and adjuvant therapy and the other died 5 months after the diagnosis of CS, having already developed liver metastases.

Periurethral carcinosarcoma: a report of 2 cases with a review of the literature

Carcinosarcomas are rare, aggressive tumors that can arise in various sites of the body, especially the genitourinary system. In this system, the most common location for the tumor is the uterus in the female and the urinary bladder in the male. To our knowledge, only 2 cases with a periurethral location for this tumor have been previously described in the English literature. We describe 2 additional cases in this location, one in either sex, with a review of the relevant literature.

Phyllodes tumor of the prostate: long-term followup study of 23 cases

PURPOSE

Phyllodes tumor of the prostate is a rare neoplasm of uncertain malignant potential. We studied a large series of phyllodes tumors to define the combination of histological features that are most useful for predicting patient outcome.

MATERIALS AND METHODS

A total of 23 cases were obtained from our collective files from 1973 to 2002, and numerous clinical and pathological features were evaluated. A review of the reported cases of phyllodes tumor of the prostate was done.

RESULTS

Patient age was 25 to 86 years (mean 55) and they usually presented with urinary obstructive symptoms and hematuria. The diagnosis was made in 18 tumors by transurethral resection, in 2 by enucleation, in 1 by tumor resection and in 2 by prostatectomy. We analyzed 5 histological features, including cellularity (scale of 1 to 3), cytologic atypia (scale of 1 to 3), the number of mitotic figures per 10 high power fields, the stroma-to-epithelium ratio (low or high) and necrosis (present or absent). This combination of features revealed that 14 cases were low grade phyllodes tumor, 7 were intermediate grade and 2 were high grade with the high grade cases characterized by increased cellularity, severe cytological atypia, more than 5 mitotic figures per 10 high power fields and a high stroma-to-epithelium ratio, indicating stromal overgrowth. Immunohistochemical studies of 8 tumors revealed consistent, intense cytoplasmic immunoreactivity in stromal cells for vimentin and actin, in luminal epithelial cells for prostate specific antigen, prostatic acid phosphatase and broad-spectrum keratin AE1/AE3, and in basal cells for high molecular weight keratin 34beta-E12. Recurrence was seen in 7 of 14 low grade tumors (50%) and in 1 patient low grade sarcoma emerged with subsequent distant metastases 14 years after initial diagnosis following 5 recurrences. Recurrence was seen in 6 of 7 intermediate grade tumors and low grade sarcoma emerged with subsequent abdominal wall metastases in 1 patient 11 years after initial diagnosis following 3 recurrences. The phyllodes tumor recurred in each patient with high grade tumors with a time to first recurrence of 6 and 0.2 years, respectively. Distant metastases developed in these 2 patients.

CONCLUSIONS

Histological grading of prostatic phyllodes tumors is predictive of short-term outcome based on the combination of stromal cellularity, cytological atypia, number of mitotic figures and the stroma-to-epithelium ratio. However, these tumors usually recur after transurethral prostatic resection and they are often locally aggressive with time. The emergence of overt sarcoma and metastatic disease is more frequent than previously recognized. Complete resection at initial diagnosis appears to be indicated.

Unusual subtypes of prostate cancer

The vast majority of prostatic tumors developing in adult males are adenocarcinomas. For the most part, variations in histology have not received specific designations and, from a practical approach, have had any specific prognostic implications handled through application of the Gleason grading system. Nonetheless, some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some controversy regarding the appropriate application of the Gleason grading scheme in these tumors. In addition, there are carcinomas that are in fact not adenocarcinomas and that should be kept as distinct entities. In this paper, the histologic variants of adenocarcinoma are reviewed with emphasis on clinicopathologic features and the clinical relevance of these subtypes. Other carcinomas that occur in the prostate gland are also discussed again with a focus on the clinicopathologic characteristics.

Prostatic carcinosarcoma: a case report and review of literature

A unique case of carcinosarcoma of the prostate detected in a 71-year-old man is presented. Pelvic exenteration was performed, and the resected prostatic mass was found to consist of two histologically distinct elements; adenocarcinoma and sarcoma with focal osteosarcomatous element. The patient is still alive with neither metastasis nor recurrence. This is the 42nd case of carcinosarcoma of the prostate to be reported in the literature.