Rare and unusual histological variants of prostatic carcinoma: clinical significance

Ductal Adenocarcinoma of the Prostate with Novel Genetic Alterations Characterized by Next-Generation Sequencing

Ductal adenocarcinoma of the prostate (DAP) is an uncommon variant of prostate cancer associated with aggressive disease and poor outcome. It presents most frequently as a mixed tumor combined with acinar adenocarcinoma. Although the histopathological features of DAP are well known, its genomic characteristics are still evolving, prompting the suggestion that all DAP would benefit from molecular analysis with the purpose of improving tumor recognition, genetic classification, and, ultimately, personalized therapy. Herein, we report a case of DAP with novel genetic alterations (BCOR P1153S, ERG M219I, KDR A750E, POLE S1896P, and RAD21 T461del).

Gene fusion characterisation of rare aggressive prostate cancer variants-adenosquamous carcinoma, pleomorphic giant-cell carcinoma, and sarcomatoid carcinoma: an analysis of 19 cases

AIMS

To evaluate the molecular underpinnings of the rare aggressive prostate cancer variants adenosquamous carcinoma, pleomorphic giant-cell carcinoma, and sarcomatoid carcinoma.

METHODS AND RESULTS

We retrieved 19 tumours with one or more variant(s), and performed ERG immunohistochemistry, a next-generation sequencing assay targeting recurrent gene fusions, and fluorescence in-situ hybridisation (FISH) for ERG and BRAF. Divergent differentiation included: sarcomatoid carcinoma (n = 10), adenosquamous carcinoma (n = 7), and pleomorphic giant-cell carcinoma (n = 7). Five patients had more than one variant. Four had variants only in metastases. ERG rearrangement was detected in nine (47%, seven via sequencing, showing TMPRSS2-ERG fusions and one GRHL2-ERG fusion, and two via FISH, showing rearrangement via deletion). ERG was immunohistochemically positive in the adenocarcinoma in eight of nine (89%) patients, but was immunohistochemically positive in the variant in only five of nine patients (56%, typically decreased). One patient had a false-positive ERG immunohistochemical result in the sarcomatoid component despite a negative FISH result. Two (11%) harboured BRAF fusions (FAM131A-BRAF and SND1-BRAF).

CONCLUSIONS

ERG fusions are present in these rare prostate cancer variants with a frequency close to that in conventional prostate cancer (9/19, 47%). ERG immunohistochemistry usually detects rearrangement in the adenocarcinoma, but is less sensitive for the variant histology, with weak to negative staining. Adenosquamous and sarcomatoid variants can, particularly, occur together. Molecular assessment may be an additional tool in selected cases to confirm the prostatic origin of unusual tumours. The presence of two BRAF rearrangements suggests that this gene fusion may be enriched in this setting, as RAF kinase fusions have been previously reported in 1-2% of prostate cancers.

Prostatic ductal adenocarcinoma: An aggressive variant that is underdiagnosed and undersampled on transrectal ultrasound (TRUS)-guided needle biopsy

INTRODUCTION

We sought to determine if prostatic ductal adenocarcinoma is undersampled and/or underdiagnosed at transrectal ultrasound (TRUS)-guided biopsy.

METHODS

With institutional review board approval, we searched our pathology database between 2008 and 2014 for patients with a diagnosis of ≥10% ductal adenocarcinoma on radical prostatectomy and available TRUS-guided needle biopsy specimens. Three blinded genitourinary pathologists independently examined the biopsy slides. The presence or absence of ductal adenocarcinoma was determined. Diagnostic accuracy was calculated using consensus diagnosis as the reference standard. Inter-observer agreement was assessed using Cohen's kappa coefficient.

RESULTS

Based on consensus review, 66.7% (12/18) biopsy specimens demonstrated ductal adenocarcinoma and 33.3% (6/18) demonstrated conventional acinar prostatic adenocarcinoma. The sensitivity/specificity for each reader (R) was: 83/100% (R1), 100/83% (R2) and 58/83% (R3) and the inter-observer agreement was only fair (K=0.32). Only two of the original needle-biopsy reports correctly identified ductal adenocarcinoma (sensitivity = 17%). The main limitations of the study are the relatively small sample size and the potential for selection bias since we could only examine patients who underwent radical prostatectomy.

CONCLUSIONS

Prostatic ductal adenocarcinoma may be undersampled at TRUS-guided biopsy and in this study was under-reported in routine clinical practice. This highlights the importance of increased awareness of ductal adeoncarcinoma and the need for clear diagnostic criteria. These findings have significant clinical impact especially when determining candidacy for active surveillance protocols.

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.

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.

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

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

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.

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.

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.

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.

[Ductal Adenocarcinoma of the prostate with infiltration of the bladder. Can radical cystectomy and antiandrogen therapy cure the disease?]

Ductal adenocarcinoma of the prostate is a rare entity. The lack of correlation between the prostate-specific antigen value and the tumor stage, as well as early dissemination, are major differences from acinar cancer. Due to a lack of early symptoms, the tumor is often found in an advanced stage. Urinary obstruction and hematuria lead to clinical assessment. The characteristic tumor growth near the seminal colliculus can yield a negative digital rectal examination. Despite a lack of treatment guidelines, authors recommend an aggressive surgical concept. First approaches include radical prostatectomy, transurethral resection, and high-dose radiotherapy. Subsequent androgen deprivation is recommended. We report the case of a 64-year-old man with ductal prostate cancer who underwent radical cystectomy followed by androgen deprivation therapy. This is the first such case reported in both the German and the English literature.