The prostatic gland: malignancies other than adenocarcinomas

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

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

Imaging of non-epithelial neoplasms of the prostate

The purpose of this article is to review the spectrum of rare non-epithelial tumors of the prostate. This focused article will help the readers to understand the imaging findings of such rare entities attributed to their clinicopathological features. Radiologists must be familiar with the spectrum of non-epithelial tumors of the prostate, which helps to suggest alternate diagnosis other than adenocarcinoma, when imaging features are atypical. This is important because these tumors have different management approaches and prognoses when compared to adenocarcinoma of the prostate.

Leiomyosarcoma of the prostate-an unexpected histopathological outcome

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

MR Imaging of the Prostate Gland

This article discusses MR imaging of the normal prostate and of disease conditions of the prostate including prostatitis, cystic lesions, amyloidosis, calculi, hematospermia, benign prostatic hyperplasia, and malignancy.

Giant prostatic hyperplasia: report of a previously asymptomatic man presenting with gross hematuria and hypovolemic shock

Giant prostatic hyperplasia is a rare condition characterized by very high volume benign prostatic enlargement (>500g). Few cases have been reported so far and most of them are associated with severe lower urinary symptoms. We report the first case of asymptomatic giant prostatic hyperplasia in an elderly man who had a 720g prostate adenoma, sudden gross hematuria and hypovolemic shock. The patient was successfully treated with open transvesical prostatectomy and had an uneventful postoperative recovery.

Malignant nonepithelial prostate tumors: FDG PET/CT findings with MRI and CT correlation

PURPOSE

The aim of this study was to evaluate F-FDG PET/CT findings of malignant nonepithelial prostate tumors and their correlation with MRI and CT images.

PATIENTS AND METHODS

FDG PET/CT findings were reviewed in 12 patients with malignant nonepithelial prostate tumor confirmed by pathology. The location, size, SUVmax, pathologic findings, and available MRI and CT images of the tumors were reviewed.

RESULTS

Of the 12 patients (mean age, 41 years; age range, 19-66 years), 9 had normal prostate-specific antigen levels. The mean size of the tumors was 7.1 cm in diameter ranging from 4.6 to 10.5 cm. All the tumors showed increased metabolic activity with mean SUVmax of 17.5 ranging from 3.6 to 46.8. The high-grade malignant tumors tended to show higher FDG uptake, whereas the intermediate-grade and low-grade malignant ones tended to show lower FDG uptake. Seven tumors had local invasion or distant metastases. Lung was the most common metastatic site. On MRI, the tumors showed well-circumscribed or ill-circumscribed margins with inhomogeneous enhancement. On CT, the tumors showed hypodensity with slight to moderate enhancement.

CONCLUSIONS

The malignant nonepithelial prostate tumors tended to have large sizes at presentation, have high FDG uptake, and affect a younger population with normal prostate-specific antigen levels. FDG PET/CT may be useful for the assessment of tumor grade and for detecting the distant metastases, whereas the MRI or enhanced CT may be more helpful for describing the relationship between the tumor and adjacent structures.

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.

Imaging appearance of sarcomas of the prostate

Sarcomas of the prostate are rare tumours. Their clinicopathologic features are well described, however, the imaging features of these tumours have rarely been documented. The purpose of this article is to illustrate the imaging findings of prostate sarcomas, with an emphasis on their appearance on magnetic resonance imaging and to identify features that may help to differentiate them from the commoner prostate adenocarcinomas.

Acute myeloid leukemia incidence following radiation therapy for localized or locally advanced prostate adenocarcinoma

INTRODUCTION

The effect of radiation therapy on acute myeloid leukemia incidence among prostate cancer patients has not been sufficiently elucidated despite evidence that acute myeloid leukemia is a consequence of therapeutic radiation in other primary malignancies. Therefore, we investigated the effect of definitive therapy with radiation therapy (external beam radiation therapy [EBRT] or brachytherapy) on acute myeloid leukemia incidence in a population-based cohort of patients with localized or locally advanced prostate cancer.

METHODS

We utilized the Surveillance, Epidemiology, and End Results database to identify a cohort of men (n=168,612) with newly diagnosed prostate adenocarcinoma between January 1988 and December 2003. Cox proportional hazard regression was used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) of acute myeloid leukemia incidence following definitive therapy with EBRT alone, brachytherapy alone, or surgery alone compared to no definitive therapy (i.e. no EBRT, brachytherapy, or surgery).

RESULTS

The cohort yielded 184 acute myeloid leukemia cases during 1,064,820 person-years of follow-up after prostate adenocarcinoma diagnosis. Patients treated with EBRT had a higher adjusted relative risk of developing acute myeloid leukemia than patients treated with brachytherapy or surgery when each therapy group was compared to patients who were not treated with definitive therapy (EBRT: HR=2.05, 95% CI 1.29, 3.26; brachytherapy: HR=1.22, 95% CI 0.46, 3.22; surgery: HR=1.24, 95% CI 0.77, 1.98).

CONCLUSIONS

Our findings suggest that acute myeloid leukemia incidence is a greater concern for patients treated with EBRT than brachytherapy for localized or locally advanced prostate adenocarcinoma.

Pictorial review: Unusual tumours involving the prostate: radiological-pathological findings

The appearance of several unusual tumours in the prostate has resulted in questions being raised concerning their histogenesis; moreover, some of these tumours have prognoses that are quite unlike those of prostatic adenocarcinoma. Unusual neoplasms involving the prostate have been described in recent years, including mucinous cystadenocarcinoma, neuroendocrine cancer, lymphoma, spindle cell neoplasm, squamous cell carcinoma and transitional cell carcinoma. Radiological findings can overlap, and play limited roles in the diagnoses of these entities. However, knowledge of the radiological findings in these conditions can be helpful in making differential diagnoses. Images of prostate lesions using several imaging modalities, including transrectal ultrasound, MRI and CT, as well as available pathological images of such lesions, are presented in this article.

Advances in transrectal ultrasound imaging of the prostate

Grayscale imaging of the prostate is the basic method for diagnostic evaluation and biopsy guidance. Doppler imaging may improve sensitivity for detection of prostate cancer. Microbubble contrast agents represent a major advance to more selectively demonstrate neovascular flow within the prostate. Recently, real-time elastography has been introduced to improve detection of cancer based upon changes in tissue stiffness. As diagnostic methods improve, the ultimate hope is to eliminate biopsy in patients without cancer. New ultrasound-based treatment systems, such as high-intensity focused ultrasound ablative therapy for prostate cancer, may someday allow diagnosis and treatment of prostate cancer to be completed in one sitting.

Primitive neuroectodermal tumour of the prostate gland: ultrasound and MRI findings

We report a rare case of primitive neuroectodermal tumour (PNET) of the prostate occurring in a 26-year-old man with a mass replacing the prostate gland in the absence of any lesion involving the bone and soft tissues. To our knowledge, there is no radiological literature that has described the imaging findings in a case of PNET of the prostate. Imaging findings in cases of PNET of the kidney are described in the literature. On ultrasound, the mass appeared multilobulated and multinodular with intratumoural heterogeneity. No brightly reflective echoes with posterior acoustic shadowing to suggest calcification were noted. MRI revealed a heterogeneous lobulated mass with irregular septae within. The mass showed low signal intensity on T(1) weighted images and appeared heterogeneous on T(2) weighted images. Haemorrhage and necrosis were also seen in the tumour.

Hematospermia: imaging findings

Hematospermia is an anxiety provoking but otherwise generally benign and self-limited condition that is infrequently associated with significant underlying pathology, and is most often considered to be idiopathic in nature. Management with routine clinical evaluation, watchful waiting, and reassurance generally suffice without further diagnostic workup or treatment. Noninvasive imaging may play an important role in the diagnostic workup of men with hematospermia, particularly in those who are >40 years old, have other associated symptoms or signs of disease, or have persistence of hematospermia. Many entities may be encountered in association with hematospermia at imaging, and specific therapeutic interventions may be used if certain treatable underlying pathologies are coincidentally detected. In this comprehensive review, we discuss the potential etiologies, diagnostic workup, imaging techniques, relevant male pelvic anatomy, imaging appearance of specific associated pathologies, and treatment for hematospermia.

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.

Rare case of carcinoid tumor arising within teratoma in kidney

Not all enhancing lesions in the kidney are renal cell carcinoma. We report a rare case of a carcinoid tumor arising within a teratoma of the kidney in an asymptomatic female patient. Carcinoid tumors and teratomas involving the kidneys are rare. The two entities existing simultaneously in the same kidney are exceptionally unique. Still, the radiographic characteristics of these lesions have been previously described and should be familiar to practicing physicians.

Imaging clinically localized prostate cancer

At this time there is no highly sensitive and specific widespread radiographic test for local staging of prostate cancer. Future developments will likely require a combination of imaging modalities with utilization guided by risk-stratification models (Table 4). Staging data for all imaging tests discussed in this article are summarized in Tables 5 and 6. Clinically, conventional gray-scale TRUS remains the most frequently used tool because of its utility in guiding prostatic biopsies. Modifications of TRUS--including power and color Doppler, 3D imaging, and new ultrasound contrast agents and elastography--show promise in increasing the accuracy of ultrasound. Endorectal MRI may have some value for staging selected patients. The addition of prostatic MRS, which images the differential activity of metabolites, may increase the specificity of MRI. Newer techniques with finer voxel resolution may prove to be clinically useful. A large well-designed study evaluating the utility of MRI/MRS is currently being planned. Cross-sectional imaging of the pelvis with either MRI or CT should be used selectively as should radionuclide bone scans. Similarly, ProstaScint scans should be ordered selectively, either before or after primary therapy, rather than routinely in all patients.

The role of transrectal ultrasound in diagnosing prostate cancer

The availability of the prostate-specific antigen test to screen for prostate cancer has caused a significant workload burden for urologists and radiologists alike. Prostate cancer is common in our aging population and most cancers are now definitively detected by transrectal ultrasound (TRUS)-guided prostatic needle biopsy. TRUS alone has limited potential to identify prostatic cancer because of frequent multifocality of cancer within the prostate, the variable sonographic appearance of prostatic tumors, the poor specificity of focal ultrasonic abnormalities, and the substantial percentage of isoechoic prostate cancers (which cannot be differentiated from adjacent benign tissues with imaging). Developments in TRUS equipment over the past decade include the use of color and power Doppler, higher frequencies, broad bandwidth technologies, and harmonic, contrast harmonic, and pulse inversion imaging. All of these improvements may enhance detection of subtle focal sonographic abnormalities within the prostate. Ultrasonic contrast agents can aid the visualization of subtle alterations in prostatic echotexture by highlighting changes in microvasculature. It is possible that Doppler techniques and contrast agents have the potential to reveal prognostic information about cancer in individual patients.

Prostate carcinoma with neuroendocrine differentiation: case report and literature review

Neuroendocrine differentiation in prostatic carcinomas generally confers a more aggressive clinical behavior and less favorable prognosis than usual prostatic carcinomas. In this manuscript, we report a case of a 58-year-old man with prostatic carcinoma who died 1 year after initial diagnosis. Autopsy showed a disseminated prostatic carcinoma with neuroendocrine differentiation. There were metastasis to the spleen, an organ infrequently involved by disseminated epithelial neoplasms. Neuroendocrine differentiation was demonstrated by immunohistochemical studies in the biopsy and autopsy material.

Magnetic resonance imaging of the prostate

Magnetic resonance imaging has been shown to be more accurate than other imaging modalities in the evaluation of both malignancies and various benign lesions of the prostate. Despite its superiority, because of its cost and low availability, magnetic resonance imaging should play a role as a problem-solver secondary to computed tomography or ultrasonography. The routine use of magnetic resonance imaging in the staging of prostate cancer before surgery cannot be justified on the basis of published data. Magnetic resonance imaging has been proved to be of value in the planning and delivery of different types of radiotherapy to patients with prostate cancer. Through the use of combined magnetic resonance imaging and the new modality, magnetic resonance spectroscopy, the accuracy and specificity of tumour detection and the delineation of tumour extent can be improved. Magnetic resonance technology is rapidly evolving, and in the near future, new possibilities such as biological imaging will have a great impact on magnetic resonance imaging of the prostate.