Neurofibromatosis with involvement of the prostate gland

Prostatic stromal proliferations: a review

Prostatic stromal proliferations account for the majority of benign tumour-like lesions in the prostate. The most common is nodular hyperplasia, seen in a majority of elderly men. Diagnostic difficulty is encountered with some variants, including stromal hyperplasia with atypia, characterised by degenerative changes of myofibroblasts. In contrast with benign stromal tumours, malignant stromal tumours of the prostate are rare, accounting for less than 0.1% of all prostatic malignancies. The most common are rhabdomyosarcoma (paediatric) and leiomyosarcoma (adults); others include phyllodes tumour and stromal sarcoma. Some authors lump malignant tumours with poor outcome (e.g., phyllodes tumour and stromal sarcoma) with benign stromal tumours (e.g., stromal hyperplasia with atypia, leiomyoma), considering them collectively to be of uncertain malignant potential, but this approach is discouraged. This review presents a contemporary approach to classification and diagnosis of prostatic stromal tumours.

Malignant Peripheral Nerve Sheath Tumor of Prostate: A Rare Case Report and Literature Review

A mid-aged male presented with progressive lower urinary tract symptoms (LUTS) for years. Huge prostate with low serum prostate-specific antigen (PSA) level was detected. The specimen from transurethral resection revealed surprising pathology finding as malignant peripheral nerve sheath tumor (MPNST). Considering its huge size (more than 300 gm) and location, we prescribed neoadjuvant chemotherapy firstly. The tumor became regressive and then radical surgical resection was achieved. Adjuvant multimodality treatment including concurrent chemoradiotherapy (CCRT) and target therapy was given. However, he expired about one year later. MPNST originating from prostate is very rare and seldom reported before. We here present this extremely rare disease and share our treatment experience.

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.

Non-epithelial neoplasms of the prostate

Non-epithelial prostatic neoplasms are infrequent and cover a broad array of entities that include both benign and highly aggressive tumours. Because they are very infrequent, there is often limited understanding of them, and the recognition of these entities, when encountered, may pose a diagnostic challenge, owing to histological overlap between them or their rarity. Most lesions in this category are mesenchymal in origin, such as prostatic stromal tumours arising from specialized prostatic stroma, smooth muscle tumours, both benign and malignant, and solitary fibrous tumours. Less commonly occurring tumours include neural, germ cell and melanocytic tumours that may be derived from cells not normally present in the prostate. Some tumours have well-established extraprostatic counterparts and, when encountered, are more commonly extraprostatic/secondary in origin; these include gastrointestinal stromal tumours and most haematopoietic tumours. The majority of tumours are characterized by a spindle cell pattern with significant overlap in morphological features. In this setting, appropriate use of immunohistochemistry and molecular studies are often necessary for accurate diagnosis, prognosis, or prediction for therapy. This review addresses and updates the clinicopathological features of the entire spectrum of non-epithelial tumours with an approach to the histological diagnosis.

Mesenchymal Tumors of the Prostate

Prostatic mesenchymal tumors encompass various benign and malignant neoplasms that may derived from the intrinsic prostatic stroma or from associated elements including muscle, connective tissue, blood vessels, and neural structures. The differential diagnosis of these tumors is broad and encompasses prostatic epithelial processes that demonstrate prominent spindle cell morphology, as well as mesenchymal tumors that secondarily involve the prostate. Careful morphologic examination, clinical history, and judicious use of a limited panel of immunohistochemical markers and molecular tests aid in the proper diagnosis of these lesions. This article provides a structured guide for the analysis and diagnosis of both benign and malignant prostatic mesenchymal lesions and highlights key features that distinguish these entities within the differential diagnosis of prostatic spindle cell lesions.

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.

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.

Imaging the Pediatric Prostate

The prostate gland is not often the target of imaging in children but may be imaged during investigation of symptoms related to the lower genitourinary tract such as hematuria, urinary retention, dysuria, and incontinence or during an evaluation for suspected congenital anomalies. Ultrasound and voiding cystourethrography are useful for initial evaluation of congenital and neoplastic disorders of the prostate. MR imaging and CT are useful in delineating more detailed anatomy before surgical planning and in determining the organ of origin in a patient who has a large pelvic mass.

Tuberous sclerosis complex and neurofibromatosis type 1: the two most common neurocutaneous diseases

TSC and NF1 are the most common of the neurocutaneous diseases, and both are autosomal dominant with a high spontaneous mutation rate. For diagnosis, two features are necessary for each disease. Skin findings for each are especially helpful for diagnosis, as is neuroimaging in TSC. For NF1, neuroimaging is not yet reliable for diagnosis. In children, brain symptoms cause most of the morbidity in TSC, and nerve sheath and nervous system tumors as well as learning disabilities cause major morbidity in NF1. Renal disease becomes a serious problem for adults with TSC. The TSC1, TSC2, and NF1 genes function as tumor suppressor genes and have other functions that are being investigated. Blood tests for diagnosis have a high false-negative rate. Therapies for TSC and for NF1 are both medical and surgical.

Tuberous sclerosis complex and neurofibromatosis type 1: the two most common neurocutaneous diseases

TSC and NF1 are the most common of the neurocutaneous diseases, and both are autosomal dominant with a high spontaneous mutation rate. For diagnosis, two features are necessary for each disease. Skin findings for each are especially helpful for diagnosis, as is neuroimaging in TSC. For NF1, neuroimaging is not yet reliable for diagnosis. In children, brain symptoms cause most of the morbidity in TSC, and nerve sheath and nervous system tumors as well as learning disabilities cause major morbidity in NF1. Renal disease becomes a serious problem for adults with TSC. The TSC1, TSC2, and NF1 genes function as tumor suppressor genes and have other functions that are being investigated. Blood tests for diagnosis have a high false-negative rate. Therapies for TSC and for NF1 are both medical and surgical.

Indium-111 capromab pendetide (ProstaScint) uptake in neurofibromatosis

We report on the demonstration of nonspecific accumulation of indium-111 capromab pendetide (ProstaScint) in neurofibromas in a patient with a rising prostate-specific antigen level after prostatectomy. Although the immunoconjugate is targeted to a specific membrane antigen present in human prostate carcinoma, nonspecific uptake can occur in other entities. Indium-111 capromab pendetide scintigraphy is a valuable diagnostic tool that should always be interpreted within the context of the clinical history and the laboratory and radiologic findings to avoid misinterpretation.