Rare prostate tumors: beyond adenocarcinoma

Transcription

1 Rare prostate tumors: beyond adenocarcinoma Poster No.: C-0357 Congress: ECR 2015 Type: Educational Exhibit Authors: M. Diez Blanco, M. Drake Perez, E. Lopez Uzquiza, A. Lamagrande Obregon, A. De Diego Diez, V. Fernandez Lobo, B. Garcia Martinez, A. Fernández Flórez; Santander/ES Keywords: Urinary Tract / Bladder, Genital / Reproductive system male, Oncology, Ultrasound, MR, CT, Imaging sequences, Neoplasia DOI: /ecr2015/C-0357 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 16

2 Learning objectives 1).- To know the different types of neoplasm in the prostate, both frequent and rare. 2).- To present the essential imaging diagnostic attributes of these variants. 3).- To emphasize the clinical significance of these variants, when different from usual acinar adenocarcinoma, including clinical presentation and outcome. Background INTRODUCTION: The vast majority of prostatic tumors developing in adult males are adenocarcinomas. Some of the adenocarcinoma variants have specific clinical features and differential diagnoses. Furthermore, there has been some disagreement regarding the appropriate application of the Gleason grading scheme in these tumors. In other cases, there are no true neoformative prostatic processes, but inflammatory pseudotumor of origin. We present a review of the different types of classical adenocarcinoma, the variants of prostatic carcinoma, as well as our own experience, describing a case of prostate sarcoma, prostate malakoplakia and transitional cell carcinoma of prostate. OVERVIEW: When facing with a malignant tumor of the prostate, the most common etiology is acinar adenocarcinoma. But there are other possibilities; histologically, Page 2 of 16

3 these variants (incidence between 5-10%) can be grouped into 2 categories, variants of acinar adenocarcinoma and non-acinar ones. - The first group consists of the atrophic adenocarcinoma, pseudohyperplastic, foamy gland, colloid, signet ring cell, oncocytic and lymphoepithelioma-like. - The second group includes sarcomatoid carcinoma, ductal adenocarcinoma, urothelial carcinoma, squamous and adenosquamous carcinoma, basal cell and neuroendocrine tumors, specially small cell. New variants of prostatic carcinoma have been recently described since the 2004 WHO classification. They are microcystic adenocarcinoma, PIN (Prostatic Intraepithelial Neoplasia), PIN-like adenocarcinoma, large cell neuroendocrine carcinoma and pleomorphic giant cell carcinoma. Findings and procedure details Classification: 1. Acinar adenocarcinoma variants: 1.- ATROFIC Incidence of 2% in transrectal biopsies and 16% in the prostatectomy piece. Similar to the usual adenocarcinoma prognosis. Page 3 of 16

4 2.- PSEUDOHYPERTROPHIC This variant is responsible for incorrect biopsy results. Associated with usual acinar adenocarcinoma. The prognosis is not clearly established, but there is no difference between habitual adenocarcinona staging with or without pseudohypertrophic variant associated. 3.- COLLOID One of the most rare (incidence of 0.3% of all prostate cancers). It is an adenocarcinoma with at least 25% of extracellular colloid. Classically conferred a worse prognosis although recent studies indicate no differences in survival after radical prostatectomy. 4.- SIGNET RING CELLS The incidence is very low. Usually seen in patients with PSA>15 and advanced clinical stage. The prognosis is poor (survival of 28 months) and treatment response, including hormone Page 4 of 16

5 androgen deprivation therapy, is minimal. 5.- ONCOCITIC There are no significative difference in tumor prognosis than usual. 6.- LYMPHOEPITHELIOMA-LIKE Poorly differentiated carcinoma. They are patients with advanced stage and obstructive symptoms. Poor Prognosis. Survival between 8 and 26 months. 2. No acinar adenocarcinoma variants: A).- SARCOMATOID: Fig. 1 on page 9 Fig. 2 on page 10 Fig. 3 on page 11 Fig. 4 on page 11 It is a biphasic tumor presenting two components, one epithelial (carcinomatoid) and other mesenchymal (sarcomatoid). The carcinomatoid component is dominant only in one third of cases. Sarcomatoid differentiates commonly to osteosarcoma and chondrosarcoma. Patients frequently present obstructive symptoms. In the physical examination, prostate is large, nodular and hard and PSA levels are elevated. Macroscopically, it consists on large masses (55-180mm) with areas of hemorrhage and necrosis and signs of infiltration of nearby organs (seminal vesicles and rectum). Page 5 of 16

6 The prognosis is poor with a mean survival of 3 years and survival at 7 years of 14%. It is an aggressive entity with local recurrence and formation of large masses. Metastases are frequent in lung, bone, lymph nodes and brain. The only effective treatment is surgical. B).- DUCTAL CARCINOMA: One of the most common (incidence of 3.2% of all prostate cancers). Clinically, patients present with obstructive symptoms and hematuria, as well as suspicious prostate palpation and elevated PSA (PSA levels in the range of metastases do). 12% of cases present with metastases compared with 4% of the usual variant. Tipically protruding into the urethra at the veru montanum. Tendency to metastasize to testes, penis and lung. Worse prognosis than the usual adenocarcinoma. C).- TRANSITIONAL CARCINOMA: Also called urothelial, it is associated with primary tumor of the bladder or urethra. It has been reported to have direct intraprostatic extension from these organs, one implant from either of them or multifocal disease. It is difficult to differentiate in these cases the primary from the metastatic tumors. It has an incidence of 1.1% of all prostate cancers. In the past it was considered to have a poor prognosis (survival of 17 to 29 months) but now the situation has reversed. D).- SMALL CELL CARCINOMA: Very rare (0.3-1% incidence) and aggressive tumor. In 50% of the cases it is associated with adenocarcinoma. In its clinical presentation highlights a lower percentage of patients with elevated PSA, the tendency to metastasize quickly, its poor response to hormone therapy and its short survival (9 to 17 months). There has been reported paraneoplasic syndromes as Cushing, hypercalcemia, Inappropriate Secretion of Antidiuretic Hormone Syndrome, hyperparathyroidism, thyrotoxicosis, Eaton-Lambert and encephalitis. 92% of patients with small cell carcinoma have advanced disease and 75% metastasis (liver and lung). Atypical location of metastases are also characteristic (omentum, vocal cords, temporal bone...). Slight bone Page 6 of 16

7 involvement in patients with metastases at multiple sites, makes suspect this entity. 3. Prostatic carcinoma variants described after the WHO 2004 classification 1.- MICROCYSTIC ADENOCARCINOMA 2.- PIN LIKE ADENOCARCINOMA 3.- LARGE-CELL NEUROENDOCRINE CARCINOMA 4.- PLEOMORPHIC GIANT -CELL ADENOCARCINOMA Except for the former that appears in 11% of surgical specimens, the rest entities are very rare, without distinguishing characteristics, except for the particularly poor prognosis, with the exception of the latest MICROCYSTIC ADENOCARCINOMA: It is characterized by cystic dilatation and rounded expansion of glands of usual acinar adenocarcinoma, with a flat luminal lining layer. It represents a form of atrophic and # or pseudohyperplastic variants. The incidence in adenocarcinomas in whole prostate glands is approximately 11%. Microscopically, the mean glandular size of microcystic adenocarcinoma is 10-fold greater than that of usual small acinar adenocarcinoma. Intraluminal crystalloids and intraluminal blue mucin are seen in all cases. 2.- PIN-LIKE ADENOCARCINOMA: It is a recently described growth variant of adenocarcinoma of the prostate that resembles PIN (Prostatic Intrapithelial Neoplasia) in gland architecture. Clinically, patients are similar to those with usual acinar adenocarcinoma in age (mean 68 years) and clinical presentation, with an elevated serum PSA level (mean 5.9 ng # ml). At radical prostatectomy, an associated but physically separate component of usual acinar adenocarcinoma (of Gleason score 6) may be seen. 3.- LARGE-CELL NEUROENDOCRINE CARCINOMA: Page 7 of 16

8 This is an extremely rare variant with histological features identical to those of large-cell carcinoma in the lung. Among the very few cases thus far reported, some patients had a history of adenocarcinoma treated with hormonal therapy. The mean age was 67 years (range years). Microscopically, sections showed sheets and ribbons of cells with large nuclei with coarse chromatin and prominent nucleoli. Mitotic activity and tumoral necrosis were prominent. The prognosis is poor: the mean survival was 7 months. 4.- PLEOMORPHIC GIANT-CELL ADENOCARCINOMA: This is an exceptionally rare variant of adenocarcinoma with giant pleomorphic nuclei. Few cases have been reported. In the largest series, patients ranged in age from 59 to 76 years. Gleason score 9 is usually seen in many cases of adenocarcinoma. The disease course is very aggressive. 4.- Pseudotumoral lesions A).- INFLAMMATORY PSEUDOTUMOR: It is a rare disease of unknown etiology. The genitourinary tract, bladder and prostate are the most common sites committed, while renal localization is rare. The presentation is very nonspecific and can develop renal mass, back pain, hematuria, urinary tract infection, fever and renal failure. It is a disease that occurs in young men, with a mean of 35 years. Usually shows a benign behavior, although metastasis and local recurrence are reported. Although the radiologic features of pseudotumor are nonspecific, some features have been described as hypo or hyperechoic lesions with illdefined borders and prominent vascularization. In the CT are shown as homo / heterogeneous lesions of varying density. On MRI it appears as hypointense lesions on T1 and T2 with marked enhancement after gadolinium administration. B).- MALAKOPLAKIA (MLP): Fig. 5 on page 12 Fig. 6 on page 13 Fig. 7 on page 13 Fig. 8 on page 13 Page 8 of 16

9 It is a chronic granulomatous disease, apparently caused by a defect in the bacterial phagocytic system. It is a rare entity characterized by the presence of one or more tumors anywhere in the body, hence the confusion of his diagnosis with malignancy. Tissues typically involved are consistent with a massive infiltration of inflammatory cells (macrophages and histiocytes) with intracytoplasmic inclusions characteristics (Michaelis-Gutmann bodies). Usually self-limited and associated with repeated urinary infections, with excellent response to prolonged treatment with quinolones. Multiple theories have been proposed to explain the pathogenesis of this disease. An infectious origin, a state of immunosuppression, a neoplasm, or systemic disease corresponds to a genetic disorder is described. The urinary tract is the place most commonly affected by the MLP and is well documented that 80-90% of patients suffer from persistent infection with coliform organisms. The genitourinary disease is more common in females (4:1) with a peak incidence in those over 50 years, although the age range of affected patients provided ranges from 6 weeks old to 85 years. There is no clinical nor radiological characteristic picture of the disease. Usually presents with diffuse abdominal pain, weight loss, diarrhea, hematochezia, hematuria and fever (the symptoms depend on the organ involved). The prostate implication is a rare disease and it causes a hard gland in palpation and PSA elevations. The disease is difficult to diagnose only taking into account the clinical and imaging findings, as they are nonspecific. They are lesions that simulate malignancy, with infiltrative and capable features mass forms that grow in the pelvic fat and can infiltrate not only viscera but also cause bone destruction. Definitely, the diagnosis is histopathological, so the biopsy is essential for confirmation as well as to exclude other pathologies. The mainstay of treatment is prolonged antibiotic. Fluoroquinolones are effective in 80 to 90%. Rifampicin, trimethoprim-sulfamethoxazole and gentamicin are also described. The prognosis is usually favorable, although it is not always a benign process, as in situations of extravesical involvement it may be an aggressive disease with potentially fatal complications. Surgery is limited to situations where conservative treatment is ineffective. Images for this section: Page 9 of 16

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15 Conclusion Although the incidence is low, it is important to know that not all prostate tumors correspond to adenocarcinoma, since not all have the same clinical behavior. Some have a very aggressive growth, as prostate sarcoma, and others are stable and even they may disappear with appropriate antibiotic treatment as in the case of malakoplakia. Radiologists play an important role as imaging studies are especially important in the early diagnosis of these entities, improving the prognosis of these patients. Personal information Thank you for visiting my poster!. If you need to contact me, please write to me in: maria.diez.blanco@gmail.com References Linda C. Chu, Hillary M. Ross, Tamara L. Lotan, Katarzyna J. Macura, AJR American Journal of Roentgenology 2013; 200: W571-W580. Prostatic Stromal Neoplasms: Differential Diagnosis of Cystic and Solid Prostatic and Periprostatic Masses. Peter A Humphrey. Histopathology 2012, 60, DOI: / j x Histological variants of prostatic carcinoma and their significance. Sung Bin Park, Kyoung-Sik Cho, Jeong Kon Kim, Jong Hwa Lee, Ae Kyung Jeong, Woon Jung Kwon, Hak Hee Kim. AJR 2008; 191: Inflammatory Pseudotumor (Myoblastic Tumor) of the Genitourinary Tract. David J Grignon; Modern Pathology (2004) 17, Unusual subtypes of prostate cancer. Page 15 of 16

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