轉移性攝護腺癌完治後繼發黃色肉芽腫性攝護腺炎:極少見個案報告及文獻回顧
楊哲學、呂謹亨、黃立華、歐宴泉、許兆畬、童敏哲
台中童綜合醫院 外科部 泌尿科
Successive Xanthogranulomatous Prostatitis after Cure of Metastatic Prostate Adenocarcinoma: An Extremely Rare Case Report with Review of Literatures
Che-Hsueh Yang, Chin-Heng Lu, Li-Hua Huang, Yen-Chuan Ou, Chao-Yu Hsu, Min-Che Tung
Division of Urology, Department of Surgery
Tungs’ Taichung MetroHarbor Hospital, Taichung Taiwan
Case: The 70-year-old healthy man initially bothered by voiding lower urinary tract symptoms (LUTS) of weak stream and intermittency. He went to LMD at first. DRE showed hard and immobile texture and Prostate Specific Antigen (PSA) was detected 200 ng/ml. Trans-Rectal Ultrasound Guided biopsy (TRUS-biopsy) performed and the report said adenocarcinoma with Gleason score 4+5. Prostate volume was around 30 grams. Computed tomography demonstrated several lymphadenopathy and metastatic bone lesions. Androgen Deprivation Therapy (ADT) of Leuprorelin was administrated. PSA was suppressed to 11.25 ng/ml.
Afterward, he visited our hospital due to LUTS deterioration and PSA elevated to 52.427 ng/ml. Testosterone was 9.270 ng/ml. Prostate volume of 37.3 cm3 with protruding into the bladder was seen on ultrasound. Palliative Transurethral Resection of the Prostate (TURP) was performed, yielding total resected 39 grams of pour nodular hyperplasia. Triptorelin 11.25 mg every 12 weeks and Bicalutamide 50mg per day were given. Specimen from TURP showed nodular hyperplasia. Repeated contrast computed tomography revealed lymph nodes regression. Whole body bone scan showed still active bone lesion at L2 and left pubic bone. PSA was down to 0.015 ng/ml under ADT treatment.
After share decision making with the patient and family, robotics-assisted radical prostatectomy (RARP) with neurovascular bundle preservation was performed. After 220 minutes operative time and 100 ml blood loss, 30 grams of prostate was resected. Grossly, it looked brown coloration and touched like rubbery with partly firm. Microscopically, it was constructed of nodular hyperplasia and xanthogranulomatous prostatitis. Immunohistochemical stains were seen with CD68+++ and negative PSA. Alpha-methylacyl-CoA racemase (AMACR) stain showed positive, hinting atrophic degenerative crowded benign acinar cells confined in prostatitis zone. The inflammatory foamy cells showed abundant vacuolated foamy cytoplasm, small uniform, benign appearing nuclei, and small inconspicuous nucleoli and mixed some benign giant cells. Total of 14 lymph nodes coming from pre-prostatic and bilateral obturator areas were all free of metastatic worries. Based on the pathological reports, xanthogranulomatous prostatitis (XGP) was impressed.
Discussion: XGP, a subtype out of granulomatous prostatitis, is a rare occasion but imitate the prostate cancer in every aspect, spanning from clinical manifestations to laboratory evidence. It is an inflammatory disease originating from fungi, bacteria, virus, and even parasites. The most seen pathogens are Mycobacterium tuberculosis, blastomycosis, coccidioidomycosis, and cryptococcosis. Some factors, such as diabetic mellitus and immunosuppressant status, can predispose to it. Various ways of classifications are applied, and, according to their causative and histological features, it can be roughly diverged to specific or non-specific type.
First report of granulomatous prostatitis can be traced back to about 70 years ago by Tanner and McDonald with only 3% among inflammatory causes. Harsh Mohan et al. had collected 1353 prostatic cases across 8 years. Among 1196 cases of benign specimen, only 20 of them were granulomatous prostatitis, that’s 1.4%, and 2 out of 20 were XGP, which is 0.1%. Telling the difference between XGP and prostate cancer is decisive in therapeutics purpose.
Contemporary diagnosis of prostate cancer relied on three major components that are digital examination (DRE), PSA, and TRUS-biopsy. However, XGP can totally simulate these three and subsequently been included into diagnosis of cancer, in the end, impeding an urologist from correct thinking process. Clinically speaking, patients with XGP usually are at their 5 to 6 decades, feeling nothing but LUTS. Physical examination shows hard nodule just like a cancer in DRE, and of course the PSA commonly surges, which reported from 0.5 ng/ml to 200 ng/ml based on published literatures, being one of the characteristics of an inflammatory process. TRUS-biopsy in most cases makes XGP give way to a real cancer diagnosis. Harsh Mohan et al. reported 20 cases of granulomatous prostatitis, only 1 of them was prescribed with simultaneous prostate adenocarcinoma after prostatectomy, featuring irritative and obstructive voiding symptoms, fixed hard nodule on DRE and PSA of 50.9 ng/ml. Hiroki Takizawa et al. well demonstrated how important it is to obtain tissues as much as possible to rule out the malignancy and to avoid unnecessary invasive surgery. When talking about diagnostic alternatives, case report from Hsiang-Ying Lee el al. even demonstrated how a XGP escapes from the diagnosis under a magnetic resonance imaging (MRI) modality, which is one of the most popular auxiliary diagnostic ways besides Prostate Health Index (PHI).
The importance of this case lies in complete regression of high grade metastasis prostate adenocarcinoma to XGP after ADT. To date, this is the first published case of XGP originated from hormone treated prostate adenocarcinoma. There was a dilemma of this malignant-to-benign change. The pathology report of TURP before RARP, slicing over half of prostate volume down, only discloses nodular hyperplasia. The result cannot rule out the possibility of residual prostate cancer. In addition, ADT treatment may further shade the PSA rising RARP was the only method to confirm complete regression of prostate cancer.
This rare case, on a practical basis teaches us that, from the past published literatures, the most precise tool to distinguish XGP or any other granulomatous prostatitis from cancer is tissues’ evidence. Furthermore, there is still the possibility of complete regression of prostate cancer after ADT.