Written informed consent was obtained from the patient for publication of this case report and accompanying images. Institutional Review Board permission was granted.
A 67-year-old male patient smoker (smokes 10 cigarettes/day) with BMI of 28.7 underwent transrectal needle biopsy of the prostate in July 2015 due to elevated prostate-specific antigen (PSA) level of 7.02 ng/mL and firm nodule with infiltration of the capsule on digital rectal examination. The patient had no previous history of faecal occult blood testing, prostate biopsies or surgeries performed. Biopsy revealed poorly differentiated ductal adenocarcinoma Gleason 4 + 4. Imunohistochemical analysis was positive for p504s and negative for PSA, CK20, CK7, and CDX2. The patient received hormonal treatment with Leuprorelin acetate for 9 months. Pelvic magnetic nuclear resonance imaging (MRI) showed tumour in both prostate lobes and infiltration to semi vesicles mrT3bN0 PI-RADS – 5 (Prostate Imaging Reporting and Data System). Staging of computed tomography (CT) of the abdomen and pelvis and Tc-99 m bone scan showed no radiological evidence of metastatic spread. Patient was advised to undergo surgery.
In October 2016, radical retropubic prostatectomy and ilio-obturator lymphonodectomy was performed. Pathological findings demonstrated poorly differentiated ductal adenocarcinoma (Gleason 4 + 5(40%) = 9) pT3bN0, LV1. PSA value 2 months after operation was 0,126 ng/ml and increased up to 0,358 ng/ml over four-month period which was stated as a recurrence. Patient was started on adjuvant intermittent androgen deprivation therapy combined with radiotherapy.
In August 2017, patient received 2 phase radiotherapy: first phase to prostate bed, remnant seminal vesicles and regional lymph nodes up to 50 Gy and second phase to prostate bed and remnant seminal vesicles up to 70 Gy. The PSA levels decreased, however 4 months later patient complained of mild pain in anal verge.
In May 2018, slight tenderness on 12 o’clock was noted during digital rectal examination. On rectoscopy the rectal and anal mucosa was found without any changes. Chest, abdomen and pelvic CT scan did not reveal any signs of recurrence.
In June 2018, the patient was admitted to the hospital complaining of dyschezia, pain in anal canal, and bloody stool. Anal inspection and palpation revealed an anal fissure with ulceration. A biopsy from ulcerated area was taken. Histologic examination reported poorly differentiated ductal adenocarcinoma of the prostate extending to muscle layer with NKX3.1, PSA, CKHMW, positive staining. MRI scan (Fig. 1) showed slightly enlarged rectum wall in anal canal with a slight increase of contrast accumulation and small nodules on the left rectum wall.
Because of anal pain, bloody stool, prostatic metastasis verified, and no evidence of distant metastases, the only metastasis was in the anal canal, patient underwent laparoscopic abdominoperineal resection (APR) in August 2018. Histopathologic findings from the resected specimen showed ductal prostate cancer at the dentate line extending to the fat tissue and infiltrating mucosa, submucosa and muscle layers of the anus (Figs. 2, 3, 4, 5, 6, 7, 8 and 9). One of five lymph node had prostate cancer metastasis. Post-operative course was uneventful and on post-operative day 7, patient was discharged. Patients PSA was less than 0.2 ng/ml.