Endoscopic mastectomy followed by immediate breast reconstruction with fat grafting for breast cancer.

BACKGROUND: Although endoscopic mastectomy has been associated with good tolerance and enhanced patient satisfaction, limitations such as the implant or flap size for reconstruction with small incisions remain unresolved. Fat grafting (FG) can expand tissue volume with pinhole skin incisions. Herein, we evaluated the safety and efficacy of endoscopic mastectomy followed by immediate FG. METHODS: Patients who underwent endoscopic mastectomy with immediate FG reconstruction from 2015 to 2021 were retrospectively evaluated to establish surgical outcomes and prognosis. RESULTS: Twenty-three patients with clinical stage 0 or I breast cancer underwent unilateral endoscopic mastectomy with immediate FG. The median age was 45 years (41-55), and the median body mass index was 19.3 kg/m2 (15.8-26.6). Endoscopically performed procedures included skin-sparing mastectomies in 18 patients (78%) and nipple-sparing mastectomies in five patients (22%). The median procedure duration was 295 min (242-346). The median specimen weight was 133 g (71-334), and the median grafted fat volume was 200 mL (136-320). No patient required reoperation or additional procedures for complications. One patient experienced recurrence at a median follow-up of 56.1 months and underwent resection; the patient was alive without recurrence 54 months post-resection. CONCLUSION: To the best of our knowledge, this is the first report of endoscopic mastectomy with immediate FG for reconstruction. When compared with other immediate autologous reconstructions, our strategy could minimize the skin incision and procedure duration, as well as limit complications. Further prospective investigations are needed to evaluate oncological safety, surgical outcomes, and patient satisfaction.

Case Report: The value of contrast-enhanced ultrasound and contrast-enhanced computed tomography in the diagnosis of hepatic angiosarcoma.

Background: Enhanced imaging techniques have the overwhelming advantages of being noninvasive and sensitive enough to evaluate the microcirculation of lesions, thus making them accurate in the diagnosis of hepatic lesions. Unfortunately, there is very little research on and knowledge of the imaging features of a rare cancerous condition: hepatic angiosarcoma (HA). Case summary: In this study, we retrospectively collected the data of six patients who underwent both contrast-enhanced ultrasound (CEUS) and contrast-enhanced computed tomography (CECT), and subsequently obtained a definitive histopathologic diagnosis of HA. We described the imaging appearances of HA by comparing CEUS and CECT images. Furthermore, we analyzed these imaging characteristics from the perspective of histopathology and tumorigenesis. The study included the largest number (six) of histopathologically confirmed HA patients who had received CEUS examinations to date. Conclusion: By offering readers comprehensive knowledge of contrast imaging, especially CEUS, in the diagnosis of HA, our study may reduce misdiagnosis and further improve treatment options.

Clinicopathological Characteristics and Prognosis of Triple-Negative Apocrine Carcinoma: A Case-Control Study.

Background: With a prevalence of only 1% among all breast cancers in Japan, apocrine carcinoma (AC) is a rare type of breast cancer, and its clinicopathological characteristics remain unclear. The aim of this study was to evaluate the characteristics and prognosis of AC, in relation to the presence or absence of androgen receptor (AR). Methods: We conducted a retrospective multi-center case-control study (Yokohama Clinical Oncology Group (YCOG): YCOG1701 study) in Japan. A total of 53 patients were registered who were diagnosed with AC between 2000 and 2017 in YCOG-affiliated hospitals. Results: The median age of the patients was 67 (43 - 94) years, and the median observation time was 6.1 years. Among the 53 cases, 24 had triple-negative pure AC (TN-PAC; AR-positive), whereas 29 had other types of AC (other-AC; estrogen receptor-positive and/or human epidermal growth factor receptor 2-positive or AR-negative). Tumor size was smaller (1.4 vs. 2.1 cm, P = 0.024) and metastasis occurred in fewer nodes (12.5% vs. 37.9%, P = 0.036) in the TN-PAC group than in the other-AC group. The number of patients who were administered perioperative adjuvant chemotherapy did not significantly differ between the two groups (TN-PAC/other-AC = 50.0%/55.2%, P = 0.525); however, there was no recurrence in the TN-PAC group, compared to five cases with relapse in the other-AC group. Conclusions: AR-positive AC patients showed a favorable prognosis without adjuvant chemotherapy, even with the TN subtype. A clinical trial exploring the possibility of treatment de-escalation is anticipated.

Fulminant Amebic Enteritis in the Perinatal Period.

Pregnancy is a known risk factor for amebic enteritis, which develops into potentially fatal fulminant amebic enteritis in some cases. We describe a case of a 27-year-old non-immunosuppressed pregnant woman with fulminant amebic enteritis complicated with cytomegalovirus enteritis. She improved with intensive care and intravenous metronidazole and ganciclovir but eventually required subtotal colectomy for intestinal stenosis. It is difficult to diagnose amebic enteritis, especially in a non-endemic area. Amebic enteritis must be considered as a differential diagnosis for refractory diarrhea with bloody stools in women in the perinatal period, even those without immunosuppression.

[Long-Term Survival after Surgical Resection for Small Cell Neuroendocrine Carcinoma of the Gallbladder].

A 60-year-old woman was not accompanied by any symptom. She had a gallstone which was identified 20 years prior. Ultrasonography performed by a local doctor revealed that the gallbladder was filled with small stones, and the patient was referred to our department for further examination and treatment for gallbladder stone. Tumor markers are elevated. Contrast- enhanced CT revealed gallbladder stones and thickening in the gallbladder body. PET-CT showed abnormal accumulation of FDG-PET with SUVmax 3.6 in the body of the gallbladder. With a diagnosis of gallbladder cancer, extended cholecystectomy and gallbladder bed resection with regional lymph node dissection were performed. The tumor was diagnosed histologically as small cell type neuroendocrine carcinoma of the gallbladder(pT2a[SS], pN0, pStage ⅡA; Japanese society of hepato-biliary-pancreatic surgery, the 7th edition). The postoperative course was uneventful. This patient has been followed up for 8 years without obvious signs of recurrence. R0 resection and lack of lymph node metastasis can allow long- term survival.

Clinicopathological features of PD-L1 protein expression, EBV positivity, and MSI status in patients with advanced gastric and esophagogastric junction adenocarcinoma in Japan.

This real-world study examined the prevalence of programmed death ligand-1 (PD-L1) expression and assessed the frequency of microsatellite instability-high (MSI-H) status and Epstein-Barr virus (EBV) positivity in Japanese patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma. This multicenter (5 sites), retrospective, observational study (November 2018-March 2019) evaluated Japanese patients with advanced gastric and GEJ adenocarcinoma after surgical resection (Stage II/III at initial diagnosis) or unresectable advanced cancer (Stage IV). The primary objectives were prevalence of PD-L1 expression (combined positive score [CPS] ≥1), MSI status, and EBV positivity. Tumor specimens of 389/391 patients were analyzed (male, 67.1%; mean age, 67.6 ± 12.2 years); 241/389 (62%) were PD-L1 positive, 24/379 (6.3%) had MSI-H tumors, and 13/389 (3.3%) were EBV positive. PD-L1 expression was higher in tumor-infiltrating immune cells than in tumor cells for lower CPS cutoffs. Among patients with MSI-H tumors and EBV-positive tumors, 19/24 (79.2%) and 9/13 (69.2%), respectively, were PD-L1 positive. A greater proportion of patients with MSI-H tumors (83.3% [20/24]) were PD-L1 positive than those with MSI-low/stable tumors (60.8% [216/355]; p = .0297); similarly, an association was observed between history of H pylori infection and PD-L1 expression. A higher proportion of patients with MSI-H tumors demonstrated PD-L1 expression with a CPS ≥10 (66.7% [16/24]) vs those with MSI-low/stable tumors (24.8% [88/355]; p < .0001). The prevalence of PD-L1 positivity among Japanese patients was comparable to that in previous pembrolizumab clinical trials and studies in gastric cancer. Particularly, higher PD-L1 expression was observed in MSI-H tumors.

Primary breast lymphoma initially diagnosed as invasive ductal carcinoma: A case report.

A malignant tumor in the breast may not be conclusive of breast cancer. It is important to keep the possibility of primary breast lymphoma in rare scenarios. For the diagnosis of primary breast lymphoma, immunohistochemical staining is necessary.

Bromodomain-containing Protein 4 Is a Favourable Prognostic Factor in Breast Cancer Patients.

AIM: To evaluate the association between bromodomain-containing protein 4 (BRD4) expression and clinicopathological factors and prognosis in human breast cancer specimens. PATIENTS AND METHODS: We used tissue microarrays constructed from samples of patients (n=183) who underwent surgery. We validated the association between BRD4 expression and prognosis in solid tumours, including breast cancer, using The Cancer Genome Atlas (TCGA) database. RESULTS: Immunohistochemical staining showed that BRD4 was widely distributed in breast cancer tissues. BRD4 was strongly expressed in 19.7% of patients but BRD4 staining intensity was not correlated with other clinicopathological factors. Most importantly, patients with a strong BRD4 expression had a significantly longer disease-specific survival than those with a weak BRD4 expression (100.0% vs. 91.3% at 5 years, p=0.027). mRNA expression analysis showed similar results (91.2% vs. 80.2% at 6 years, p=0.047). CONCLUSION: Strong BRD4 expression was associated with a significantly better prognosis in breast cancer tumours.

First-line Gemcitabine Versus Treatment of Physician's Choice for Metastatic Breast Cancer: A Prospective Cohort Study.

BACKGROUND/AIM: This study aimed to investigate the efficacy of first-line gemcitabine monotherapy for metastatic breast cancer (MBC) and its effect on health-related quality of life (HRQoL) compared with treatment of physician's choice (TPC). PATIENTS AND METHODS: We enrolled 96 patients into the first-line gemcitabine group (n=47) or other treatment of physician's choice (TPC) group (n=49) from May 2010 to April 2013. HRQoL was evaluated every 4 weeks. RESULTS: There was no significant difference in the median time to treatment failure (5.3 vs. 4.6 months, hazard ratio=0.87, p=0.546) and the incidence rates of grade 3/4 haematological toxicity (10.6% vs. 8.1%, p=0.677) and grade 3/4 non-haematological toxicity (4.2% vs. 8.1%, p=0.429) between the gemcitabine and TPC groups. Changes in HRQoL from baseline to 12 weeks were not significantly different. CONCLUSION: Gemcitabine achieves similar efficacy and HRQoL benefit to other chemotherapy and can be used as first-line treatment for MBC.

Liver regeneration after performing associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS) is histologically similar to that occurring after liver transplantation using a small-for-size graft.

PURPOSE: Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) can achieve marked future liver remnant (FLR) hypertrophy but this procedure is associated with a risk of mortality due to liver failure because of an insufficient FLR functional increase, a situation comparable to small-for-size syndrome (SFSS) after living-donor liver transplantation (LDLT). METHODS: The clinical data, morphologic volume changes, and histopathologic and immunohistochemical findings in hepatocytes and bile ductules were compared between ALPPS (n = 10) and LDLT with a risk for SFSS (n = 12). RESULTS: Although the patient characteristics and short-term outcome differed between the groups, the mean hypertrophy ratios with respect to liver volume for the FLR after performing the first-stage ALPPS procedures resembled those in small-for-size grafts after similar time intervals: 1.702 ± 0.407 in ALPPS vs. 1.948 ± 0.252 in LDLT (P = 0.205). The histologic grades for sinusoidal dilation (P = 0.896), congestion (P = 0.922), vacuolar change (P = 0.964), hepatocanalicular cholestasis (P = 0.969), and ductular reaction (P = 0.728) within the FLR at the second-stage operation during ALPPS or implanted graft were all similar between the groups. CONCLUSIONS: The hepatic regenerative process may be similar in ALPPS and LDLT using a small-for-size graft. Reducing the hepatic vascular inflow that may be excessive for the FLR volume during the first stage of ALPPS might enhance the functional recovery since measures with a similar effect appear to lessen the likelihood of SFSS.

Aldehyde Dehydrogenase 1-related Genes in Triple-negative Breast Cancer Investigated Using Network Analysis.

BACKGROUND/AIM: Aldehyde dehydrogenase 1 (ALDH1) is known as a breast cancer stem cell (CSC) marker. This study aimed to identify genes associated with ALDH1. MATERIALS AND METHODS: ALDH1-positive and -negative breast cancer cells were isolated using laser capture microdissection from five tissue samples of ALDH1-positive breast cancer patients. Messenger RNA expression levels were compared between ALDH1-positive and -negative cells. RESULTS: We found 104 differentially expressed genes between ALDH1-positive and -negative cells. Gene ontology and pathway analysis revealed that these genes were correlated with CSC functions and pathways. Network analyses identified 10 genes that were closely associated with ALDH1. We validated these 10 genes utilizing The Cancer Genome Atlas and the Molecular Taxonomy of Breast Cancer International Consortium cohort, and found that they were associated with ALDH1 expression and correlated with Wnt pathway signaling. CONCLUSION: The 10 genes we identified could be potential targets for CSC therapy of breast cancer.

Prediction of pathological complete response after neoadjuvant chemotherapy in breast cancer by combining magnetic resonance imaging and core needle biopsy.

BACKGROUND: Pathological complete response (pCR) is often achieved by neoadjuvant chemotherapy (NAC), particularly in hormone receptor-negative breast cancer. Contrast-enhanced magnetic resonance imaging (cMRI) is the most reliable imaging modality to evaluate the pathological effect of NAC. Ultrasonography is indispensable to collect representative specimens from the target lesion by core needle biopsy (CNB). This study aimed to evaluate the accuracy of predicting pCR by adding CNB after NAC, in cases with complete clinical response (cCR) diagnosed by cMRI. METHODS: In this prospective multicentre study, we evaluated patients diagnosed with cCR by cMRI after NAC. Ultrasound-guided CNB (uCNB) using a 14G needle was performed without clip markers under general anaesthesia as planned surgery. Specimens collected by uCNB were compared to those resected surgically and were categorized as (i) no carcinoma (ypT0), (ii) no invasive carcinoma and only residual carcinoma in situ (ypTis) and (iii) residual invasive carcinoma. The concordance of pathological results between the uCNB and surgical specimens was evaluated. RESULTS: Of the 83 patients evaluated, 41 (49.4%) and 17 (20.5%) of them had ypT0 and ypTis, respectively. The false negative rates (FNR), sensitivity and specificity for predicting ypT0 by uCNB were 50.0%, 50.0%, 100%, respectively, and those for predicting ypT0+ypTis were 28.0%, 72.0% and 98.3%, respectively. The concordance rates were 74.7% (62/83) for ypT0 and 90.4% (75/83) for ypT0+ypTis. CONCLUSION: In cCR cases diagnosed by cMRI, uCNB was not accurate enough to predict pCR. Additional modalities like clip placements and/or thicker core needles may be required for better prediction.

Development of an invasive ductal carcinoma in a contralateral composite nipple graft after an autologous breast reconstruction: a case report.

BACKGROUND: Nipple-areola complex (NAC) reconstruction is a technique used in breast reconstructive surgery, which is performed during the final stage of breast reconstruction after total mastectomy of primary breast cancer. Composite nipple grafts utilizing the contralateral NAC are common; however, to our knowledge, there are no reports of new primary invasive ductal carcinoma development within the graft. Here, we describe one such case for the first time. CASE PRESENTATION: A 54-year-old woman was referred to us by the Department of Plastic and Reconstructive Surgery in our medical center for further evaluation of right nipple erosion. She had undergone total mastectomy of the right breast following a breast cancer diagnosis 15 years ago, at which time tumor biological profiling revealed the following: estrogen receptor (ER), positive; progesterone receptor (PgR), negative; and human epidermal growth factor receptor 2 (HER2), undetermined. She received adjuvant chemotherapy and endocrine therapy. She defaulted endocrine therapy for a few years, and 7 years after surgery, she underwent autologous breast reconstruction with a deep inferior epigastric perforator (DIEP) flap. In the following year, NAC reconstruction was performed using a composite graft technique. Seven years after the NAC reconstruction, erosion appeared on the nipple grafted from its contralateral counterpart; scrape cytology revealed malignancy. The skin on the right side of her chest around the NAC and subcutaneous fat tissue consisted of transferred tissue from the abdomen, as the DIEP flap and grafted nipple were located on the graft skin. The right nipple carcinoma arose from the tissue taken from the left nipple. Magnetic resonance imaging (MRI) or computed tomography showed no malignant findings in the left breast. As the malignant lesion seemed limited to the area around the grafted right nipple on MRI, surgical resection with sufficient lateral and deep margins was performed around the right nipple. Pathological findings revealed invasive ductal carcinoma with comedo ductal components infiltrating the graft skin and underlying adipose tissue. Immunohistochemistry revealed positive for ER, PgR, and HER2. CONCLUSIONS: To our knowledge, this is the first case involving the development of invasive ductal carcinoma in a nipple graft constructed on the skin of a DIEP flap, with the origin from the contralateral breast's nipple.

Diagnostic Value of Imaging Methods in the Histological Four Grading of Hepatocellular Carcinoma.

We attempted to establish an ultrasound (US) imaging-diagnostic system for histopathological grades of differentiation of hepatocellular carcinoma (HCC). We conducted a retrospective study of histopathologically confirmed 200 HCCs, classified as early (45 lesions), well- (31 lesions), moderately (68 lesions) or poorly differentiated (diff.) (56 lesions) HCCs. We performed grayscale US to estimate the presence/absence of halo and mosaic signs, Sonazoid contrast-enhanced US (CEUS) to determine vascularity (hypo/iso/hyper) of lesion in arterial and portal phase (PP), and echogenicity of lesion in post-vascular phase (PVP). All findings were of significance for the diagnosis of some (but not all) histological grades (p < 0.001-0.05). Combined findings with a relatively high diagnostic efficacy for early, poorly and moderately diff. HCC were a combination of absence of halo sign and isoechogenicity in PVP of CEUS (accuracy: 93.0%, AUC: 0.908), hypovascularity in PP (accuracy: 78.0%, area under the curve (AUC): 0.750), and a combination of isovascularity in PP and hypoechogenicity in PVP (accuracy: 75.0%, AUC: 0.739), respectively. On the other hand, neither any individual finding nor any combination of findings yielded an AUC of over 0.657 for the diagnosis of well-diff. HCC. Our study provides encouraging data on Sonazoid CEUS in the histological differential diagnosis of HCC, especially in early HCC, and the effectiveness of this imaging method should be further proved by prospective, large sample, multicenter studies.

Long-Term Outcomes of Immediate Autologous Breast Reconstruction for Breast Cancer Patients.

BACKGROUND: There is limited information on the oncological outcomes of immediate autologous breast reconstruction in the Asian population. This study aimed to evaluate the oncological outcomes of immediate one-stage autologous breast reconstruction using a free perforator flap for breast cancer patients at a single institution in Japan. METHODS: We retrospectively reviewed 239 patients who underwent immediate one-stage autologous breast reconstruction using a free perforator flap after skin- or nipple-sparing mastectomy. The whole breast was pathologically analyzed in 5-mm sections. Clinical and pathological data were collected from medical records. RESULTS: For tumor stage among the 239 patients, 101 (42.3%) had stage 0, 127 (53.1%) had stage I and II, and 11 (4.6%) had stage III. Twenty-three patients (9.6%) had margin involvement in the surgical specimen. Adjuvant chemotherapy was performed in 75 patients (30%), and endocrine therapy was administered in 153 patients (64%). Radiation therapy was performed in 15 patients (6.3%) because of multiple lymph node metastases or margin involvement. With a median follow-up time of 73 mo, local recurrence was found in 3.3%, distant metastases in 2.5%, and contralateral breast cancer in 3.7%. All patients with local recurrence did not receive radiation therapy as adjuvant treatment. CONCLUSIONS: Among the patients who underwent immediate one-stage autologous reconstruction after breast surgery, 3.3% had local recurrence. For patients with margin involvement, radiation therapy is a promising option.

Successful Resection of Cisplatin-Resistant Renal Pelvic Cancer after the Administration of Pembrolizumab as Second-Line Therapy.

Pembrolizumab has been used as a second-line systemic therapy for urothelial carcinoma. We herein report a case of cisplatin-resistant renal-pelvic urothelial carcinoma that was successfully resected after pembrolizumab treatment. A 74-year-old woman was referred to our hospital for further examination for gross hematuria and a renal-pelvis tumor. Retrograde pyelography showed a defect lesion in her renal pelvis and urinary cytology of the renal pelvis showed class V. Because staging CT could not deny lung metastasis, we planned to perform nephro-ureterectomy after evaluating the response to neoadjuvant chemotherapy. After three courses of gemcitabine and cisplatin chemotherapy, the original site showed progression; thus, nephro-ureterectomy was cancelled. We introduced pembrolizumab as a second-line therapy. After four courses of pembrolizumab treatment, the size of the original lesion was significantly decreased. During these therapies the lung tumor size was unchanged; thus, we determined that the lung tumor was not metastatic and performed nephro-ureterectomy. A pathological examination demonstrated that the tumor was completely resected with a negative surgical margin. We described the first case in which cisplatin-resistant renal pelvic tumor was successfully resected after pembrolizumab treatment.

Long-Term Control of Metastatic Renal Cell Carcinoma Using Pazopanib.

COMPARZ study revealed no marked differences in terms of the progression free survival and overall survival between sunitinib and pazopanib treatment. Regarding the quality of life and early tumor shrinkage, pazopanib showed more favorable results than sunitinib treatment. A 70-year-old man underwent right nephrectomy in 2015. In 2017, iliac bone metastasis was found and consequently lung metastasis was developed. Pazopanib (200 mg × 4 tablets) was introduced. He showed no abnormal liver function markers during pazopanib treatment for more than two years and the size and number of lung metastases decreased. We herein report a case of successful control of metastatic renal cell carcinoma for more than two years using pazopanib treatment.

Anthracycline could be essential for triple-negative breast cancer: A randomised phase II study by the Kanagawa Breast Oncology Group (KBOG) 1101.

BACKGROUND: It is important to determine whether anthracycline-containing regimens or taxane-containing regimens are more effective in individual patients. The present study compared the efficacy of six cycles of docetaxel and cyclophosphamide (TC6) with that of three cycles of 5-fluorouracil, epirubicin and cyclophosphamide followed by docetaxel (FEC-D) in Japanese patients with hormone receptor (HR)-negative breast cancer (BC) to identify subtypes requiring anthracycline treatment. METHODS: The study included 103 patients with operable HR-negative BC. Of these patients 53 received FEC-D and 50 received TC6. The primary endpoint was pathological complete response (pCR). The secondary endpoints were safety, breast-conserving surgery, disease-free survival (DFS) and overall survival (OS). The predictive factors for each regimen were evaluated. RESULTS: Of the 103 patients, 97 completed the study (FEC-D, 50 patients; TC6, 47 patients). The pCR rate was higher with FEC-D (36%) than with TC6 (25.5%); however, the difference was not significant (P = 0.265). TC6 was safer than FEC-D, as the adverse events with docetaxel in the FEC-D regimen were similar to those with the TC6 regimen. Among patients with basal BC, the pCR rate was significantly higher with FEC-D (42.9%) than with TC6 (13.6%; P = 0.033). Among patients with triple-negative breast cancer (TNBC), the DFS and OS were significantly better with FEC-D than with TC6 (P = 0.016 and P = 0.034, respectively). CONCLUSION: TC6 was not as effective as FEC-D for treating HR-negative BC, as TC6 was not sufficient to treat TNBC, particularly the basal subtype. Our findings suggest that anthracyclines are better treatment options than taxanes for basal BC.

Myoepithelioma-like tumor of the vulvar region showing infiltrative growth and harboring only a few estrogen receptor-positive cells: A case report.

Recently, a new entity "myoepithelioma-like tumor of the vulvar region (MELTVR)" was proposed as a rare mesenchymal neoplasm arising in vulvar regions of adult women. While MELTVRs morphologically resemble soft tissue myoepitheliomas and extraskeletal myxoid chondrosarcomas, they have a unique immunohistochemical profile (positive for epithelial membrane antigen and estrogen receptor, negative for S100 protein and glial fibrillary acidic protein, and loss of INI1/SMARCB1 expression), and lack EWSR1 and NR4A3 gene rearrangement, as seen by fluorescence in situ hybridization. MELTVRs are usually well-demarcated tumors, with no reports of extensive infiltrative growth. In the current report, we present an unusual case of MELTVR showing infiltrative growth and harboring only a few estrogen receptor-positive cells, which might indicate a variation in this rare tumor.

Clear cell adenocarcinoma of the prostatic urethra: A case report.

INTRODUCTION: Clear cell adenocarcinoma of the prostatic urethra in men is an extremely rare disease, with only eight case reports published. CASE PRESENTATION: A 56-year-old man visited our hospital for gross hematuria. Urinary cytology detected class V, cystoscopy showed no abnormal findings, and contrast-enhanced computed tomography also showed no abnormal findings in his upper urinary tract except for a low-enhancement lesion on his left prostate lobe. Magnetic resonance imaging revealed a cystic lesion surrounding the prostate that was suspected of being urethral or prostate cancer, so transurethral resection was performed. A papillary tumor was detected at the prostatic urethra, and after resecting this tumor, a cavity showing multiple tumors was observed. The final pathological diagnosis was clear cell adenocarcinoma. Laparoscopic radical cystectomy and urethrectomy were thus performed. The pathological diagnosis was the same as at the primary tumor site. CONCLUSION: We herein report a case of clear cell adenocarcinoma of the prostatic urethra.