Urachal cancer-current concepts of a rare cancer.

Urachal cancer is a rare but aggressive disease. In addition to the non-glandular tumors, non-cystic urachal adenocarcinomas are nowadays distinguished from the primary cystic variant. (Immunohistochemical) markers are only of minor differential diagnostic value and, therefore, the diagnosis is primarily established in a multidisciplinary approach. The non-cystic variant accounts for the majority of cases (83%), is more common in men (63%), shows a median age at diagnosis of 51 years and has a 5-year survival rate of about 50%. In organ-confined disease, usually a partial cystectomy of the tumor in the bladder dome, including the median umbilical ligament and umbilicus, is performed. In advanced stages, systemic therapy is needed while 5­fuorouracil (5-FU) containing regimes have been shown to be more effective. Due to the rarity of the tumor, targeted therapy approaches based on a biological rationale are becoming increasingly relevant. As molecular data are still sparse, we compiled and analyzed the largest urachal cancer cohort to date. In 31% of the cases, MAPK-/PI3K signaling pathway alterations were detected (especially in K-/NRAS) with implications for anti-EGFR therapy approaches. Further potentially therapeutic alterations were detected in FGFR1, MET, PDGFRA, and erbB2/HER2. Additionally, PD-L1 tumor cell expression (clone: 22C3) was demonstrated in 16% of cases, therefore making anti-PD-1/PD-L1 immuno-oncological approaches worth considering despite the absence of mismatch repair deficiency (MMR-d) and/or high microsatellite instability (MSI-h). Finally, urachal adenocarcinomas seem to be a distinct entity on the molecular level with closer resemblance to colorectal adenocarcinomas than to urothelial carcinomas.

Morphological-metabolic evaluation of the urachal mucinous adenocarcinoma by positron emission tomography-computed tomography (PET-CT).

The urachal mucinous adenocarcinoma is a rare malignant neoplasm located between the bladder and the umbilicus. It is usually found in an advanced stage at the moment of diagnosis. We have analyzed a clinical case in which the PET-CT study provided valuable morphological and metabolic information for diagnosis and staging.

Urachal adenocarcinoma metastatic to the ovaries: case report and literature review.

We report a urachal adenocarcinoma metastatic to both ovaries in a 50-year-old Japanese woman. Pelvic examination and imaging studies revealed a large cystic tumor occupying the pelvis and another cystic tumor between the umbilicus and the urinary bladder. A laparotomy was performed. Histopathological examination revealed a urachal tumor that was a well-differentiated invasive mucinous adenocarcinoma; the overlying urothelium was intact. The right and left ovarian tumors were well-differentiated mucinous adenocarcinomas. The urachal and ovarian tumors were immunoreactive for cytokeratin 20 and carcinoembryonic antigen, but negative for cytokeratin 7. The patient is alive with lymph node and bone metastases 6 months postoperatively. This is the eighth reported case of an adenocarcinoma of the bladder with ovarian metastasis.

Prostatic specific antigen: immunoreactivity in urachal remnants.

Urachal remnants were obtained at autopsy from 10 males and 15 females in order to determine whether prostatic specific antigen (PSA) is present in that tissue. Immunohistochemical staining was carried out using a commercially available antibody to PSA. Four cases (three females and one male) showed focal positive reaction of PSA, predominantly in narrow glandular structures of metaplastic origin. Therefore, it cannot be excluded that PSA might occur in urachal adenocarcinomas. PSA-staining is evidently not confined exclusively to tissue originating in the prostate.